CURL(1)
Transfer data from or to a server. Static snapshot from Ubuntu 24.04.5 LTS.
curl(1) curl Manual curl(1)
NAME
curl - transfer a URL
SYNOPSIS
curl [options / URLs]
DESCRIPTION
curl is a tool for transferring data from or to a server using URLs. It sup‐
ports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS,
IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP,
SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS.
curl is powered by libcurl for all transfer-related features. See libcurl(3)
for details.
URL
The URL syntax is protocol-dependent. You find a detailed description in RFC
3986.
If you provide a URL without a leading protocol:// scheme, curl guesses what
protocol you want. It then defaults to HTTP but assumes others based on of‐
ten-used host name prefixes. For example, for host names starting with "ftp."
curl assumes you want FTP.
You can specify any amount of URLs on the command line. They are fetched in a
sequential manner in the specified order unless you use -Z, --parallel. You
can specify command line options and URLs mixed and in any order on the com‐
mand line.
curl attempts to reuse connections when doing multiple transfers, so that get‐
ting many files from the same server do not use multiple connects and setup
handshakes. This improves speed. Connection reuse can only be done for URLs
specified for a single command line invocation and cannot be performed between
separate curl runs.
Provide an IPv6 zone id in the URL with an escaped percentage sign. Like in
"http://[fe80::3%25eth0]/"
Everything provided on the command line that is not a command line option or
its argument, curl assumes is a URL and treats it as such.
GLOBBING
You can specify multiple URLs or parts of URLs by writing lists within braces
or ranges within brackets. We call this "globbing".
Provide a list with three different names like this:
"http://site.{one,two,three}.com"
or you can get sequences of alphanumeric series by using [] as in:
"ftp://ftp.example.com/file[1-100].txt"
"ftp://ftp.example.com/file[001-100].txt" (with leading zeros)
"ftp://ftp.example.com/file[a-z].txt"
Nested sequences are not supported, but you can use several ones next to each
other:
"http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html"
You can specify a step counter for the ranges to get every Nth number or let‐
ter:
"http://example.com/file[1-100:10].txt"
"http://example.com/file[a-z:2].txt"
When using [] or {} sequences when invoked from a command line prompt, you
probably have to put the full URL within double quotes to avoid the shell from
interfering with it. This also goes for other characters treated special, like
for example '&', '?' and '*'.
Switch off globbing with -g, --globoff.
VARIABLES
curl supports command line variables (added in 8.3.0). Set variables with
--variable name=content or --variable name@file (where "file" can be stdin if
set to a single dash (-)).
Variable contents can expanded in option parameters using "{{name}}" (without
the quotes) if the option name is prefixed with "--expand-". This gets the
contents of the variable "name" inserted, or a blank if the name does not ex‐
ist as a variable. Insert "{{" verbatim in the string by prefixing it with a
backslash, like "\{{".
You an access and expand environment variables by first importing them. You
can select to either require the environment variable to be set or you can
provide a default value in case it is not already set. Plain --variable %name
imports the variable called 'name' but exits with an error if that environment
variable is not already set. To provide a default value if it is not set, use
--variable %name=content or --variable %name@content.
Example. Get the USER environment variable into the URL, fail if USER is not
set:
--variable '%USER'
--expand-url = "https://example.com/api/{{USER}}/method"
When expanding variables, curl supports a set of functions that can make the
variable contents more convenient to use. It can trim leading and trailing
white space with trim, it can output the contents as a JSON quoted string with
json, URL encode the string with url or base64 encode it with b64. You apply
function to a variable expansion, add them colon separated to the right side
of the variable. Variable content holding null bytes that are not encoded when
expanded cause error.
Example: get the contents of a file called $HOME/.secret into a variable
called "fix". Make sure that the content is trimmed and percent-encoded sent
as POST data:
--variable %HOME
--expand-variable fix@{{HOME}}/.secret
--expand-data "{{fix:trim:url}}"
https://example.com/
Command line variables and expansions were added in in 8.3.0.
OUTPUT
If not told otherwise, curl writes the received data to stdout. It can be in‐
structed to instead save that data into a local file, using the -o, --output
or -O, --remote-name options. If curl is given multiple URLs to transfer on
the command line, it similarly needs multiple options for where to save them.
curl does not parse or otherwise "understand" the content it gets or writes as
output. It does no encoding or decoding, unless explicitly asked to with dedi‐
cated command line options.
PROTOCOLS
curl supports numerous protocols, or put in URL terms: schemes. Your particu‐
lar build may not support them all.
DICT Lets you lookup words using online dictionaries.
FILE Read or write local files. curl does not support accessing file:// URL
remotely, but when running on Microsoft Windows using the native UNC
approach works.
FTP(S) curl supports the File Transfer Protocol with a lot of tweaks and
levers. With or without using TLS.
GOPHER(S)
Retrieve files.
HTTP(S)
curl supports HTTP with numerous options and variations. It can speak
HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build options and the
correct command line options.
IMAP(S)
Using the mail reading protocol, curl can "download" emails for you.
With or without using TLS.
LDAP(S)
curl can do directory lookups for you, with or without TLS.
MQTT curl supports MQTT version 3. Downloading over MQTT equals "subscribe"
to a topic while uploading/posting equals "publish" on a topic. MQTT
over TLS is not supported (yet).
POP3(S)
Downloading from a pop3 server means getting a mail. With or without
using TLS.
RTMP(S)
The Realtime Messaging Protocol is primarily used to serve streaming
media and curl can download it.
RTSP curl supports RTSP 1.0 downloads.
SCP curl supports SSH version 2 scp transfers.
SFTP curl supports SFTP (draft 5) done over SSH version 2.
SMB(S) curl supports SMB version 1 for upload and download.
SMTP(S)
Uploading contents to an SMTP server means sending an email. With or
without TLS.
TELNET Telling curl to fetch a telnet URL starts an interactive session where
it sends what it reads on stdin and outputs what the server sends it.
TFTP curl can do TFTP downloads and uploads.
PROGRESS METER
curl normally displays a progress meter during operations, indicating the
amount of transferred data, transfer speeds and estimated time left, etc. The
progress meter displays the transfer rate in bytes per second. The suffixes
(k, M, G, T, P) are 1024 based. For example 1k is 1024 bytes. 1M is 1048576
bytes.
curl displays this data to the terminal by default, so if you invoke curl to
do an operation and it is about to write data to the terminal, it disables the
progress meter as otherwise it would mess up the output mixing progress meter
and response data.
If you want a progress meter for HTTP POST or PUT requests, you need to redi‐
rect the response output to a file, using shell redirect (>), -o, --output or
similar.
This does not apply to FTP upload as that operation does not spit out any re‐
sponse data to the terminal.
If you prefer a progress "bar" instead of the regular meter, -#,
--progress-bar is your friend. You can also disable the progress meter com‐
pletely with the -s, --silent option.
VERSION
This man page describes curl 8.5.0. If you use a later version, chances are
this man page does not fully document it. If you use an earlier version, this
document tries to include version information about which specific version
that introduced changes.
You can always learn which the latest curl version is by running
curl https://curl.se/info
The online version of this man page is always showing the latest incarnation:
https://curl.se/docs/manpage.html
OPTIONS
Options start with one or two dashes. Many of the options require an addi‐
tional value next to them. If provided text does not start with a dash, it is
presumed to be and treated as a URL.
The short "single-dash" form of the options, -d for example, may be used with
or without a space between it and its value, although a space is a recommended
separator. The long "double-dash" form, -d, --data for example, requires a
space between it and its value.
Short version options that do not need any additional values can be used imme‐
diately next to each other, like for example you can specify all the options
-O, -L and -v at once as -OLv.
In general, all boolean options are enabled with --option and yet again dis‐
abled with --no-option. That is, you use the same option name but prefix it
with "no-". However, in this list we mostly only list and show the --option
version of them.
When -:, --next is used, it resets the parser state and you start again with a
clean option state, except for the options that are "global". Global options
retain their values and meaning even after -:, --next.
The following options are global: --fail-early, --libcurl, --parallel-immedi‐
ate, -Z, --parallel, -#, --progress-bar, --rate, -S, --show-error, --stderr,
--styled-output, --trace-ascii, --trace-config, --trace-ids, --trace-time,
--trace and -v, --verbose.
--abstract-unix-socket <path>
(HTTP) Connect through an abstract Unix domain socket, instead of using
the network. Note: netstat shows the path of an abstract socket pre‐
fixed with '@', however the <path> argument should not have this lead‐
ing character.
If --abstract-unix-socket is provided several times, the last set value
is used.
Example:
curl --abstract-unix-socket socketpath https://example.com
See also --unix-socket. Added in 7.53.0.
--alt-svc <file name>
(HTTPS) This option enables the alt-svc parser in curl. If the file
name points to an existing alt-svc cache file, that gets used. After a
completed transfer, the cache is saved to the file name again if it has
been modified.
Specify a "" file name (zero length) to avoid loading/saving and make
curl just handle the cache in memory.
If this option is used several times, curl loads contents from all the
files but the last one is used for saving.
--alt-svc can be used several times in a command line
Example:
curl --alt-svc svc.txt https://example.com
See also --resolve and --connect-to. Added in 7.64.1.
--anyauth
(HTTP) Tells curl to figure out authentication method by itself, and
use the most secure one the remote site claims to support. This is done
by first doing a request and checking the response-headers, thus possi‐
bly inducing an extra network round-trip. This is used instead of set‐
ting a specific authentication method, which you can do with --basic,
--digest, --ntlm, and --negotiate.
Using --anyauth is not recommended if you do uploads from stdin, since
it may require data to be sent twice and then the client must be able
to rewind. If the need should arise when uploading from stdin, the up‐
load operation fails.
Used together with -u, --user.
Providing --anyauth multiple times has no extra effect.
Example:
curl --anyauth --user me:pwd https://example.com
See also --proxy-anyauth, --basic and --digest.
-a, --append
(FTP SFTP) When used in an upload, this option makes curl append to the
target file instead of overwriting it. If the remote file does not ex‐
ist, it is created. Note that this flag is ignored by some SFTP servers
(including OpenSSH).
Providing -a, --append multiple times has no extra effect. Disable it
again with --no-append.
Example:
curl --upload-file local --append ftp://example.com/
See also -r, --range and -C, --continue-at.
--aws-sigv4 <provider1[:provider2[:region[:service]]]>
Use AWS V4 signature authentication in the transfer.
The provider argument is a string that is used by the algorithm when
creating outgoing authentication headers.
The region argument is a string that points to a geographic area of a
resources collection (region-code) when the region name is omitted from
the endpoint.
The service argument is a string that points to a function provided by
a cloud (service-code) when the service name is omitted from the end‐
point.
If --aws-sigv4 is provided several times, the last set value is used.
Example:
curl --aws-sigv4 "aws:amz:us-east-2:es" --user "key:secret" https://example.com
See also --basic and -u, --user. Added in 7.75.0.
--basic
(HTTP) Tells curl to use HTTP Basic authentication with the remote
host. This is the default and this option is usually pointless, unless
you use it to override a previously set option that sets a different
authentication method (such as --ntlm, --digest, or --negotiate).
Used together with -u, --user.
Providing --basic multiple times has no extra effect.
Example:
curl -u name:password --basic https://example.com
See also --proxy-basic.
--ca-native
(TLS) Tells curl to use the CA store from the native operating system
to verify the peer. By default, curl otherwise uses a CA store provided
in a single file or directory, but when using this option it interfaces
the operating system's own vault.
This option only works for curl on Windows when built to use OpenSSL.
When curl on Windows is built to use Schannel, this feature is implied
and curl then only uses the native CA store.
curl built with wolfSSL also supports this option (added in 8.3.0).
Providing --ca-native multiple times has no extra effect. Disable it
again with --no-ca-native.
Example:
curl --ca-native https://example.com
See also --cacert, --capath and -k, --insecure. Added in 8.2.0.
--cacert <file>
(TLS) Tells curl to use the specified certificate file to verify the
peer. The file may contain multiple CA certificates. The certificate(s)
must be in PEM format. Normally curl is built to use a default file for
this, so this option is typically used to alter that default file.
curl recognizes the environment variable named 'CURL_CA_BUNDLE' if it
is set, and uses the given path as a path to a CA cert bundle. This op‐
tion overrides that variable.
The windows version of curl automatically looks for a CA certs file
named 'curl-ca-bundle.crt', either in the same directory as curl.exe,
or in the Current Working Directory, or in any folder along your PATH.
(iOS and macOS only) If curl is built against Secure Transport, then
this option is supported for backward compatibility with other SSL en‐
gines, but it should not be set. If the option is not set, then curl
uses the certificates in the system and user Keychain to verify the
peer, which is the preferred method of verifying the peer's certificate
chain.
(Schannel only) This option is supported for Schannel in Windows 7 or
later (added in 7.60.0). This option is supported for backward compati‐
bility with other SSL engines; instead it is recommended to use Win‐
dows' store of root certificates (the default for Schannel).
If --cacert is provided several times, the last set value is used.
Example:
curl --cacert CA-file.txt https://example.com
See also --capath and -k, --insecure.
--capath <dir>
(TLS) Tells curl to use the specified certificate directory to verify
the peer. Multiple paths can be provided by separating them with ":"
(e.g. "path1:path2:path3"). The certificates must be in PEM format,
and if curl is built against OpenSSL, the directory must have been
processed using the c_rehash utility supplied with OpenSSL. Using --ca‐
path can allow OpenSSL-powered curl to make SSL-connections much more
efficiently than using --cacert if the --cacert file contains many CA
certificates.
If this option is set, the default capath value is ignored.
If --capath is provided several times, the last set value is used.
Example:
curl --capath /local/directory https://example.com
See also --cacert and -k, --insecure.
--cert-status
(TLS) Tells curl to verify the status of the server certificate by us‐
ing the Certificate Status Request (aka. OCSP stapling) TLS extension.
If this option is enabled and the server sends an invalid (e.g. ex‐
pired) response, if the response suggests that the server certificate
has been revoked, or no response at all is received, the verification
fails.
This is currently only implemented in the OpenSSL and GnuTLS backends.
Providing --cert-status multiple times has no extra effect. Disable it
again with --no-cert-status.
Example:
curl --cert-status https://example.com
See also --pinnedpubkey.
--cert-type <type>
(TLS) Tells curl what type the provided client certificate is using.
PEM, DER, ENG and P12 are recognized types.
The default type depends on the TLS backend and is usually PEM, however
for Secure Transport and Schannel it is P12. If -E, --cert is a pkcs11:
URI then ENG is the default type.
If --cert-type is provided several times, the last set value is used.
Example:
curl --cert-type PEM --cert file https://example.com
See also -E, --cert, --key and --key-type.
-E, --cert <certificate[:password]>
(TLS) Tells curl to use the specified client certificate file when get‐
ting a file with HTTPS, FTPS or another SSL-based protocol. The cer‐
tificate must be in PKCS#12 format if using Secure Transport, or PEM
format if using any other engine. If the optional password is not spec‐
ified, it is queried for on the terminal. Note that this option assumes
a certificate file that is the private key and the client certificate
concatenated. See -E, --cert and --key to specify them independently.
In the <certificate> portion of the argument, you must escape the char‐
acter ":" as "\:" so that it is not recognized as the password delim‐
iter. Similarly, you must escape the character "\" as "\\" so that it
is not recognized as an escape character.
If curl is built against OpenSSL library, and the engine pkcs11 is
available, then a PKCS#11 URI (RFC 7512) can be used to specify a cer‐
tificate located in a PKCS#11 device. A string beginning with "pkcs11:"
is interpreted as a PKCS#11 URI. If a PKCS#11 URI is provided, then the
--engine option is set as "pkcs11" if none was provided and the
--cert-type option is set as "ENG" if none was provided.
(iOS and macOS only) If curl is built against Secure Transport, then
the certificate string can either be the name of a certificate/private
key in the system or user keychain, or the path to a PKCS#12-encoded
certificate and private key. If you want to use a file from the current
directory, please precede it with "./" prefix, in order to avoid confu‐
sion with a nickname.
(Schannel only) Client certificates must be specified by a path expres‐
sion to a certificate store. (Loading PFX is not supported; you can im‐
port it to a store first). You can use "<store location>\<store
name>\<thumbprint>" to refer to a certificate in the system certifi‐
cates store, for example, "Curren‐
tUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a". Thumbprint is usu‐
ally a SHA-1 hex string which you can see in certificate details. Fol‐
lowing store locations are supported: CurrentUser, LocalMachine, Cur‐
rentService, Services, CurrentUserGroupPolicy, LocalMachineGroupPolicy
and LocalMachineEnterprise.
If -E, --cert is provided several times, the last set value is used.
Example:
curl --cert certfile --key keyfile https://example.com
See also --cert-type, --key and --key-type.
--ciphers <list of ciphers>
(TLS) Specifies which ciphers to use in the connection. The list of ci‐
phers must specify valid ciphers. Read up on SSL cipher list details on
this URL:
https://curl.se/docs/ssl-ciphers.html
If --ciphers is provided several times, the last set value is used.
Example:
curl --ciphers ECDHE-ECDSA-AES256-CCM8 https://example.com
See also --tlsv1.3, --tls13-ciphers and --proxy-ciphers.
--compressed-ssh
(SCP SFTP) Enables built-in SSH compression. This is a request, not an
order; the server may or may not do it.
Providing --compressed-ssh multiple times has no extra effect. Disable
it again with --no-compressed-ssh.
Example:
curl --compressed-ssh sftp://example.com/
See also --compressed. Added in 7.56.0.
--compressed
(HTTP) Request a compressed response using one of the algorithms curl
supports, and automatically decompress the content.
Response headers are not modified when saved, so if they are "inter‐
preted" separately again at a later point they might appear to be say‐
ing that the content is (still) compressed; while in fact it has al‐
ready been decompressed.
If this option is used and the server sends an unsupported encoding,
curl reports an error. This is a request, not an order; the server may
or may not deliver data compressed.
Providing --compressed multiple times has no extra effect. Disable it
again with --no-compressed.
Example:
curl --compressed https://example.com
See also --compressed-ssh.
-K, --config <file>
Specify a text file to read curl arguments from. The command line argu‐
ments found in the text file are used as if they were provided on the
command line.
Options and their parameters must be specified on the same line in the
file, separated by whitespace, colon, or the equals sign. Long option
names can optionally be given in the config file without the initial
double dashes and if so, the colon or equals characters can be used as
separators. If the option is specified with one or two dashes, there
can be no colon or equals character between the option and its parame‐
ter.
If the parameter contains whitespace or starts with a colon (:) or
equals sign (=), it must be specified enclosed within double quotes
("). Within double quotes the following escape sequences are available:
\\, \", \t, \n, \r and \v. A backslash preceding any other letter is
ignored.
If the first non-blank column of a config line is a '#' character, that
line is treated as a comment.
Only write one option per physical line in the config file. A single
line is required to be no more than 10 megabytes (since 8.2.0).
Specify the filename to -K, --config as '-' to make curl read the file
from stdin.
Note that to be able to specify a URL in the config file, you need to
specify it using the --url option, and not by simply writing the URL on
its own line. So, it could look similar to this:
url = "https://curl.se/docs/"
# --- Example file ---
# this is a comment
url = "example.com"
output = "curlhere.html"
user-agent = "superagent/1.0"
# and fetch another URL too
url = "example.com/docs/manpage.html"
-O
referer = "http://nowhereatall.example.com/"
# --- End of example file ---
When curl is invoked, it (unless -q, --disable is used) checks for a
default config file and uses it if found, even when -K, --config is
used. The default config file is checked for in the following places in
this order:
1) "$CURL_HOME/.curlrc"
2) "$XDG_CONFIG_HOME/curlrc" (Added in 7.73.0)
3) "$HOME/.curlrc"
4) Windows: "%USERPROFILE%\.curlrc"
5) Windows: "%APPDATA%\.curlrc"
6) Windows: "%USERPROFILE%\Application Data\.curlrc"
7) Non-Windows: use getpwuid to find the home directory
8) On Windows, if it finds no .curlrc file in the sequence described
above, it checks for one in the same dir the curl executable is placed.
On Windows two filenames are checked per location: .curlrc and _curlrc,
preferring the former. Older versions on Windows checked for _curlrc
only.
-K, --config can be used several times in a command line
Example:
curl --config file.txt https://example.com
See also -q, --disable.
--connect-timeout <fractional seconds>
Maximum time in seconds that you allow curl's connection to take. This
only limits the connection phase, so if curl connects within the given
period it continues - if not it exits.
This option accepts decimal values. The decimal value needs to be pro‐
vided using a dot (.) as decimal separator - not the local version even
if it might be using another separator.
The connection phase is considered complete when the DNS lookup and re‐
quested TCP, TLS or QUIC handshakes are done.
If --connect-timeout is provided several times, the last set value is
used.
Examples:
curl --connect-timeout 20 https://example.com
curl --connect-timeout 3.14 https://example.com
See also -m, --max-time.
--connect-to <HOST1:PORT1:HOST2:PORT2>
For a request to the given HOST1:PORT1 pair, connect to HOST2:PORT2 in‐
stead. This option is suitable to direct requests at a specific
server, e.g. at a specific cluster node in a cluster of servers. This
option is only used to establish the network connection. It does NOT
affect the hostname/port that is used for TLS/SSL (e.g. SNI, certifi‐
cate verification) or for the application protocols. "HOST1" and
"PORT1" may be the empty string, meaning "any host/port". "HOST2" and
"PORT2" may also be the empty string, meaning "use the request's origi‐
nal host/port".
A "host" specified to this option is compared as a string, so it needs
to match the name used in request URL. It can be either numerical such
as "127.0.0.1" or the full host name such as "example.org".
--connect-to can be used several times in a command line
Example:
curl --connect-to example.com:443:example.net:8443 https://example.com
See also --resolve and -H, --header.
-C, --continue-at <offset>
Continue/Resume a previous file transfer at the given offset. The given
offset is the exact number of bytes that are skipped, counting from the
beginning of the source file before it is transferred to the destina‐
tion. If used with uploads, the FTP server command SIZE is not used by
curl.
Use "-C -" to tell curl to automatically find out where/how to resume
the transfer. It then uses the given output/input files to figure that
out.
If -C, --continue-at is provided several times, the last set value is
used.
Examples:
curl -C - https://example.com
curl -C 400 https://example.com
See also -r, --range.
-c, --cookie-jar <filename>
(HTTP) Specify to which file you want curl to write all cookies after a
completed operation. Curl writes all cookies from its in-memory cookie
storage to the given file at the end of operations. If no cookies are
known, no data is written. The file is created using the Netscape
cookie file format. If you set the file name to a single dash, "-", the
cookies are written to stdout.
The file specified with -c, --cookie-jar is only used for output. No
cookies are read from the file. To read cookies, use the -b, --cookie
option. Both options can specify the same file.
This command line option activates the cookie engine that makes curl
record and use cookies. The -b, --cookie option also activates it.
If the cookie jar cannot be created or written to, the whole curl oper‐
ation does not fail or even report an error clearly. Using -v, --ver‐
bose gets a warning displayed, but that is the only visible feedback
you get about this possibly lethal situation.
If -c, --cookie-jar is provided several times, the last set value is
used.
Examples:
curl -c store-here.txt https://example.com
curl -c store-here.txt -b read-these https://example.com
See also -b, --cookie.
-b, --cookie <data|filename>
(HTTP) Pass the data to the HTTP server in the Cookie header. It is
supposedly the data previously received from the server in a
"Set-Cookie:" line. The data should be in the format "NAME1=VALUE1;
NAME2=VALUE2". This makes curl use the cookie header with this content
explicitly in all outgoing request(s). If multiple requests are done
due to authentication, followed redirects or similar, they all get this
cookie passed on.
If no '=' symbol is used in the argument, it is instead treated as a
filename to read previously stored cookie from. This option also acti‐
vates the cookie engine which makes curl record incoming cookies, which
may be handy if you are using this in combination with the -L, --loca‐
tion option or do multiple URL transfers on the same invoke. If the
file name is exactly a minus ("-"), curl instead reads the contents
from stdin.
The file format of the file to read cookies from should be plain HTTP
headers (Set-Cookie style) or the Netscape/Mozilla cookie file format.
The file specified with -b, --cookie is only used as input. No cookies
are written to the file. To store cookies, use the -c, --cookie-jar op‐
tion.
If you use the Set-Cookie file format and do not specify a domain then
the cookie is not sent since the domain never matches. To address this,
set a domain in Set-Cookie line (doing that includes subdomains) or
preferably: use the Netscape format.
Users often want to both read cookies from a file and write updated
cookies back to a file, so using both -b, --cookie and -c, --cookie-jar
in the same command line is common.
-b, --cookie can be used several times in a command line
Examples:
curl -b cookiefile https://example.com
curl -b cookiefile -c cookiefile https://example.com
See also -c, --cookie-jar and -j, --junk-session-cookies.
--create-dirs
When used in conjunction with the -o, --output option, curl creates the
necessary local directory hierarchy as needed. This option creates the
directories mentioned with the -o, --output option combined with the
path possibly set with --output-dir. If the combined output file name
uses no directory, or if the directories it mentions already exist, no
directories are created.
Created directories are made with mode 0750 on unix style file systems.
To create remote directories when using FTP or SFTP, try --ftp-cre‐
ate-dirs.
Providing --create-dirs multiple times has no extra effect. Disable it
again with --no-create-dirs.
Example:
curl --create-dirs --output local/dir/file https://example.com
See also --ftp-create-dirs and --output-dir.
--create-file-mode <mode>
(SFTP SCP FILE) When curl is used to create files remotely using one of
the supported protocols, this option allows the user to set which
'mode' to set on the file at creation time, instead of the default
0644.
This option takes an octal number as argument.
If --create-file-mode is provided several times, the last set value is
used.
Example:
curl --create-file-mode 0777 -T localfile sftp://example.com/new
See also --ftp-create-dirs. Added in 7.75.0.
--crlf (FTP SMTP) Convert line feeds to carriage return plus line feeds in up‐
load. Useful for MVS (OS/390).
(SMTP added in 7.40.0)
Providing --crlf multiple times has no extra effect. Disable it again
with --no-crlf.
Example:
curl --crlf -T file ftp://example.com/
See also -B, --use-ascii.
--crlfile <file>
(TLS) Provide a file using PEM format with a Certificate Revocation
List that may specify peer certificates that are to be considered re‐
voked.
If --crlfile is provided several times, the last set value is used.
Example:
curl --crlfile rejects.txt https://example.com
See also --cacert and --capath.
--curves <algorithm list>
(TLS) Tells curl to request specific curves to use during SSL session
establishment according to RFC 8422, 5.1. Multiple algorithms can be
provided by separating them with ":" (e.g. "X25519:P-521"). The para‐
meter is available identically in the "openssl s_client/s_server" util‐
ities.
--curves allows a OpenSSL powered curl to make SSL-connections with ex‐
actly the (EC) curve requested by the client, avoiding nontransparent
client/server negotiations.
If this option is set, the default curves list built into OpenSSL are
ignored.
If --curves is provided several times, the last set value is used.
Example:
curl --curves X25519 https://example.com
See also --ciphers. Added in 7.73.0.
--data-ascii <data>
(HTTP) This is just an alias for -d, --data.
--data-ascii can be used several times in a command line
Example:
curl --data-ascii @file https://example.com
See also --data-binary, --data-raw and --data-urlencode.
--data-binary <data>
(HTTP) This posts data exactly as specified with no extra processing
whatsoever.
If you start the data with the letter @, the rest should be a filename.
Data is posted in a similar manner as -d, --data does, except that new‐
lines and carriage returns are preserved and conversions are never
done.
Like -d, --data the default content-type sent to the server is applica‐
tion/x-www-form-urlencoded. If you want the data to be treated as arbi‐
trary binary data by the server then set the content-type to
octet-stream: -H "Content-Type: application/octet-stream".
If this option is used several times, the ones following the first ap‐
pend data as described in -d, --data.
--data-binary can be used several times in a command line
Example:
curl --data-binary @filename https://example.com
See also --data-ascii.
--data-raw <data>
(HTTP) This posts data similarly to -d, --data but without the special
interpretation of the @ character.
--data-raw can be used several times in a command line
Examples:
curl --data-raw "hello" https://example.com
curl --data-raw "@at@at@" https://example.com
See also -d, --data.
--data-urlencode <data>
(HTTP) This posts data, similar to the other -d, --data options with
the exception that this performs URL-encoding.
To be CGI-compliant, the <data> part should begin with a name followed
by a separator and a content specification. The <data> part can be
passed to curl using one of the following syntaxes:
content
This makes curl URL-encode the content and pass that on. Just be
careful so that the content does not contain any = or @ symbols,
as that makes the syntax match one of the other cases below!
=content
This makes curl URL-encode the content and pass that on. The
preceding = symbol is not included in the data.
name=content
This makes curl URL-encode the content part and pass that on.
Note that the name part is expected to be URL-encoded already.
@filename
This makes curl load data from the given file (including any
newlines), URL-encode that data and pass it on in the POST.
name@filename
This makes curl load data from the given file (including any
newlines), URL-encode that data and pass it on in the POST. The
name part gets an equal sign appended, resulting in name=urlen‐
coded-file-content. Note that the name is expected to be URL-en‐
coded already.
--data-urlencode can be used several times in a command line
Examples:
curl --data-urlencode name=val https://example.com
curl --data-urlencode =encodethis https://example.com
curl --data-urlencode name@file https://example.com
curl --data-urlencode @fileonly https://example.com
See also -d, --data and --data-raw.
-d, --data <data>
(HTTP MQTT) Sends the specified data in a POST request to the HTTP
server, in the same way that a browser does when a user has filled in
an HTML form and presses the submit button. This makes curl pass the
data to the server using the content-type application/x-www-form-urlen‐
coded. Compare to -F, --form.
--data-raw is almost the same but does not have a special interpreta‐
tion of the @ character. To post data purely binary, you should instead
use the --data-binary option. To URL-encode the value of a form field
you may use --data-urlencode.
If any of these options is used more than once on the same command
line, the data pieces specified are merged with a separating &-symbol.
Thus, using '-d name=daniel -d skill=lousy' would generate a post chunk
that looks like 'name=daniel&skill=lousy'.
If you start the data with the letter @, the rest should be a file name
to read the data from, or - if you want curl to read the data from
stdin. Posting data from a file named 'foobar' would thus be done with
-d, --data @foobar. When -d, --data is told to read from a file like
that, carriage returns and newlines are stripped out. If you do not
want the @ character to have a special interpretation use --data-raw
instead.
The data for this option is passed on to the server exactly as provided
on the command line. curl does not convert, change or improve it. It is
up to the user to provide the data in the correct form.
-d, --data can be used several times in a command line
Examples:
curl -d "name=curl" https://example.com
curl -d "name=curl" -d "tool=cmdline" https://example.com
curl -d @filename https://example.com
See also --data-binary, --data-urlencode and --data-raw. This option is
mutually exclusive to -F, --form and -I, --head and -T, --upload-file.
--delegation <LEVEL>
(GSS/kerberos) Set LEVEL to tell the server what it is allowed to dele‐
gate when it comes to user credentials.
none Do not allow any delegation.
policy Delegates if and only if the OK-AS-DELEGATE flag is set in the
Kerberos service ticket, which is a matter of realm policy.
always Unconditionally allow the server to delegate.
If --delegation is provided several times, the last set value is used.
Example:
curl --delegation "none" https://example.com
See also -k, --insecure and --ssl.
--digest
(HTTP) Enables HTTP Digest authentication. This is an authentication
scheme that prevents the password from being sent over the wire in
clear text. Use this in combination with the normal -u, --user option
to set user name and password.
Providing --digest multiple times has no extra effect. Disable it
again with --no-digest.
Example:
curl -u name:password --digest https://example.com
See also -u, --user, --proxy-digest and --anyauth. This option is mutu‐
ally exclusive to --basic and --ntlm and --negotiate.
--disable-eprt
(FTP) Tell curl to disable the use of the EPRT and LPRT commands when
doing active FTP transfers. Curl normally first attempts to use EPRT
before using PORT, but with this option, it uses PORT right away. EPRT
is an extension to the original FTP protocol, and does not work on all
servers, but enables more functionality in a better way than the tradi‐
tional PORT command.
--eprt can be used to explicitly enable EPRT again and --no-eprt is an
alias for --disable-eprt.
If the server is accessed using IPv6, this option has no effect as EPRT
is necessary then.
Disabling EPRT only changes the active behavior. If you want to switch
to passive mode you need to not use -P, --ftp-port or force it with
--ftp-pasv.
Providing --disable-eprt multiple times has no extra effect. Disable
it again with --no-disable-eprt.
Example:
curl --disable-eprt ftp://example.com/
See also --disable-epsv and -P, --ftp-port.
--disable-epsv
(FTP) Tell curl to disable the use of the EPSV command when doing pas‐
sive FTP transfers. Curl normally first attempts to use EPSV before
PASV, but with this option, it does not try EPSV.
--epsv can be used to explicitly enable EPSV again and --no-epsv is an
alias for --disable-epsv.
If the server is an IPv6 host, this option has no effect as EPSV is
necessary then.
Disabling EPSV only changes the passive behavior. If you want to switch
to active mode you need to use -P, --ftp-port.
Providing --disable-epsv multiple times has no extra effect. Disable
it again with --no-disable-epsv.
Example:
curl --disable-epsv ftp://example.com/
See also --disable-eprt and -P, --ftp-port.
-q, --disable
If used as the first parameter on the command line, the curlrc config
file is not read or used. See the -K, --config for details on the de‐
fault config file search path.
Prior to 7.50.0 curl supported the short option name q but not the long
option name disable.
Providing -q, --disable multiple times has no extra effect. Disable it
again with --no-disable.
Example:
curl -q https://example.com
See also -K, --config.
--disallow-username-in-url
(HTTP) This tells curl to exit if passed a URL containing a username.
This is probably most useful when the URL is being provided at runtime
or similar.
Providing --disallow-username-in-url multiple times has no extra ef‐
fect. Disable it again with --no-disallow-username-in-url.
Example:
curl --disallow-username-in-url https://example.com
See also --proto. Added in 7.61.0.
--dns-interface <interface>
(DNS) Tell curl to send outgoing DNS requests through <interface>. This
option is a counterpart to --interface (which does not affect DNS). The
supplied string must be an interface name (not an address).
If --dns-interface is provided several times, the last set value is
used.
Example:
curl --dns-interface eth0 https://example.com
See also --dns-ipv4-addr and --dns-ipv6-addr. --dns-interface requires
that the underlying libcurl was built to support c-ares.
--dns-ipv4-addr <address>
(DNS) Tell curl to bind to a specific IP address when making IPv4 DNS
requests, so that the DNS requests originate from this address. The ar‐
gument should be a single IPv4 address.
If --dns-ipv4-addr is provided several times, the last set value is
used.
Example:
curl --dns-ipv4-addr 10.1.2.3 https://example.com
See also --dns-interface and --dns-ipv6-addr. --dns-ipv4-addr requires
that the underlying libcurl was built to support c-ares.
--dns-ipv6-addr <address>
(DNS) Tell curl to bind to a specific IP address when making IPv6 DNS
requests, so that the DNS requests originate from this address. The ar‐
gument should be a single IPv6 address.
If --dns-ipv6-addr is provided several times, the last set value is
used.
Example:
curl --dns-ipv6-addr 2a04:4e42::561 https://example.com
See also --dns-interface and --dns-ipv4-addr. --dns-ipv6-addr requires
that the underlying libcurl was built to support c-ares.
--dns-servers <addresses>
Set the list of DNS servers to be used instead of the system default.
The list of IP addresses should be separated with commas. Port numbers
may also optionally be given as :<port-number> after each IP address.
If --dns-servers is provided several times, the last set value is used.
Example:
curl --dns-servers 192.168.0.1,192.168.0.2 https://example.com
See also --dns-interface and --dns-ipv4-addr. --dns-servers requires
that the underlying libcurl was built to support c-ares.
--doh-cert-status
Same as --cert-status but used for DoH (DNS-over-HTTPS).
Providing --doh-cert-status multiple times has no extra effect. Dis‐
able it again with --no-doh-cert-status.
Example:
curl --doh-cert-status --doh-url https://doh.example https://example.com
See also --doh-insecure. Added in 7.76.0.
--doh-insecure
Same as -k, --insecure but used for DoH (DNS-over-HTTPS).
Providing --doh-insecure multiple times has no extra effect. Disable
it again with --no-doh-insecure.
Example:
curl --doh-insecure --doh-url https://doh.example https://example.com
See also --doh-url. Added in 7.76.0.
--doh-url <URL>
Specifies which DNS-over-HTTPS (DoH) server to use to resolve host‐
names, instead of using the default name resolver mechanism. The URL
must be HTTPS.
Some SSL options that you set for your transfer also applies to DoH
since the name lookups take place over SSL. However, the certificate
verification settings are not inherited but are controlled separately
via --doh-insecure and --doh-cert-status.
This option is unset if an empty string "" is used as the URL. (Added
in 7.85.0)
If --doh-url is provided several times, the last set value is used.
Example:
curl --doh-url https://doh.example https://example.com
See also --doh-insecure. Added in 7.62.0.
-D, --dump-header <filename>
(HTTP FTP) Write the received protocol headers to the specified file.
If no headers are received, the use of this option creates an empty
file.
When used in FTP, the FTP server response lines are considered being
"headers" and thus are saved there.
Having multiple transfers in one set of operations (i.e. the URLs in
one -:, --next clause), appends them to the same file, separated by a
blank line.
If -D, --dump-header is provided several times, the last set value is
used.
Example:
curl --dump-header store.txt https://example.com
See also -o, --output.
--egd-file <file>
(TLS) Deprecated option (added in 7.84.0). Prior to that it only had an
effect on curl if built to use old versions of OpenSSL.
Specify the path name to the Entropy Gathering Daemon socket. The
socket is used to seed the random engine for SSL connections.
If --egd-file is provided several times, the last set value is used.
Example:
curl --egd-file /random/here https://example.com
See also --random-file.
--engine <name>
(TLS) Select the OpenSSL crypto engine to use for cipher operations.
Use --engine list to print a list of build-time supported engines. Note
that not all (and possibly none) of the engines may be available at
runtime.
If --engine is provided several times, the last set value is used.
Example:
curl --engine flavor https://example.com
See also --ciphers and --curves.
--etag-compare <file>
(HTTP) This option makes a conditional HTTP request for the specific
ETag read from the given file by sending a custom If-None-Match header
using the stored ETag.
For correct results, make sure that the specified file contains only a
single line with the desired ETag. An empty file is parsed as an empty
ETag.
Use the option --etag-save to first save the ETag from a response, and
then use this option to compare against the saved ETag in a subsequent
request.
If --etag-compare is provided several times, the last set value is
used.
Example:
curl --etag-compare etag.txt https://example.com
See also --etag-save and -z, --time-cond. Added in 7.68.0.
--etag-save <file>
(HTTP) This option saves an HTTP ETag to the specified file. An ETag is
a caching related header, usually returned in a response.
If no ETag is sent by the server, an empty file is created.
If --etag-save is provided several times, the last set value is used.
Example:
curl --etag-save storetag.txt https://example.com
See also --etag-compare. Added in 7.68.0.
--expect100-timeout <seconds>
(HTTP) Maximum time in seconds that you allow curl to wait for a
100-continue response when curl emits an Expects: 100-continue header
in its request. By default curl waits one second. This option accepts
decimal values! When curl stops waiting, it continues as if the re‐
sponse has been received.
The decimal value needs to provided using a dot (.) as decimal separa‐
tor - not the local version even if it might be using another separa‐
tor.
If --expect100-timeout is provided several times, the last set value is
used.
Example:
curl --expect100-timeout 2.5 -T file https://example.com
See also --connect-timeout.
--fail-early
Fail and exit on the first detected transfer error.
When curl is used to do multiple transfers on the command line, it at‐
tempts to operate on each given URL, one by one. By default, it ignores
errors if there are more URLs given and the last URL's success deter‐
mines the error code curl returns. So early failures are "hidden" by
subsequent successful transfers.
Using this option, curl instead returns an error on the first transfer
that fails, independent of the amount of URLs that are given on the
command line. This way, no transfer failures go undetected by scripts
and similar.
This option does not imply -f, --fail, which causes transfers to fail
due to the server's HTTP status code. You can combine the two options,
however note -f, --fail is not global and is therefore contained by -:,
--next.
This option is global and does not need to be specified for each use of
--next.
Providing --fail-early multiple times has no extra effect. Disable it
again with --no-fail-early.
Example:
curl --fail-early https://example.com https://two.example
See also -f, --fail and --fail-with-body. Added in 7.52.0.
--fail-with-body
(HTTP) Return an error on server errors where the HTTP response code is
400 or greater). In normal cases when an HTTP server fails to deliver a
document, it returns an HTML document stating so (which often also de‐
scribes why and more). This flag allows curl to output and save that
content but also to return error 22.
This is an alternative option to -f, --fail which makes curl fail for
the same circumstances but without saving the content.
Providing --fail-with-body multiple times has no extra effect. Disable
it again with --no-fail-with-body.
Example:
curl --fail-with-body https://example.com
See also -f, --fail and --fail-early. This option is mutually exclusive
to -f, --fail. Added in 7.76.0.
-f, --fail
(HTTP) Fail fast with no output at all on server errors. This is useful
to enable scripts and users to better deal with failed attempts. In
normal cases when an HTTP server fails to deliver a document, it re‐
turns an HTML document stating so (which often also describes why and
more). This flag prevents curl from outputting that and return error
22.
This method is not fail-safe and there are occasions where non-success‐
ful response codes slip through, especially when authentication is in‐
volved (response codes 401 and 407).
Providing -f, --fail multiple times has no extra effect. Disable it
again with --no-fail.
Example:
curl --fail https://example.com
See also --fail-with-body and --fail-early. This option is mutually ex‐
clusive to --fail-with-body.
--false-start
(TLS) Tells curl to use false start during the TLS handshake. False
start is a mode where a TLS client starts sending application data be‐
fore verifying the server's Finished message, thus saving a round trip
when performing a full handshake.
This is currently only implemented in the Secure Transport (on iOS 7.0
or later, or OS X 10.9 or later) backend.
Providing --false-start multiple times has no extra effect. Disable it
again with --no-false-start.
Example:
curl --false-start https://example.com
See also --tcp-fastopen.
--form-escape
(HTTP) Tells curl to pass on names of multipart form fields and files
using backslash-escaping instead of percent-encoding.
If --form-escape is provided several times, the last set value is used.
Example:
curl --form-escape -F 'field\name=curl' -F 'file=@load"this' https://example.com
See also -F, --form. Added in 7.81.0.
--form-string <name=string>
(HTTP SMTP IMAP) Similar to -F, --form except that the value string for
the named parameter is used literally. Leading '@' and '<' characters,
and the ';type=' string in the value have no special meaning. Use this
in preference to -F, --form if there is any possibility that the string
value may accidentally trigger the '@' or '<' features of -F, --form.
--form-string can be used several times in a command line
Example:
curl --form-string "data" https://example.com
See also -F, --form.
-F, --form <name=content>
(HTTP SMTP IMAP) For HTTP protocol family, this lets curl emulate a
filled-in form in which a user has pressed the submit button. This
causes curl to POST data using the Content-Type multipart/form-data ac‐
cording to RFC 2388.
For SMTP and IMAP protocols, this is the means to compose a multipart
mail message to transmit.
This enables uploading of binary files etc. To force the 'content' part
to be a file, prefix the file name with an @ sign. To just get the con‐
tent part from a file, prefix the file name with the symbol <. The dif‐
ference between @ and < is then that @ makes a file get attached in the
post as a file upload, while the < makes a text field and just get the
contents for that text field from a file.
Tell curl to read content from stdin instead of a file by using - as
filename. This goes for both @ and < constructs. When stdin is used,
the contents is buffered in memory first by curl to determine its size
and allow a possible resend. Defining a part's data from a named
non-regular file (such as a named pipe or similar) is not subject to
buffering and is instead read at transmission time; since the full size
is unknown before the transfer starts, such data is sent as chunks by
HTTP and rejected by IMAP.
Example: send an image to an HTTP server, where 'profile' is the name
of the form-field to which the file portrait.jpg is the input:
curl -F profile=@portrait.jpg https://example.com/upload.cgi
Example: send your name and shoe size in two text fields to the server:
curl -F name=John -F shoesize=11 https://example.com/
Example: send your essay in a text field to the server. Send it as a
plain text field, but get the contents for it from a local file:
curl -F "story=<hugefile.txt" https://example.com/
You can also tell curl what Content-Type to use by using 'type=', in a
manner similar to:
curl -F "web=@index.html;type=text/html" example.com
or
curl -F "name=daniel;type=text/foo" example.com
You can also explicitly change the name field of a file upload part by
setting filename=, like this:
curl -F "file=@localfile;filename=nameinpost" example.com
If filename/path contains ',' or ';', it must be quoted by dou‐
ble-quotes like:
curl -F "file=@\"local,file\";filename=\"name;in;post\"" example.com
or
curl -F 'file=@"local,file";filename="name;in;post"' example.com
Note that if a filename/path is quoted by double-quotes, any dou‐
ble-quote or backslash within the filename must be escaped by back‐
slash.
Quoting must also be applied to non-file data if it contains semi‐
colons, leading/trailing spaces or leading double quotes:
curl -F 'colors="red; green; blue";type=text/x-myapp' example.com
You can add custom headers to the field by setting headers=, like
curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com
or
curl -F "submit=OK;headers=@headerfile" example.com
The headers= keyword may appear more that once and above notes about
quoting apply. When headers are read from a file, Empty lines and lines
starting with '#' are comments and ignored; each header can be folded
by splitting between two words and starting the continuation line with
a space; embedded carriage-returns and trailing spaces are stripped.
Here is an example of a header file contents:
# This file contain two headers.
X-header-1: this is a header
# The following header is folded.
X-header-2: this is
another header
To support sending multipart mail messages, the syntax is extended as
follows:
- name can be omitted: the equal sign is the first character of the ar‐
gument,
- if data starts with '(', this signals to start a new multipart: it
can be followed by a content type specification.
- a multipart can be terminated with a '=)' argument.
Example: the following command sends an SMTP mime email consisting in
an inline part in two alternative formats: plain text and HTML. It at‐
taches a text file:
curl -F '=(;type=multipart/alternative' \
-F '=plain text message' \
-F '= <body>HTML message</body>;type=text/html' \
-F '=)' -F '=@textfile.txt' ... smtp://example.com
Data can be encoded for transfer using encoder=. Available encodings
are binary and 8bit that do nothing else than adding the corresponding
Content-Transfer-Encoding header, 7bit that only rejects 8-bit charac‐
ters with a transfer error, quoted-printable and base64 that encodes
data according to the corresponding schemes, limiting lines length to
76 characters.
Example: send multipart mail with a quoted-printable text message and a
base64 attached file:
curl -F '=text message;encoder=quoted-printable' \
-F '=@localfile;encoder=base64' ... smtp://example.com
See further examples and details in the MANUAL.
-F, --form can be used several times in a command line
Example:
curl --form "name=curl" --form "file=@loadthis" https://example.com
See also -d, --data, --form-string and --form-escape. This option is
mutually exclusive to -d, --data and -I, --head and -T, --upload-file.
--ftp-account <data>
(FTP) When an FTP server asks for "account data" after user name and
password has been provided, this data is sent off using the ACCT com‐
mand.
If --ftp-account is provided several times, the last set value is used.
Example:
curl --ftp-account "mr.robot" ftp://example.com/
See also -u, --user.
--ftp-alternative-to-user <command>
(FTP) If authenticating with the USER and PASS commands fails, send
this command. When connecting to Tumbleweed's Secure Transport server
over FTPS using a client certificate, using "SITE AUTH" tells the
server to retrieve the username from the certificate.
If --ftp-alternative-to-user is provided several times, the last set
value is used.
Example:
curl --ftp-alternative-to-user "U53r" ftp://example.com
See also --ftp-account and -u, --user.
--ftp-create-dirs
(FTP SFTP) When an FTP or SFTP URL/operation uses a path that does not
currently exist on the server, the standard behavior of curl is to
fail. Using this option, curl instead attempts to create missing direc‐
tories.
Providing --ftp-create-dirs multiple times has no extra effect. Dis‐
able it again with --no-ftp-create-dirs.
Example:
curl --ftp-create-dirs -T file ftp://example.com/remote/path/file
See also --create-dirs.
--ftp-method <method>
(FTP) Control what method curl should use to reach a file on an FTP(S)
server. The method argument should be one of the following alterna‐
tives:
multicwd
curl does a single CWD operation for each path part in the given
URL. For deep hierarchies this means many commands. This is how
RFC 1738 says it should be done. This is the default but the
slowest behavior.
nocwd curl does no CWD at all. curl does SIZE, RETR, STOR etc and give
a full path to the server for all these commands. This is the
fastest behavior.
singlecwd
curl does one CWD with the full target directory and then oper‐
ates on the file "normally" (like in the multicwd case). This is
somewhat more standards compliant than 'nocwd' but without the
full penalty of 'multicwd'.
If --ftp-method is provided several times, the last set value is used.
Examples:
curl --ftp-method multicwd ftp://example.com/dir1/dir2/file
curl --ftp-method nocwd ftp://example.com/dir1/dir2/file
curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file
See also -l, --list-only.
--ftp-pasv
(FTP) Use passive mode for the data connection. Passive is the internal
default behavior, but using this option can be used to override a pre‐
vious -P, --ftp-port option.
Reversing an enforced passive really is not doable but you must then
instead enforce the correct -P, --ftp-port again.
Passive mode means that curl tries the EPSV command first and then
PASV, unless --disable-epsv is used.
Providing --ftp-pasv multiple times has no extra effect. Disable it
again with --no-ftp-pasv.
Example:
curl --ftp-pasv ftp://example.com/
See also --disable-epsv.
-P, --ftp-port <address>
(FTP) Reverses the default initiator/listener roles when connecting
with FTP. This option makes curl use active mode. curl then tells the
server to connect back to the client's specified address and port,
while passive mode asks the server to setup an IP address and port for
it to connect to. <address> should be one of:
interface
e.g. "eth0" to specify which interface's IP address you want to
use (Unix only)
IP address
e.g. "192.168.10.1" to specify the exact IP address
host name
e.g. "my.host.domain" to specify the machine
- make curl pick the same IP address that is already used for the
control connection
Disable the use of PORT with --ftp-pasv. Disable the attempt to use the
EPRT command instead of PORT by using --disable-eprt. EPRT is really
PORT++.
You can also append ":[start]-[end]" to the right of the address, to
tell curl what TCP port range to use. That means you specify a port
range, from a lower to a higher number. A single number works as well,
but do note that it increases the risk of failure since the port may
not be available.
If -P, --ftp-port is provided several times, the last set value is
used.
Examples:
curl -P - ftp:/example.com
curl -P eth0 ftp:/example.com
curl -P 192.168.0.2 ftp:/example.com
See also --ftp-pasv and --disable-eprt.
--ftp-pret
(FTP) Tell curl to send a PRET command before PASV (and EPSV). Certain
FTP servers, mainly drftpd, require this non-standard command for di‐
rectory listings as well as up and downloads in PASV mode.
Providing --ftp-pret multiple times has no extra effect. Disable it
again with --no-ftp-pret.
Example:
curl --ftp-pret ftp://example.com/
See also -P, --ftp-port and --ftp-pasv.
--ftp-skip-pasv-ip
(FTP) Tell curl to not use the IP address the server suggests in its
response to curl's PASV command when curl connects the data connection.
Instead curl reuses the same IP address it already uses for the control
connection.
This option is enabled by default (added in 7.74.0).
This option has no effect if PORT, EPRT or EPSV is used instead of
PASV.
Providing --ftp-skip-pasv-ip multiple times has no extra effect. Dis‐
able it again with --no-ftp-skip-pasv-ip.
Example:
curl --ftp-skip-pasv-ip ftp://example.com/
See also --ftp-pasv.
--ftp-ssl-ccc-mode <active/passive>
(FTP) Sets the CCC mode. The passive mode does not initiate the shut‐
down, but instead waits for the server to do it, and does not reply to
the shutdown from the server. The active mode initiates the shutdown
and waits for a reply from the server.
Providing --ftp-ssl-ccc-mode multiple times has no extra effect. Dis‐
able it again with --no-ftp-ssl-ccc-mode.
Example:
curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/
See also --ftp-ssl-ccc.
--ftp-ssl-ccc
(FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer af‐
ter authenticating. The rest of the control channel communication is be
unencrypted. This allows NAT routers to follow the FTP transaction. The
default mode is passive.
Providing --ftp-ssl-ccc multiple times has no extra effect. Disable it
again with --no-ftp-ssl-ccc.
Example:
curl --ftp-ssl-ccc ftps://example.com/
See also --ssl and --ftp-ssl-ccc-mode.
--ftp-ssl-control
(FTP) Require SSL/TLS for the FTP login, clear for transfer. Allows
secure authentication, but non-encrypted data transfers for efficiency.
Fails the transfer if the server does not support SSL/TLS.
Providing --ftp-ssl-control multiple times has no extra effect. Dis‐
able it again with --no-ftp-ssl-control.
Example:
curl --ftp-ssl-control ftp://example.com
See also --ssl.
-G, --get
When used, this option makes all data specified with -d, --data,
--data-binary or --data-urlencode to be used in an HTTP GET request in‐
stead of the POST request that otherwise would be used. The data is ap‐
pended to the URL with a '?' separator.
If used in combination with -I, --head, the POST data is instead ap‐
pended to the URL with a HEAD request.
Providing -G, --get multiple times has no extra effect. Disable it
again with --no-get.
Examples:
curl --get https://example.com
curl --get -d "tool=curl" -d "age=old" https://example.com
curl --get -I -d "tool=curl" https://example.com
See also -d, --data and -X, --request.
-g, --globoff
This option switches off the "URL globbing parser". When you set this
option, you can specify URLs that contain the letters {}[] without hav‐
ing curl itself interpret them. Note that these letters are not normal
legal URL contents but they should be encoded according to the URI
standard.
Providing -g, --globoff multiple times has no extra effect. Disable it
again with --no-globoff.
Example:
curl -g "https://example.com/{[]}}}}"
See also -K, --config and -q, --disable.
--happy-eyeballs-timeout-ms <milliseconds>
Happy Eyeballs is an algorithm that attempts to connect to both IPv4
and IPv6 addresses for dual-stack hosts, giving IPv6 a head-start of
the specified number of milliseconds. If the IPv6 address cannot be
connected to within that time, then a connection attempt is made to the
IPv4 address in parallel. The first connection to be established is the
one that is used.
The range of suggested useful values is limited. Happy Eyeballs RFC
6555 says "It is RECOMMENDED that connection attempts be paced 150-250
ms apart to balance human factors against network load." libcurl cur‐
rently defaults to 200 ms. Firefox and Chrome currently default to 300
ms.
If --happy-eyeballs-timeout-ms is provided several times, the last set
value is used.
Example:
curl --happy-eyeballs-timeout-ms 500 https://example.com
See also -m, --max-time and --connect-timeout. Added in 7.59.0.
--haproxy-clientip
(HTTP) Sets a client IP in HAProxy PROXY protocol v1 header at the be‐
ginning of the connection.
For valid requests, IPv4 addresses must be indicated as a series of ex‐
actly 4 integers in the range [0..255] inclusive written in decimal
representation separated by exactly one dot between each other. Heading
zeroes are not permitted in front of numbers in order to avoid any pos‐
sible confusion with octal numbers. IPv6 addresses must be indicated as
series of 4 hexadecimal digits (upper or lower case) delimited by
colons between each other, with the acceptance of one double colon se‐
quence to replace the largest acceptable range of consecutive zeroes.
The total number of decoded bits must exactly be 128.
Otherwise, any string can be accepted for the client IP and get sent.
It replaces --haproxy-protocol if used, it is not necessary to specify
both flags.
This option is primarily useful when sending test requests to verify a
service is working as intended.
If --haproxy-clientip is provided several times, the last set value is
used.
Example:
curl --haproxy-clientip $IP
See also -x, --proxy. Added in 8.2.0.
--haproxy-protocol
(HTTP) Send a HAProxy PROXY protocol v1 header at the beginning of the
connection. This is used by some load balancers and reverse proxies to
indicate the client's true IP address and port.
This option is primarily useful when sending test requests to a service
that expects this header.
Providing --haproxy-protocol multiple times has no extra effect. Dis‐
able it again with --no-haproxy-protocol.
Example:
curl --haproxy-protocol https://example.com
See also -x, --proxy. Added in 7.60.0.
-I, --head
(HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the com‐
mand HEAD which this uses to get nothing but the header of a document.
When used on an FTP or FILE file, curl displays the file size and last
modification time only.
Providing -I, --head multiple times has no extra effect. Disable it
again with --no-head.
Example:
curl -I https://example.com
See also -G, --get, -v, --verbose and --trace-ascii.
-H, --header <header/@file>
(HTTP IMAP SMTP) Extra header to include in information sent. When used
within an HTTP request, it is added to the regular request headers.
For an IMAP or SMTP MIME uploaded mail built with -F, --form options,
it is prepended to the resulting MIME document, effectively including
it at the mail global level. It does not affect raw uploaded mails
(Added in 7.56.0).
You may specify any number of extra headers. Note that if you should
add a custom header that has the same name as one of the internal ones
curl would use, your externally set header is used instead of the in‐
ternal one. This allows you to make even trickier stuff than curl would
normally do. You should not replace internally set headers without
knowing perfectly well what you are doing. Remove an internal header by
giving a replacement without content on the right side of the colon, as
in: -H "Host:". If you send the custom header with no-value then its
header must be terminated with a semicolon, such as -H "X-Cus‐
tom-Header;" to send "X-Custom-Header:".
curl makes sure that each header you add/replace is sent with the
proper end-of-line marker, you should thus not add that as a part of
the header content: do not add newlines or carriage returns, they only
mess things up for you. curl passes on the verbatim string you give it
without any filter or other safe guards. That includes white space and
control characters.
This option can take an argument in @filename style, which then adds a
header for each line in the input file. Using @- makes curl read the
header file from stdin. Added in 7.55.0.
Please note that most anti-spam utilities check the presence and value
of several MIME mail headers: these are "From:", "To:", "Date:" and
"Subject:" among others and should be added with this option.
You need --proxy-header to send custom headers intended for an HTTP
proxy. Added in 7.37.0.
Passing on a "Transfer-Encoding: chunked" header when doing an HTTP re‐
quest with a request body, makes curl send the data using chunked en‐
coding.
WARNING: headers set with this option are set in all HTTP requests -
even after redirects are followed, like when told with -L, --location.
This can lead to the header being sent to other hosts than the original
host, so sensitive headers should be used with caution combined with
following redirects.
-H, --header can be used several times in a command line
Examples:
curl -H "X-First-Name: Joe" https://example.com
curl -H "User-Agent: yes-please/2000" https://example.com
curl -H "Host:" https://example.com
curl -H @headers.txt https://example.com
See also -A, --user-agent and -e, --referer.
-h, --help <category>
Usage help. This lists all curl command line options within the given
category.
If no argument is provided, curl displays only the most important com‐
mand line arguments.
For category all, curl displays help for all options.
If category is specified, curl displays all available help categories.
Example:
curl --help all
See also -v, --verbose.
--hostpubmd5 <md5>
(SFTP SCP) Pass a string containing 32 hexadecimal digits. The string
should be the 128 bit MD5 checksum of the remote host's public key,
curl refuses the connection with the host unless the md5sums match.
If --hostpubmd5 is provided several times, the last set value is used.
Example:
curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/
See also --hostpubsha256.
--hostpubsha256 <sha256>
(SFTP SCP) Pass a string containing a Base64-encoded SHA256 hash of the
remote host's public key. Curl refuses the connection with the host un‐
less the hashes match.
This feature requires libcurl to be built with libssh2 and does not
work with other SSH backends.
If --hostpubsha256 is provided several times, the last set value is
used.
Example:
curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/
See also --hostpubmd5. Added in 7.80.0.
--hsts <file name>
(HTTPS) This option enables HSTS for the transfer. If the file name
points to an existing HSTS cache file, that is used. After a completed
transfer, the cache is saved to the file name again if it has been mod‐
ified.
If curl is told to use HTTP:// for a transfer involving a host name
that exists in the HSTS cache, it upgrades the transfer to use HTTPS.
Each HSTS cache entry has an individual life time after which the up‐
grade is no longer performed.
Specify a "" file name (zero length) to avoid loading/saving and make
curl just handle HSTS in memory.
If this option is used several times, curl loads contents from all the
files but the last one is used for saving.
--hsts can be used several times in a command line
Example:
curl --hsts cache.txt https://example.com
See also --proto. Added in 7.74.0.
--http0.9
(HTTP) Tells curl to be fine with HTTP version 0.9 response.
HTTP/0.9 is a response without headers and therefore you can also con‐
nect with this to non-HTTP servers and still get a response since curl
simply transparently downgrades - if allowed.
HTTP/0.9 is disabled by default (added in 7.66.0)
Providing --http0.9 multiple times has no extra effect. Disable it
again with --no-http0.9.
Example:
curl --http0.9 https://example.com
See also --http1.1, --http2 and --http3. Added in 7.64.0.
-0, --http1.0
(HTTP) Tells curl to use HTTP version 1.0 instead of using its inter‐
nally preferred HTTP version.
Providing -0, --http1.0 multiple times has no extra effect.
Example:
curl --http1.0 https://example.com
See also --http0.9 and --http1.1. This option is mutually exclusive to
--http1.1 and --http2 and --http2-prior-knowledge and --http3.
--http1.1
(HTTP) Tells curl to use HTTP version 1.1.
Providing --http1.1 multiple times has no extra effect.
Example:
curl --http1.1 https://example.com
See also -0, --http1.0 and --http0.9. This option is mutually exclusive
to -0, --http1.0 and --http2 and --http2-prior-knowledge and --http3.
--http2-prior-knowledge
(HTTP) Tells curl to issue its non-TLS HTTP requests using HTTP/2 with‐
out HTTP/1.1 Upgrade. It requires prior knowledge that the server sup‐
ports HTTP/2 straight away. HTTPS requests still do HTTP/2 the standard
way with negotiated protocol version in the TLS handshake.
Providing --http2-prior-knowledge multiple times has no extra effect.
Disable it again with --no-http2-prior-knowledge.
Example:
curl --http2-prior-knowledge https://example.com
See also --http2 and --http3. --http2-prior-knowledge requires that the
underlying libcurl was built to support HTTP/2. This option is mutually
exclusive to --http1.1 and -0, --http1.0 and --http2 and --http3.
--http2
(HTTP) Tells curl to use HTTP version 2.
For HTTPS, this means curl negotiates HTTP/2 in the TLS handshake. curl
does this by default.
For HTTP, this means curl attempts to upgrade the request to HTTP/2 us‐
ing the Upgrade: request header.
When curl uses HTTP/2 over HTTPS, it does not itself insist on TLS 1.2
or higher even though that is required by the specification. A user can
add this version requirement with --tlsv1.2.
Providing --http2 multiple times has no extra effect.
Example:
curl --http2 https://example.com
See also --http1.1, --http3 and --no-alpn. --http2 requires that the
underlying libcurl was built to support HTTP/2. This option is mutually
exclusive to --http1.1 and -0, --http1.0 and --http2-prior-knowledge
and --http3.
--http3-only
(HTTP) **WARNING**: this option is experimental. Do not use in produc‐
tion.
Instructs curl to use HTTP/3 to the host in the URL, with no fallback
to earlier HTTP versions. HTTP/3 can only be used for HTTPS and not for
HTTP URLs. For HTTP, this option triggers an error.
This option allows a user to avoid using the Alt-Svc method of upgrad‐
ing to HTTP/3 when you know that the target speaks HTTP/3 on the given
host and port.
This option makes curl fail if a QUIC connection cannot be established,
it does not attempt any other HTTP versions on its own. Use --http3 for
similar functionality with a fallback.
Providing --http3-only multiple times has no extra effect.
Example:
curl --http3-only https://example.com
See also --http1.1, --http2 and --http3. --http3-only requires that the
underlying libcurl was built to support HTTP/3. This option is mutually
exclusive to --http1.1 and -0, --http1.0 and --http2 and
--http2-prior-knowledge and --http3. Added in 7.88.0.
--http3
(HTTP) **WARNING**: this option is experimental. Do not use in produc‐
tion.
Tells curl to try HTTP/3 to the host in the URL, but fallback to ear‐
lier HTTP versions if the HTTP/3 connection establishment fails. HTTP/3
is only available for HTTPS and not for HTTP URLs.
This option allows a user to avoid using the Alt-Svc method of upgrad‐
ing to HTTP/3 when you know that the target speaks HTTP/3 on the given
host and port.
When asked to use HTTP/3, curl issues a separate attempt to use older
HTTP versions with a slight delay, so if the HTTP/3 transfer fails or
is slow, curl still tries to proceed with an older HTTP version.
Use --http3-only for similar functionality without a fallback.
Providing --http3 multiple times has no extra effect.
Example:
curl --http3 https://example.com
See also --http1.1 and --http2. --http3 requires that the underlying
libcurl was built to support HTTP/3. This option is mutually exclusive
to --http1.1 and -0, --http1.0 and --http2 and --http2-prior-knowledge
and --http3-only. Added in 7.66.0.
--ignore-content-length
(FTP HTTP) For HTTP, Ignore the Content-Length header. This is particu‐
larly useful for servers running Apache 1.x, which reports incorrect
Content-Length for files larger than 2 gigabytes.
For FTP, this makes curl skip the SIZE command to figure out the size
before downloading a file.
This option does not work for HTTP if libcurl was built to use hyper.
Providing --ignore-content-length multiple times has no extra effect.
Disable it again with --no-ignore-content-length.
Example:
curl --ignore-content-length https://example.com
See also --ftp-skip-pasv-ip.
-i, --include
Include the HTTP response headers in the output. The HTTP response
headers can include things like server name, cookies, date of the docu‐
ment, HTTP version and more...
To view the request headers, consider the -v, --verbose option.
Prior to 7.75.0 curl did not print the headers if -f, --fail was used
in combination with this option and there was error reported by server.
Providing -i, --include multiple times has no extra effect. Disable it
again with --no-include.
Example:
curl -i https://example.com
See also -v, --verbose.
-k, --insecure
(TLS SFTP SCP) By default, every secure connection curl makes is veri‐
fied to be secure before the transfer takes place. This option makes
curl skip the verification step and proceed without checking.
When this option is not used for protocols using TLS, curl verifies the
server's TLS certificate before it continues: that the certificate con‐
tains the right name which matches the host name used in the URL and
that the certificate has been signed by a CA certificate present in the
cert store. See this online resource for further details:
https://curl.se/docs/sslcerts.html
For SFTP and SCP, this option makes curl skip the known_hosts verifica‐
tion. known_hosts is a file normally stored in the user's home direc‐
tory in the ".ssh" subdirectory, which contains host names and their
public keys.
WARNING: using this option makes the transfer insecure.
When curl uses secure protocols it trusts responses and allows for ex‐
ample HSTS and Alt-Svc information to be stored and used subsequently.
Using -k, --insecure can make curl trust and use such information from
malicious servers.
Providing -k, --insecure multiple times has no extra effect. Disable
it again with --no-insecure.
Example:
curl --insecure https://example.com
See also --proxy-insecure, --cacert and --capath.
--interface <name>
Perform an operation using a specified interface. You can enter inter‐
face name, IP address or host name. An example could look like:
curl --interface eth0:1 https://www.example.com/
On Linux it can be used to specify a VRF, but the binary needs to ei‐
ther have CAP_NET_RAW or to be run as root. More information about
Linux VRF: https://www.kernel.org/doc/Documentation/networking/vrf.txt
If --interface is provided several times, the last set value is used.
Example:
curl --interface eth0 https://example.com
See also --dns-interface.
--ipfs-gateway <URL>
Specify which gateway to use for IPFS and IPNS URLs. Not specifying
this will instead make curl check if the IPFS_GATEWAY environment vari‐
able is set, or if a ~/.ipfs/gateway file holding the gateway URL ex‐
ists.
If you run a local IPFS node, this gateway is by default available un‐
der http://localhost:8080. A full example URL would look like:
curl --ipfs-gateway http://localhost:8080 ipfs://bafybeigagd5nmnn2iys2f3doro7ydrevyr2mzarwidgadawmamiteydbzi
There are many public IPFS gateways. See for example:
https://ipfs.github.io/public-gateway-checker/
WARNING: If you opt to go for a remote gateway you should be aware that
you completely trust the gateway. This is fine in local gateways as you
host it yourself. With remote gateways there could potentially be a ma‐
licious actor returning you data that does not match the request you
made, inspect or even interfere with the request. You will not notice
this when using curl. A mitigation could be to go for a "trustless"
gateway. This means you locally verify that the data. Consult the docs
page on trusted vs trustless: https://docs.ipfs.tech/refer‐
ence/http/gateway/#trusted-vs-trustless
If --ipfs-gateway is provided several times, the last set value is
used.
Example:
curl --ipfs-gateway https://example.com ipfs://
See also -h, --help and -M, --manual. Added in 8.4.0.
-4, --ipv4
This option tells curl to use IPv4 addresses only when resolving host
names, and not for example try IPv6.
Providing -4, --ipv4 multiple times has no extra effect.
Example:
curl --ipv4 https://example.com
See also --http1.1 and --http2. This option is mutually exclusive to
-6, --ipv6.
-6, --ipv6
This option tells curl to use IPv6 addresses only when resolving host
names, and not for example try IPv4.
Providing -6, --ipv6 multiple times has no extra effect.
Example:
curl --ipv6 https://example.com
See also --http1.1 and --http2. This option is mutually exclusive to
-4, --ipv4.
--json <data>
(HTTP) Sends the specified JSON data in a POST request to the HTTP
server. --json works as a shortcut for passing on these three options:
--data [arg]
--header "Content-Type: application/json"
--header "Accept: application/json"
There is no verification that the passed in data is actual JSON or that
the syntax is correct.
If you start the data with the letter @, the rest should be a file name
to read the data from, or a single dash (-) if you want curl to read
the data from stdin. Posting data from a file named 'foobar' would thus
be done with --json @foobar and to instead read the data from stdin,
use --json @-.
If this option is used more than once on the same command line, the ad‐
ditional data pieces are concatenated to the previous before sending.
The headers this option sets can be overridden with -H, --header as
usual.
--json can be used several times in a command line
Examples:
curl --json '{ "drink": "coffe" }' https://example.com
curl --json '{ "drink":' --json ' "coffe" }' https://example.com
curl --json @prepared https://example.com
curl --json @- https://example.com < json.txt
See also --data-binary and --data-raw. This option is mutually exclu‐
sive to -F, --form and -I, --head and -T, --upload-file. Added in
7.82.0.
-j, --junk-session-cookies
(HTTP) When curl is told to read cookies from a given file, this option
makes it discard all "session cookies". This has the same effect as if
a new session is started. Typical browsers discard session cookies when
they are closed down.
Providing -j, --junk-session-cookies multiple times has no extra ef‐
fect. Disable it again with --no-junk-session-cookies.
Example:
curl --junk-session-cookies -b cookies.txt https://example.com
See also -b, --cookie and -c, --cookie-jar.
--keepalive-time <seconds>
This option sets the time a connection needs to remain idle before
sending keepalive probes and the time between individual keepalive
probes. It is currently effective on operating systems offering the
TCP_KEEPIDLE and TCP_KEEPINTVL socket options (meaning Linux, recent
AIX, HP-UX and more). Keepalives are used by the TCP stack to detect
broken networks on idle connections. The number of missed keepalive
probes before declaring the connection down is OS dependent and is com‐
monly 9 or 10. This option has no effect if --no-keepalive is used.
If unspecified, the option defaults to 60 seconds.
If --keepalive-time is provided several times, the last set value is
used.
Example:
curl --keepalive-time 20 https://example.com
See also --no-keepalive and -m, --max-time.
--key-type <type>
(TLS) Private key file type. Specify which type your --key provided
private key is. DER, PEM, and ENG are supported. If not specified, PEM
is assumed.
If --key-type is provided several times, the last set value is used.
Example:
curl --key-type DER --key here https://example.com
See also --key.
--key <key>
(TLS SSH) Private key file name. Allows you to provide your private key
in this separate file. For SSH, if not specified, curl tries the fol‐
lowing candidates in order: '~/.ssh/id_rsa', '~/.ssh/id_dsa',
'./id_rsa', './id_dsa'.
If curl is built against OpenSSL library, and the engine pkcs11 is
available, then a PKCS#11 URI (RFC 7512) can be used to specify a pri‐
vate key located in a PKCS#11 device. A string beginning with "pkcs11:"
is interpreted as a PKCS#11 URI. If a PKCS#11 URI is provided, then the
--engine option is set as "pkcs11" if none was provided and the
--key-type option is set as "ENG" if none was provided.
If curl is built against Secure Transport or Schannel then this option
is ignored for TLS protocols (HTTPS, etc). Those backends expect the
private key to be already present in the keychain or PKCS#12 file con‐
taining the certificate.
If --key is provided several times, the last set value is used.
Example:
curl --cert certificate --key here https://example.com
See also --key-type and -E, --cert.
--krb <level>
(FTP) Enable Kerberos authentication and use. The level must be entered
and should be one of 'clear', 'safe', 'confidential', or 'private'.
Should you use a level that is not one of these, 'private' is used.
If --krb is provided several times, the last set value is used.
Example:
curl --krb clear ftp://example.com/
See also --delegation and --ssl. --krb requires that the underlying
libcurl was built to support Kerberos.
--libcurl <file>
Append this option to any ordinary curl command line, and you get
libcurl-using C source code written to the file that does the equiva‐
lent of what your command-line operation does!
This option is global and does not need to be specified for each use of
--next.
If --libcurl is provided several times, the last set value is used.
Example:
curl --libcurl client.c https://example.com
See also -v, --verbose.
--limit-rate <speed>
Specify the maximum transfer rate you want curl to use - for both down‐
loads and uploads. This feature is useful if you have a limited pipe
and you would like your transfer not to use your entire bandwidth. To
make it slower than it otherwise would be.
The given speed is measured in bytes/second, unless a suffix is ap‐
pended. Appending 'k' or 'K' counts the number as kilobytes, 'm' or
'M' makes it megabytes, while 'g' or 'G' makes it gigabytes. The suf‐
fixes (k, M, G, T, P) are 1024 based. For example 1k is 1024. Examples:
200K, 3m and 1G.
The rate limiting logic works on averaging the transfer speed to no
more than the set threshold over a period of multiple seconds.
If you also use the -Y, --speed-limit option, that option takes prece‐
dence and might cripple the rate-limiting slightly, to help keeping the
speed-limit logic working.
If --limit-rate is provided several times, the last set value is used.
Examples:
curl --limit-rate 100K https://example.com
curl --limit-rate 1000 https://example.com
curl --limit-rate 10M https://example.com
See also --rate, -Y, --speed-limit and -y, --speed-time.
-l, --list-only
(FTP POP3 SFTP) (FTP) When listing an FTP directory, this switch forces
a name-only view. This is especially useful if the user wants to ma‐
chine-parse the contents of an FTP directory since the normal directory
view does not use a standard look or format. When used like this, the
option causes an NLST command to be sent to the server instead of LIST.
Note: Some FTP servers list only files in their response to NLST; they
do not include sub-directories and symbolic links.
(SFTP) When listing an SFTP directory, this switch forces a name-only
view, one per line. This is especially useful if the user wants to ma‐
chine-parse the contents of an SFTP directory since the normal direc‐
tory view provides more information than just file names.
(POP3) When retrieving a specific email from POP3, this switch forces a
LIST command to be performed instead of RETR. This is particularly use‐
ful if the user wants to see if a specific message-id exists on the
server and what size it is.
Note: When combined with -X, --request, this option can be used to send
a UIDL command instead, so the user may use the email's unique identi‐
fier rather than its message-id to make the request.
Providing -l, --list-only multiple times has no extra effect. Disable
it again with --no-list-only.
Example:
curl --list-only ftp://example.com/dir/
See also -Q, --quote and -X, --request.
--local-port <num/range>
Set a preferred single number or range (FROM-TO) of local port numbers
to use for the connection(s). Note that port numbers by nature are a
scarce resource so setting this range to something too narrow might
cause unnecessary connection setup failures.
If --local-port is provided several times, the last set value is used.
Example:
curl --local-port 1000-3000 https://example.com
See also -g, --globoff.
--location-trusted
(HTTP) Like -L, --location, but allows sending the name + password to
all hosts that the site may redirect to. This may or may not introduce
a security breach if the site redirects you to a site to which you send
your authentication info (which is plaintext in the case of HTTP Basic
authentication).
Providing --location-trusted multiple times has no extra effect. Dis‐
able it again with --no-location-trusted.
Example:
curl --location-trusted -u user:password https://example.com
See also -u, --user.
-L, --location
(HTTP) If the server reports that the requested page has moved to a
different location (indicated with a Location: header and a 3XX re‐
sponse code), this option makes curl redo the request on the new place.
If used together with -i, --include or -I, --head, headers from all re‐
quested pages are shown.
When authentication is used, curl only sends its credentials to the
initial host. If a redirect takes curl to a different host, it does not
get the user+password pass on. See also --location-trusted on how to
change this.
Limit the amount of redirects to follow by using the --max-redirs op‐
tion.
When curl follows a redirect and if the request is a POST, it sends the
following request with a GET if the HTTP response was 301, 302, or 303.
If the response code was any other 3xx code, curl resends the following
request using the same unmodified method.
You can tell curl to not change POST requests to GET after a 30x re‐
sponse by using the dedicated options for that: --post301, --post302
and --post303.
The method set with -X, --request overrides the method curl would oth‐
erwise select to use.
Providing -L, --location multiple times has no extra effect. Disable
it again with --no-location.
Example:
curl -L https://example.com
See also --resolve and --alt-svc.
--login-options <options>
(IMAP LDAP POP3 SMTP) Specify the login options to use during server
authentication.
You can use login options to specify protocol specific options that may
be used during authentication. At present only IMAP, POP3 and SMTP sup‐
port login options. For more information about login options please see
RFC 2384, RFC 5092 and the IETF draft https://data‐
tracker.ietf.org/doc/html/draft-earhart-url-smtp-00.
Since 8.2.0, IMAP supports the login option "AUTH=+LOGIN". With this
option, curl uses the plain (not SASL) LOGIN IMAP command even if the
server advertises SASL authentication. Care should be taken in using
this option, as it sends your password over the network in plain text.
This does not work if the IMAP server disables the plain LOGIN (e.g. to
prevent password snooping).
If --login-options is provided several times, the last set value is
used.
Example:
curl --login-options 'AUTH=*' imap://example.com
See also -u, --user.
--mail-auth <address>
(SMTP) Specify a single address. This is used to specify the authenti‐
cation address (identity) of a submitted message that is being relayed
to another server.
If --mail-auth is provided several times, the last set value is used.
Example:
curl --mail-auth user@example.come -T mail smtp://example.com/
See also --mail-rcpt and --mail-from.
--mail-from <address>
(SMTP) Specify a single address that the given mail should get sent
from.
If --mail-from is provided several times, the last set value is used.
Example:
curl --mail-from user@example.com -T mail smtp://example.com/
See also --mail-rcpt and --mail-auth.
--mail-rcpt-allowfails
(SMTP) When sending data to multiple recipients, by default curl aborts
SMTP conversation if at least one of the recipients causes RCPT TO com‐
mand to return an error.
The default behavior can be changed by passing --mail-rcpt-allowfails
command-line option which makes curl ignore errors and proceed with the
remaining valid recipients.
If all recipients trigger RCPT TO failures and this flag is specified,
curl still aborts the SMTP conversation and returns the error received
from to the last RCPT TO command.
Providing --mail-rcpt-allowfails multiple times has no extra effect.
Disable it again with --no-mail-rcpt-allowfails.
Example:
curl --mail-rcpt-allowfails --mail-rcpt dest@example.com smtp://example.com
See also --mail-rcpt. Added in 7.69.0.
--mail-rcpt <address>
(SMTP) Specify a single email address, user name or mailing list name.
Repeat this option several times to send to multiple recipients.
When performing an address verification (VRFY command), the recipient
should be specified as the user name or user name and domain (as per
Section 3.5 of RFC 5321).
When performing a mailing list expand (EXPN command), the recipient
should be specified using the mailing list name, such as "Friends" or
"London-Office".
--mail-rcpt can be used several times in a command line
Example:
curl --mail-rcpt user@example.net smtp://example.com
See also --mail-rcpt-allowfails.
-M, --manual
Manual. Display the huge help text.
Example:
curl --manual
See also -v, --verbose, --libcurl and --trace.
--max-filesize <bytes>
(FTP HTTP MQTT) Specify the maximum size (in bytes) of a file to down‐
load. If the file requested is larger than this value, the transfer
does not start and curl returns with exit code 63.
A size modifier may be used. For example, Appending 'k' or 'K' counts
the number as kilobytes, 'm' or 'M' makes it megabytes, while 'g' or
'G' makes it gigabytes. Examples: 200K, 3m and 1G. (Added in 7.58.0)
NOTE: before curl 8.4.0, when the file size is not known prior to down‐
load, for such files this option has no effect even if the file trans‐
fer ends up being larger than this given limit.
Starting with curl 8.4.0, this option aborts the transfer if it reaches
the threshold during transfer.
If --max-filesize is provided several times, the last set value is
used.
Example:
curl --max-filesize 100K https://example.com
See also --limit-rate.
--max-redirs <num>
(HTTP) Set maximum number of redirections to follow. When -L, --loca‐
tion is used, to prevent curl from following too many redirects, by de‐
fault, the limit is set to 50 redirects. Set this option to -1 to make
it unlimited.
If --max-redirs is provided several times, the last set value is used.
Example:
curl --max-redirs 3 --location https://example.com
See also -L, --location.
-m, --max-time <fractional seconds>
Maximum time in seconds that you allow each transfer to take. This is
useful for preventing your batch jobs from hanging for hours due to
slow networks or links going down. This option accepts decimal values.
If you enable retrying the transfer (--retry) then the maximum time
counter is reset each time the transfer is retried. You can use
--retry-max-time to limit the retry time.
The decimal value needs to provided using a dot (.) as decimal separa‐
tor - not the local version even if it might be using another separa‐
tor.
If -m, --max-time is provided several times, the last set value is
used.
Examples:
curl --max-time 10 https://example.com
curl --max-time 2.92 https://example.com
See also --connect-timeout and --retry-max-time.
--metalink
This option was previously used to specify a Metalink resource. Met‐
alink support is disabled in curl for security reasons (added in
7.78.0).
If --metalink is provided several times, the last set value is used.
Example:
curl --metalink file https://example.com
See also -Z, --parallel.
--negotiate
(HTTP) Enables Negotiate (SPNEGO) authentication.
This option requires a library built with GSS-API or SSPI support. Use
-V, --version to see if your curl supports GSS-API/SSPI or SPNEGO.
When using this option, you must also provide a fake -u, --user option
to activate the authentication code properly. Sending a '-u :' is
enough as the user name and password from the -u, --user option are not
actually used.
Providing --negotiate multiple times has no extra effect.
Example:
curl --negotiate -u : https://example.com
See also --basic, --ntlm, --anyauth and --proxy-negotiate.
--netrc-file <filename>
This option is similar to -n, --netrc, except that you provide the path
(absolute or relative) to the netrc file that curl should use. You can
only specify one netrc file per invocation.
It abides by --netrc-optional if specified.
If --netrc-file is provided several times, the last set value is used.
Example:
curl --netrc-file netrc https://example.com
See also -n, --netrc, -u, --user and -K, --config. This option is mutu‐
ally exclusive to -n, --netrc.
--netrc-optional
Similar to -n, --netrc, but this option makes the .netrc usage optional
and not mandatory as the -n, --netrc option does.
Providing --netrc-optional multiple times has no extra effect. Disable
it again with --no-netrc-optional.
Example:
curl --netrc-optional https://example.com
See also --netrc-file. This option is mutually exclusive to -n,
--netrc.
-n, --netrc
Makes curl scan the .netrc file in the user's home directory for login
name and password. This is typically used for FTP on Unix. If used with
HTTP, curl enables user authentication. See netrc(5) and ftp(1) for de‐
tails on the file format. Curl does not complain if that file does not
have the right permissions (it should be neither world- nor group-read‐
able). The environment variable "HOME" is used to find the home direc‐
tory.
On Windows two filenames in the home directory are checked: .netrc and
_netrc, preferring the former. Older versions on Windows checked for
_netrc only.
A quick and simple example of how to setup a .netrc to allow curl to
FTP to the machine host.domain.com with user name 'myself' and password
'secret' could look similar to:
machine host.domain.com
login myself
password secret
Providing -n, --netrc multiple times has no extra effect. Disable it
again with --no-netrc.
Example:
curl --netrc https://example.com
See also --netrc-file, -K, --config and -u, --user. This option is mu‐
tually exclusive to --netrc-file and --netrc-optional.
-:, --next
Tells curl to use a separate operation for the following URL and asso‐
ciated options. This allows you to send several URL requests, each with
their own specific options, for example, such as different user names
or custom requests for each.
-:, --next resets all local options and only global ones have their
values survive over to the operation following the -:, --next instruc‐
tion. Global options include -v, --verbose, --trace, --trace-ascii and
--fail-early.
For example, you can do both a GET and a POST in a single command line:
curl www1.example.com --next -d postthis www2.example.com
-:, --next can be used several times in a command line
Examples:
curl https://example.com --next -d postthis www2.example.com
curl -I https://example.com --next https://example.net/
See also -Z, --parallel and -K, --config.
--no-alpn
(HTTPS) Disable the ALPN TLS extension. ALPN is enabled by default if
libcurl was built with an SSL library that supports ALPN. ALPN is used
by a libcurl that supports HTTP/2 to negotiate HTTP/2 support with the
server during https sessions.
Note that this is the negated option name documented. You can use
--alpn to enable ALPN.
Providing --no-alpn multiple times has no extra effect. Disable it
again with --alpn.
Example:
curl --no-alpn https://example.com
See also --no-npn and --http2. --no-alpn requires that the underlying
libcurl was built to support TLS.
-N, --no-buffer
Disables the buffering of the output stream. In normal work situations,
curl uses a standard buffered output stream that has the effect that it
outputs the data in chunks, not necessarily exactly when the data ar‐
rives. Using this option disables that buffering.
Note that this is the negated option name documented. You can use
--buffer to enable buffering again.
Providing -N, --no-buffer multiple times has no extra effect. Disable
it again with --buffer.
Example:
curl --no-buffer https://example.com
See also -#, --progress-bar.
--no-clobber
When used in conjunction with the -o, --output, -J, --re‐
mote-header-name, -O, --remote-name, or --remote-name-all options, curl
avoids overwriting files that already exist. Instead, a dot and a num‐
ber gets appended to the name of the file that would be created, up to
filename.100 after which it does not create any file.
Note that this is the negated option name documented. You can thus use
--clobber to enforce the clobbering, even if -J, --remote-header-name
is specified.
Providing --no-clobber multiple times has no extra effect. Disable it
again with --clobber.
Example:
curl --no-clobber --output local/dir/file https://example.com
See also -o, --output and -O, --remote-name. Added in 7.83.0.
--no-keepalive
Disables the use of keepalive messages on the TCP connection. curl oth‐
erwise enables them by default.
Note that this is the negated option name documented. You can thus use
--keepalive to enforce keepalive.
Providing --no-keepalive multiple times has no extra effect. Disable
it again with --keepalive.
Example:
curl --no-keepalive https://example.com
See also --keepalive-time.
--no-npn
(HTTPS) curl never uses NPN, this option has no effect (added in
7.86.0).
Disable the NPN TLS extension. NPN is enabled by default if libcurl was
built with an SSL library that supports NPN. NPN is used by a libcurl
that supports HTTP/2 to negotiate HTTP/2 support with the server during
https sessions.
Providing --no-npn multiple times has no extra effect. Disable it
again with --npn.
Example:
curl --no-npn https://example.com
See also --no-alpn and --http2. --no-npn requires that the underlying
libcurl was built to support TLS.
--no-progress-meter
Option to switch off the progress meter output without muting or other‐
wise affecting warning and informational messages like -s, --silent
does.
Note that this is the negated option name documented. You can thus use
--progress-meter to enable the progress meter again.
Providing --no-progress-meter multiple times has no extra effect. Dis‐
able it again with --progress-meter.
Example:
curl --no-progress-meter -o store https://example.com
See also -v, --verbose and -s, --silent. Added in 7.67.0.
--no-sessionid
(TLS) Disable curl's use of SSL session-ID caching. By default all
transfers are done using the cache. Note that while nothing should ever
get hurt by attempting to reuse SSL session-IDs, there seem to be bro‐
ken SSL implementations in the wild that may require you to disable
this in order for you to succeed.
Note that this is the negated option name documented. You can thus use
--sessionid to enforce session-ID caching.
Providing --no-sessionid multiple times has no extra effect. Disable
it again with --sessionid.
Example:
curl --no-sessionid https://example.com
See also -k, --insecure.
--noproxy <no-proxy-list>
Comma-separated list of hosts for which not to use a proxy, if one is
specified. The only wildcard is a single * character, which matches all
hosts, and effectively disables the proxy. Each name in this list is
matched as either a domain which contains the hostname, or the hostname
itself. For example, local.com would match local.com, local.com:80, and
www.local.com, but not www.notlocal.com.
This option overrides the environment variables that disable the proxy
('no_proxy' and 'NO_PROXY') (added in 7.53.0). If there is an environ‐
ment variable disabling a proxy, you can set the no proxy list to "" to
override it.
IP addresses specified to this option can be provided using CIDR nota‐
tion (added in 7.86.0): an appended slash and number specifies the num‐
ber of "network bits" out of the address to use in the comparison. For
example "192.168.0.0/16" would match all addresses starting with
"192.168".
If --noproxy is provided several times, the last set value is used.
Example:
curl --noproxy "www.example" https://example.com
See also -x, --proxy.
--ntlm-wb
(HTTP) Enables NTLM much in the style --ntlm does, but hand over the
authentication to the separate binary ntlmauth application that is exe‐
cuted when needed.
Providing --ntlm-wb multiple times has no extra effect.
Example:
curl --ntlm-wb -u user:password https://example.com
See also --ntlm and --proxy-ntlm.
--ntlm (HTTP) Enables NTLM authentication. The NTLM authentication method was
designed by Microsoft and is used by IIS web servers. It is a propri‐
etary protocol, reverse-engineered by clever people and implemented in
curl based on their efforts. This kind of behavior should not be en‐
dorsed, you should encourage everyone who uses NTLM to switch to a pub‐
lic and documented authentication method instead, such as Digest.
If you want to enable NTLM for your proxy authentication, then use
--proxy-ntlm.
Providing --ntlm multiple times has no extra effect.
Example:
curl --ntlm -u user:password https://example.com
See also --proxy-ntlm. --ntlm requires that the underlying libcurl was
built to support TLS. This option is mutually exclusive to --basic and
--negotiate and --digest and --anyauth.
--oauth2-bearer <token>
(IMAP LDAP POP3 SMTP HTTP) Specify the Bearer Token for OAUTH 2.0
server authentication. The Bearer Token is used in conjunction with the
user name which can be specified as part of the --url or -u, --user op‐
tions.
The Bearer Token and user name are formatted according to RFC 6750.
If --oauth2-bearer is provided several times, the last set value is
used.
Example:
curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com
See also --basic, --ntlm and --digest.
--output-dir <dir>
This option specifies the directory in which files should be stored,
when -O, --remote-name or -o, --output are used.
The given output directory is used for all URLs and output options on
the command line, up until the first -:, --next.
If the specified target directory does not exist, the operation fails
unless --create-dirs is also used.
If --output-dir is provided several times, the last set value is used.
Example:
curl --output-dir "tmp" -O https://example.com
See also -O, --remote-name and -J, --remote-header-name. Added in
7.73.0.
-o, --output <file>
Write output to <file> instead of stdout. If you are using {} or [] to
fetch multiple documents, you should quote the URL and you can use '#'
followed by a number in the <file> specifier. That variable is replaced
with the current string for the URL being fetched. Like in:
curl "http://{one,two}.example.com" -o "file_#1.txt"
or use several variables like:
curl "http://{site,host}.host[1-5].example" -o "#1_#2"
You may use this option as many times as the number of URLs you have.
For example, if you specify two URLs on the same command line, you can
use it like this:
curl -o aa example.com -o bb example.net
and the order of the -o options and the URLs does not matter, just that
the first -o is for the first URL and so on, so the above command line
can also be written as
curl example.com example.net -o aa -o bb
See also the --create-dirs option to create the local directories dy‐
namically. Specifying the output as '-' (a single dash) passes the out‐
put to stdout.
To suppress response bodies, you can redirect output to /dev/null:
curl example.com -o /dev/null
Or for Windows:
curl example.com -o nul
-o, --output can be used several times in a command line
Examples:
curl -o file https://example.com
curl "http://{one,two}.example.com" -o "file_#1.txt"
curl "http://{site,host}.host[1-5].example" -o "#1_#2"
curl -o file https://example.com -o file2 https://example.net
See also -O, --remote-name, --remote-name-all and -J, --re‐
mote-header-name.
--parallel-immediate
When doing parallel transfers, this option instructs curl that it
should rather prefer opening up more connections in parallel at once
rather than waiting to see if new transfers can be added as multiplexed
streams on another connection.
This option is global and does not need to be specified for each use of
--next.
Providing --parallel-immediate multiple times has no extra effect.
Disable it again with --no-parallel-immediate.
Example:
curl --parallel-immediate -Z https://example.com -o file1 https://example.com -o file2
See also -Z, --parallel and --parallel-max. Added in 7.68.0.
--parallel-max <num>
When asked to do parallel transfers, using -Z, --parallel, this option
controls the maximum amount of transfers to do simultaneously.
This option is global and does not need to be specified for each use of
-:, --next.
The default is 50.
If --parallel-max is provided several times, the last set value is
used.
Example:
curl --parallel-max 100 -Z https://example.com ftp://example.com/
See also -Z, --parallel. Added in 7.66.0.
-Z, --parallel
Makes curl perform its transfers in parallel as compared to the regular
serial manner.
This option is global and does not need to be specified for each use of
--next.
Providing -Z, --parallel multiple times has no extra effect. Disable
it again with --no-parallel.
Example:
curl --parallel https://example.com -o file1 https://example.com -o file2
See also -:, --next and -v, --verbose. Added in 7.66.0.
--pass <phrase>
(SSH TLS) Passphrase for the private key.
If --pass is provided several times, the last set value is used.
Example:
curl --pass secret --key file https://example.com
See also --key and -u, --user.
--path-as-is
Tell curl to not handle sequences of /../ or /./ in the given URL path.
Normally curl squashes or merges them according to standards but with
this option set you tell it not to do that.
Providing --path-as-is multiple times has no extra effect. Disable it
again with --no-path-as-is.
Example:
curl --path-as-is https://example.com/../../etc/passwd
See also --request-target.
--pinnedpubkey <hashes>
(TLS) Tells curl to use the specified public key file (or hashes) to
verify the peer. This can be a path to a file which contains a single
public key in PEM or DER format, or any number of base64 encoded sha256
hashes preceded by 'sha256//' and separated by ';'.
When negotiating a TLS or SSL connection, the server sends a certifi‐
cate indicating its identity. A public key is extracted from this cer‐
tificate and if it does not exactly match the public key provided to
this option, curl aborts the connection before sending or receiving any
data.
This option is independent of option -k, --insecure. If you use both
options together then the peer is still verified by public key.
PEM/DER support:
OpenSSL and GnuTLS, wolfSSL (added in 7.43.0), mbedTLS , Secure Trans‐
port macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1)
sha256 support:
OpenSSL, GnuTLS and wolfSSL, mbedTLS (added in 7.47.0), Secure Trans‐
port macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1)
Other SSL backends not supported.
If --pinnedpubkey is provided several times, the last set value is
used.
Examples:
curl --pinnedpubkey keyfile https://example.com
curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --hostpubsha256.
--post301
(HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST re‐
quests into GET requests when following a 301 redirection. The non-RFC
behavior is ubiquitous in web browsers, so curl does the conversion by
default to maintain consistency. However, a server may require a POST
to remain a POST after such a redirection. This option is meaningful
only when using -L, --location.
Providing --post301 multiple times has no extra effect. Disable it
again with --no-post301.
Example:
curl --post301 --location -d "data" https://example.com
See also --post302, --post303 and -L, --location.
--post302
(HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST re‐
quests into GET requests when following a 302 redirection. The non-RFC
behavior is ubiquitous in web browsers, so curl does the conversion by
default to maintain consistency. However, a server may require a POST
to remain a POST after such a redirection. This option is meaningful
only when using -L, --location.
Providing --post302 multiple times has no extra effect. Disable it
again with --no-post302.
Example:
curl --post302 --location -d "data" https://example.com
See also --post301, --post303 and -L, --location.
--post303
(HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST re‐
quests into GET requests when following 303 redirections. A server may
require a POST to remain a POST after a 303 redirection. This option is
meaningful only when using -L, --location.
Providing --post303 multiple times has no extra effect. Disable it
again with --no-post303.
Example:
curl --post303 --location -d "data" https://example.com
See also --post302, --post301 and -L, --location.
--preproxy [protocol://]host[:port]
Use the specified SOCKS proxy before connecting to an HTTP or HTTPS -x,
--proxy. In such a case curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy. Hence pre proxy.
The pre proxy string should be specified with a protocol:// prefix to
specify alternative proxy protocols. Use socks4://, socks4a://,
socks5:// or socks5h:// to request the specific SOCKS version to be
used. No protocol specified makes curl default to SOCKS4.
If the port number is not specified in the proxy string, it is assumed
to be 1080.
User and password that might be provided in the proxy string are URL
decoded by curl. This allows you to pass in special characters such as
@ by using %40 or pass in a colon with %3a.
If --preproxy is provided several times, the last set value is used.
Example:
curl --preproxy socks5://proxy.example -x http://http.example https://example.com
See also -x, --proxy and --socks5. Added in 7.52.0.
-#, --progress-bar
Make curl display transfer progress as a simple progress bar instead of
the standard, more informational, meter.
This progress bar draws a single line of '#' characters across the
screen and shows a percentage if the transfer size is known. For trans‐
fers without a known size, there is a space ship (-=o=-) that moves
back and forth but only while data is being transferred, with a set of
flying hash sign symbols on top.
This option is global and does not need to be specified for each use of
--next.
Providing -#, --progress-bar multiple times has no extra effect. Dis‐
able it again with --no-progress-bar.
Example:
curl -# -O https://example.com
See also --styled-output.
--proto-default <protocol>
Tells curl to use protocol for any URL missing a scheme name.
An unknown or unsupported protocol causes error CURLE_UNSUPPORTED_PRO‐
TOCOL (1).
This option does not change the default proxy protocol (http).
Without this option set, curl guesses protocol based on the host name,
see --url for details.
If --proto-default is provided several times, the last set value is
used.
Example:
curl --proto-default https ftp.example.com
See also --proto and --proto-redir.
--proto-redir <protocols>
Tells curl to limit what protocols it may use on redirect. Protocols
denied by --proto are not overridden by this option. See --proto for
how protocols are represented.
Example, allow only HTTP and HTTPS on redirect:
curl --proto-redir -all,http,https http://example.com
By default curl only allows HTTP, HTTPS, FTP and FTPS on redirects
(added in 7.65.2). Specifying all or +all enables all protocols on
redirects, which is not good for security.
If --proto-redir is provided several times, the last set value is used.
Example:
curl --proto-redir =http,https https://example.com
See also --proto.
--proto <protocols>
Tells curl to limit what protocols it may use for transfers. Protocols
are evaluated left to right, are comma separated, and are each a proto‐
col name or 'all', optionally prefixed by zero or more modifiers.
Available modifiers are:
+ Permit this protocol in addition to protocols already permitted
(this is the default if no modifier is used).
- Deny this protocol, removing it from the list of protocols already
permitted.
= Permit only this protocol (ignoring the list already permitted),
though subject to later modification by subsequent entries in the
comma separated list.
For example:
--proto -ftps uses the default protocols, but disables ftps
--proto -all,https,+http
only enables http and https
--proto =http,https
also only enables http and https
Unknown and disabled protocols produce a warning. This allows scripts
to safely rely on being able to disable potentially dangerous proto‐
cols, without relying upon support for that protocol being built into
curl to avoid an error.
This option can be used multiple times, in which case the effect is the
same as concatenating the protocols into one instance of the option.
If --proto is provided several times, the last set value is used.
Example:
curl --proto =http,https,sftp https://example.com
See also --proto-redir and --proto-default.
--proxy-anyauth
Tells curl to pick a suitable authentication method when communicating
with the given HTTP proxy. This might cause an extra request/response
round-trip.
Providing --proxy-anyauth multiple times has no extra effect.
Example:
curl --proxy-anyauth --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-basic and --proxy-digest.
--proxy-basic
Tells curl to use HTTP Basic authentication when communicating with the
given proxy. Use --basic for enabling HTTP Basic with a remote host.
Basic is the default authentication method curl uses with proxies.
Providing --proxy-basic multiple times has no extra effect.
Example:
curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-digest.
--proxy-ca-native
(TLS) Tells curl to use the CA store from the native operating system
to verify the HTTPS proxy. By default, curl uses a CA store provided in
a single file or directory, but when using this option it interfaces
the operating system's own vault.
This option only works for curl on Windows when built to use OpenSSL.
When curl on Windows is built to use Schannel, this feature is implied
and curl then only uses the native CA store.
curl built with wolfSSL also supports this option (added in 8.3.0).
Providing --proxy-ca-native multiple times has no extra effect. Dis‐
able it again with --no-proxy-ca-native.
Example:
curl --ca-native https://example.com
See also --cacert, --capath and -k, --insecure. Added in 8.2.0.
--proxy-cacert <file>
Same as --cacert but used in HTTPS proxy context.
If --proxy-cacert is provided several times, the last set value is
used.
Example:
curl --proxy-cacert CA-file.txt -x https://proxy https://example.com
See also --proxy-capath, --cacert, --capath and -x, --proxy. Added in
7.52.0.
--proxy-capath <dir>
Same as --capath but used in HTTPS proxy context.
If --proxy-capath is provided several times, the last set value is
used.
Example:
curl --proxy-capath /local/directory -x https://proxy https://example.com
See also --proxy-cacert, -x, --proxy and --capath. Added in 7.52.0.
--proxy-cert-type <type>
Same as --cert-type but used in HTTPS proxy context.
If --proxy-cert-type is provided several times, the last set value is
used.
Example:
curl --proxy-cert-type PEM --proxy-cert file -x https://proxy https://example.com
See also --proxy-cert. Added in 7.52.0.
--proxy-cert <cert[:passwd]>
Same as -E, --cert but used in HTTPS proxy context.
If --proxy-cert is provided several times, the last set value is used.
Example:
curl --proxy-cert file -x https://proxy https://example.com
See also --proxy-cert-type. Added in 7.52.0.
--proxy-ciphers <list>
Same as --ciphers but used in HTTPS proxy context.
Specifies which ciphers to use in the connection to the HTTPS proxy.
The list of ciphers must specify valid ciphers. Read up on SSL cipher
list details on this URL:
https://curl.se/docs/ssl-ciphers.html
If --proxy-ciphers is provided several times, the last set value is
used.
Example:
curl --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x https://proxy https://example.com
See also --ciphers, --curves and -x, --proxy. Added in 7.52.0.
--proxy-crlfile <file>
Same as --crlfile but used in HTTPS proxy context.
If --proxy-crlfile is provided several times, the last set value is
used.
Example:
curl --proxy-crlfile rejects.txt -x https://proxy https://example.com
See also --crlfile and -x, --proxy. Added in 7.52.0.
--proxy-digest
Tells curl to use HTTP Digest authentication when communicating with
the given proxy. Use --digest for enabling HTTP Digest with a remote
host.
Providing --proxy-digest multiple times has no extra effect.
Example:
curl --proxy-digest --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-basic.
--proxy-header <header/@file>
(HTTP) Extra header to include in the request when sending HTTP to a
proxy. You may specify any number of extra headers. This is the equiva‐
lent option to -H, --header but is for proxy communication only like in
CONNECT requests when you want a separate header sent to the proxy to
what is sent to the actual remote host.
curl makes sure that each header you add/replace is sent with the
proper end-of-line marker, you should thus not add that as a part of
the header content: do not add newlines or carriage returns, they only
mess things up for you.
Headers specified with this option are not included in requests that
curl knows are not be sent to a proxy.
This option can take an argument in @filename style, which then adds a
header for each line in the input file (added in 7.55.0). Using @-
makes curl read the headers from stdin.
This option can be used multiple times to add/replace/remove multiple
headers.
--proxy-header can be used several times in a command line
Examples:
curl --proxy-header "X-First-Name: Joe" -x http://proxy https://example.com
curl --proxy-header "User-Agent: surprise" -x http://proxy https://example.com
curl --proxy-header "Host:" -x http://proxy https://example.com
See also -x, --proxy.
--proxy-http2
(HTTP) Tells curl to try negotiate HTTP version 2 with an HTTPS proxy.
The proxy might still only offer HTTP/1 and then curl sticks to using
that version.
This has no effect for any other kinds of proxies.
Providing --proxy-http2 multiple times has no extra effect. Disable it
again with --no-proxy-http2.
Example:
curl --proxy-http2 -x proxy https://example.com
See also -x, --proxy. --proxy-http2 requires that the underlying
libcurl was built to support HTTP/2. Added in 8.1.0.
--proxy-insecure
Same as -k, --insecure but used in HTTPS proxy context.
Providing --proxy-insecure multiple times has no extra effect. Disable
it again with --no-proxy-insecure.
Example:
curl --proxy-insecure -x https://proxy https://example.com
See also -x, --proxy and -k, --insecure. Added in 7.52.0.
--proxy-key-type <type>
Same as --key-type but used in HTTPS proxy context.
If --proxy-key-type is provided several times, the last set value is
used.
Example:
curl --proxy-key-type DER --proxy-key here -x https://proxy https://example.com
See also --proxy-key and -x, --proxy. Added in 7.52.0.
--proxy-key <key>
Same as --key but used in HTTPS proxy context.
If --proxy-key is provided several times, the last set value is used.
Example:
curl --proxy-key here -x https://proxy https://example.com
See also --proxy-key-type and -x, --proxy. Added in 7.52.0.
--proxy-negotiate
Tells curl to use HTTP Negotiate (SPNEGO) authentication when communi‐
cating with the given proxy. Use --negotiate for enabling HTTP Negoti‐
ate (SPNEGO) with a remote host.
Providing --proxy-negotiate multiple times has no extra effect.
Example:
curl --proxy-negotiate --proxy-user user:passwd -x proxy https://example.com
See also --proxy-anyauth and --proxy-basic.
--proxy-ntlm
Tells curl to use HTTP NTLM authentication when communicating with the
given proxy. Use --ntlm for enabling NTLM with a remote host.
Providing --proxy-ntlm multiple times has no extra effect.
Example:
curl --proxy-ntlm --proxy-user user:passwd -x http://proxy https://example.com
See also --proxy-negotiate and --proxy-anyauth.
--proxy-pass <phrase>
Same as --pass but used in HTTPS proxy context.
If --proxy-pass is provided several times, the last set value is used.
Example:
curl --proxy-pass secret --proxy-key here -x https://proxy https://example.com
See also -x, --proxy and --proxy-key. Added in 7.52.0.
--proxy-pinnedpubkey <hashes>
(TLS) Tells curl to use the specified public key file (or hashes) to
verify the proxy. This can be a path to a file which contains a single
public key in PEM or DER format, or any number of base64 encoded sha256
hashes preceded by 'sha256//' and separated by ';'.
When negotiating a TLS or SSL connection, the server sends a certifi‐
cate indicating its identity. A public key is extracted from this cer‐
tificate and if it does not exactly match the public key provided to
this option, curl aborts the connection before sending or receiving any
data.
If --proxy-pinnedpubkey is provided several times, the last set value
is used.
Examples:
curl --proxy-pinnedpubkey keyfile https://example.com
curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --pinnedpubkey and -x, --proxy. Added in 7.59.0.
--proxy-service-name <name>
This option allows you to change the service name for proxy negotia‐
tion.
If --proxy-service-name is provided several times, the last set value
is used.
Example:
curl --proxy-service-name "shrubbery" -x proxy https://example.com
See also --service-name and -x, --proxy.
--proxy-ssl-allow-beast
Same as --ssl-allow-beast but used in HTTPS proxy context.
Providing --proxy-ssl-allow-beast multiple times has no extra effect.
Disable it again with --no-proxy-ssl-allow-beast.
Example:
curl --proxy-ssl-allow-beast -x https://proxy https://example.com
See also --ssl-allow-beast and -x, --proxy. Added in 7.52.0.
--proxy-ssl-auto-client-cert
Same as --ssl-auto-client-cert but used in HTTPS proxy context.
Providing --proxy-ssl-auto-client-cert multiple times has no extra ef‐
fect. Disable it again with --no-proxy-ssl-auto-client-cert.
Example:
curl --proxy-ssl-auto-client-cert -x https://proxy https://example.com
See also --ssl-auto-client-cert and -x, --proxy. Added in 7.77.0.
--proxy-tls13-ciphers <ciphersuite list>
(TLS) Specifies which cipher suites to use in the connection to your
HTTPS proxy when it negotiates TLS 1.3. The list of ciphers suites must
specify valid ciphers. Read up on TLS 1.3 cipher suite details on this
URL:
https://curl.se/docs/ssl-ciphers.html
This option is currently used only when curl is built to use OpenSSL
1.1.1 or later. If you are using a different SSL backend you can try
setting TLS 1.3 cipher suites by using the --proxy-ciphers option.
If --proxy-tls13-ciphers is provided several times, the last set value
is used.
Example:
curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com
See also --tls13-ciphers, --curves and --proxy-ciphers. Added in
7.61.0.
--proxy-tlsauthtype <type>
Same as --tlsauthtype but used in HTTPS proxy context.
If --proxy-tlsauthtype is provided several times, the last set value is
used.
Example:
curl --proxy-tlsauthtype SRP -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.
--proxy-tlspassword <string>
Same as --tlspassword but used in HTTPS proxy context.
If --proxy-tlspassword is provided several times, the last set value is
used.
Example:
curl --proxy-tlspassword passwd -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.
--proxy-tlsuser <name>
Same as --tlsuser but used in HTTPS proxy context.
If --proxy-tlsuser is provided several times, the last set value is
used.
Example:
curl --proxy-tlsuser smith -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlspassword. Added in 7.52.0.
--proxy-tlsv1
Same as -1, --tlsv1 but used in HTTPS proxy context.
Providing --proxy-tlsv1 multiple times has no extra effect.
Example:
curl --proxy-tlsv1 -x https://proxy https://example.com
See also -x, --proxy. Added in 7.52.0.
-U, --proxy-user <user:password>
Specify the user name and password to use for proxy authentication.
If you use a Windows SSPI-enabled curl binary and do either Negotiate
or NTLM authentication then you can tell curl to select the user name
and password from your environment by specifying a single colon with
this option: "-U :".
On systems where it works, curl hides the given option argument from
process listings. This is not enough to protect credentials from possi‐
bly getting seen by other users on the same system as they still are
visible for a moment before cleared. Such sensitive data should be re‐
trieved from a file instead or similar and never used in clear text in
a command line.
If -U, --proxy-user is provided several times, the last set value is
used.
Example:
curl --proxy-user name:pwd -x proxy https://example.com
See also --proxy-pass.
-x, --proxy [protocol://]host[:port]
Use the specified proxy.
The proxy string can be specified with a protocol:// prefix. No proto‐
col specified or http:// it is treated as an HTTP proxy. Use socks4://,
socks4a://, socks5:// or socks5h:// to request a specific SOCKS version
to be used.
Unix domain sockets are supported for socks proxy. Set localhost for
the host part. e.g. socks5h://localhost/path/to/socket.sock
HTTPS proxy support works set with the https:// protocol prefix for
OpenSSL and GnuTLS (added in 7.52.0). It also works for BearSSL,
mbedTLS, rustls, Schannel, Secure Transport and wolfSSL (added in
7.87.0).
Unrecognized and unsupported proxy protocols cause an error (added in
7.52.0). Ancient curl versions ignored unknown schemes and used
http:// instead.
If the port number is not specified in the proxy string, it is assumed
to be 1080.
This option overrides existing environment variables that set the proxy
to use. If there is an environment variable setting a proxy, you can
set proxy to "" to override it.
All operations that are performed over an HTTP proxy are transparently
converted to HTTP. It means that certain protocol specific operations
might not be available. This is not the case if you can tunnel through
the proxy, as one with the -p, --proxytunnel option.
User and password that might be provided in the proxy string are URL
decoded by curl. This allows you to pass in special characters such as
@ by using %40 or pass in a colon with %3a.
The proxy host can be specified the same way as the proxy environment
variables, including the protocol prefix (http://) and the embedded
user + password.
When a proxy is used, the active FTP mode as set with -P, --ftp-port,
cannot be used.
If -x, --proxy is provided several times, the last set value is used.
Example:
curl --proxy http://proxy.example https://example.com
See also --socks5 and --proxy-basic.
--proxy1.0 <host[:port]>
Use the specified HTTP 1.0 proxy. If the port number is not specified,
it is assumed at port 1080.
The only difference between this and the HTTP proxy option -x, --proxy,
is that attempts to use CONNECT through the proxy specifies an HTTP 1.0
protocol instead of the default HTTP 1.1.
Providing --proxy1.0 multiple times has no extra effect.
Example:
curl --proxy1.0 -x http://proxy https://example.com
See also -x, --proxy, --socks5 and --preproxy.
-p, --proxytunnel
When an HTTP proxy is used -x, --proxy, this option makes curl tunnel
the traffic through the proxy. The tunnel approach is made with the
HTTP proxy CONNECT request and requires that the proxy allows direct
connect to the remote port number curl wants to tunnel through to.
To suppress proxy CONNECT response headers when curl is set to output
headers use --suppress-connect-headers.
Providing -p, --proxytunnel multiple times has no extra effect. Dis‐
able it again with --no-proxytunnel.
Example:
curl --proxytunnel -x http://proxy https://example.com
See also -x, --proxy.
--pubkey <key>
(SFTP SCP) Public key file name. Allows you to provide your public key
in this separate file.
curl attempts to automatically extract the public key from the private
key file, so passing this option is generally not required. Note that
this public key extraction requires libcurl to be linked against a copy
of libssh2 1.2.8 or higher that is itself linked against OpenSSL.
If --pubkey is provided several times, the last set value is used.
Example:
curl --pubkey file.pub sftp://example.com/
See also --pass.
-Q, --quote <command>
(FTP SFTP) Send an arbitrary command to the remote FTP or SFTP server.
Quote commands are sent BEFORE the transfer takes place (just after the
initial PWD command in an FTP transfer, to be exact). To make commands
take place after a successful transfer, prefix them with a dash '-'.
(FTP only) To make commands be sent after curl has changed the working
directory, just before the file transfer command(s), prefix the command
with a '+'. This is not performed when a directory listing is per‐
formed.
You may specify any number of commands.
By default curl stops at first failure. To make curl continue even if
the command fails, prefix the command with an asterisk (*). Otherwise,
if the server returns failure for one of the commands, the entire oper‐
ation is aborted.
You must send syntactically correct FTP commands as RFC 959 defines to
FTP servers, or one of the commands listed below to SFTP servers.
SFTP is a binary protocol. Unlike for FTP, curl interprets SFTP quote
commands itself before sending them to the server. File names may be
quoted shell-style to embed spaces or special characters. Following is
the list of all supported SFTP quote commands:
"atime date file"
The atime command sets the last access time of the file named by
the file operand. The <date expression> can be all sorts of date
strings, see the curl_getdate(3) man page for date expression
details. (Added in 7.73.0)
"chgrp group file"
The chgrp command sets the group ID of the file named by the
file operand to the group ID specified by the group operand. The
group operand is a decimal integer group ID.
"chmod mode file"
The chmod command modifies the file mode bits of the specified
file. The mode operand is an octal integer mode number.
"chown user file"
The chown command sets the owner of the file named by the file
operand to the user ID specified by the user operand. The user
operand is a decimal integer user ID.
"ln source_file target_file"
The ln and symlink commands create a symbolic link at the tar‐
get_file location pointing to the source_file location.
"mkdir directory_name"
The mkdir command creates the directory named by the direc‐
tory_name operand.
"mtime date file"
The mtime command sets the last modification time of the file
named by the file operand. The <date expression> can be all
sorts of date strings, see the curl_getdate(3) man page for date
expression details. (Added in 7.73.0)
"pwd" The pwd command returns the absolute path name of the current
working directory.
"rename source target"
The rename command renames the file or directory named by the
source operand to the destination path named by the target
operand.
"rm file"
The rm command removes the file specified by the file operand.
"rmdir directory"
The rmdir command removes the directory entry specified by the
directory operand, provided it is empty.
"symlink source_file target_file"
See ln.
-Q, --quote can be used several times in a command line
Example:
curl --quote "DELE file" ftp://example.com/foo
See also -X, --request.
--random-file <file>
Deprecated option. This option is ignored (added in 7.84.0). Prior to
that it only had an effect on curl if built to use old versions of
OpenSSL.
Specify the path name to file containing random data. The data may be
used to seed the random engine for SSL connections.
If --random-file is provided several times, the last set value is used.
Example:
curl --random-file rubbish https://example.com
See also --egd-file.
-r, --range <range>
(HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial document)
from an HTTP/1.1, FTP or SFTP server or a local FILE. Ranges can be
specified in a number of ways.
0-499 specifies the first 500 bytes
500-999 specifies the second 500 bytes
-500 specifies the last 500 bytes
9500- specifies the bytes from offset 9500 and forward
0-0,-1 specifies the first and last byte only(*)(HTTP)
100-199,500-599
specifies two separate 100-byte ranges(*) (HTTP)
(*) = NOTE that this causes the server to reply with a multipart re‐
sponse, which is returned as-is by curl! Parsing or otherwise trans‐
forming this response is the responsibility of the caller.
Only digit characters (0-9) are valid in the 'start' and 'stop' fields
of the 'start-stop' range syntax. If a non-digit character is given in
the range, the server's response is unspecified, depending on the
server's configuration.
Many HTTP/1.1 servers do not have this feature enabled, so that when
you attempt to get a range, curl instead gets the whole document.
FTP and SFTP range downloads only support the simple 'start-stop' syn‐
tax (optionally with one of the numbers omitted). FTP use depends on
the extended FTP command SIZE.
If -r, --range is provided several times, the last set value is used.
Example:
curl --range 22-44 https://example.com
See also -C, --continue-at and -a, --append.
--rate <max request rate>
Specify the maximum transfer frequency you allow curl to use - in num‐
ber of transfer starts per time unit (sometimes called request rate).
Without this option, curl starts the next transfer as fast as possible.
If given several URLs and a transfer completes faster than the allowed
rate, curl waits until the next transfer is started to maintain the re‐
quested rate. This option has no effect when -Z, --parallel is used.
The request rate is provided as "N/U" where N is an integer number and
U is a time unit. Supported units are 's' (second), 'm' (minute), 'h'
(hour) and 'd' /(day, as in a 24 hour unit). The default time unit, if
no "/U" is provided, is number of transfers per hour.
If curl is told to allow 10 requests per minute, it does not start the
next request until 6 seconds have elapsed since the previous transfer
was started.
This function uses millisecond resolution. If the allowed frequency is
set more than 1000 per second, it instead runs unrestricted.
When retrying transfers, enabled with --retry, the separate retry delay
logic is used and not this setting.
This option is global and does not need to be specified for each use of
--next.
If --rate is provided several times, the last set value is used.
Examples:
curl --rate 2/s https://example.com ...
curl --rate 3/h https://example.com ...
curl --rate 14/m https://example.com ...
See also --limit-rate and --retry-delay. Added in 7.84.0.
--raw (HTTP) When used, it disables all internal HTTP decoding of content or
transfer encodings and instead makes them passed on unaltered, raw.
Providing --raw multiple times has no extra effect. Disable it again
with --no-raw.
Example:
curl --raw https://example.com
See also --tr-encoding.
-e, --referer <URL>
(HTTP) Sends the "Referrer Page" information to the HTTP server. This
can also be set with the -H, --header flag of course. When used with
-L, --location you can append ";auto" to the -e, --referer URL to make
curl automatically set the previous URL when it follows a Location:
header. The ";auto" string can be used alone, even if you do not set an
initial -e, --referer.
If -e, --referer is provided several times, the last set value is used.
Examples:
curl --referer "https://fake.example" https://example.com
curl --referer "https://fake.example;auto" -L https://example.com
curl --referer ";auto" -L https://example.com
See also -A, --user-agent and -H, --header.
-J, --remote-header-name
(HTTP) This option tells the -O, --remote-name option to use the
server-specified Content-Disposition filename instead of extracting a
filename from the URL. If the server-provided file name contains a
path, that is stripped off before the file name is used.
The file is saved in the current directory, or in the directory speci‐
fied with --output-dir.
If the server specifies a file name and a file with that name already
exists in the destination directory, it is not overwritten and an error
occurs - unless you allow it by using the --clobber option. If the
server does not specify a file name then this option has no effect.
There is no attempt to decode %-sequences (yet) in the provided file
name, so this option may provide you with rather unexpected file names.
This feature uses the name from the "filename" field, it does not yet
support the "filename*" field (filenames with explicit character sets).
WARNING: Exercise judicious use of this option, especially on Windows.
A rogue server could send you the name of a DLL or other file that
could be loaded automatically by Windows or some third party software.
Providing -J, --remote-header-name multiple times has no extra effect.
Disable it again with --no-remote-header-name.
Example:
curl -OJ https://example.com/file
See also -O, --remote-name.
--remote-name-all
This option changes the default action for all given URLs to be dealt
with as if -O, --remote-name were used for each one. So if you want to
disable that for a specific URL after --remote-name-all has been used,
you must use "-o -" or --no-remote-name.
Providing --remote-name-all multiple times has no extra effect. Dis‐
able it again with --no-remote-name-all.
Example:
curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2
See also -O, --remote-name.
-O, --remote-name
Write output to a local file named like the remote file we get. (Only
the file part of the remote file is used, the path is cut off.)
The file is saved in the current working directory. If you want the
file saved in a different directory, make sure you change the current
working directory before invoking curl with this option or use --out‐
put-dir.
The remote file name to use for saving is extracted from the given URL,
nothing else, and if it already exists it is overwritten. If you want
the server to be able to choose the file name refer to -J, --re‐
mote-header-name which can be used in addition to this option. If the
server chooses a file name and that name already exists it is not over‐
written.
There is no URL decoding done on the file name. If it has %20 or other
URL encoded parts of the name, they end up as-is as file name.
You may use this option as many times as the number of URLs you have.
-O, --remote-name can be used several times in a command line
Example:
curl -O https://example.com/filename
See also --remote-name-all, --output-dir and -J, --remote-header-name.
-R, --remote-time
Makes curl attempt to figure out the timestamp of the remote file that
is getting downloaded, and if that is available make the local file get
that same timestamp.
Providing -R, --remote-time multiple times has no extra effect. Dis‐
able it again with --no-remote-time.
Example:
curl --remote-time -o foo https://example.com
See also -O, --remote-name and -z, --time-cond.
--remove-on-error
When curl returns an error when told to save output in a local file,
this option removes that saved file before exiting. This prevents curl
from leaving a partial file in the case of an error during transfer.
If the output is not a file, this option has no effect.
Providing --remove-on-error multiple times has no extra effect. Dis‐
able it again with --no-remove-on-error.
Example:
curl --remove-on-error -o output https://example.com
See also -f, --fail. Added in 7.83.0.
--request-target <path>
(HTTP) Tells curl to use an alternative "target" (path) instead of us‐
ing the path as provided in the URL. Particularly useful when wanting
to issue HTTP requests without leading slash or other data that does
not follow the regular URL pattern, like "OPTIONS *".
curl passes on the verbatim string you give it its the request without
any filter or other safe guards. That includes white space and control
characters.
If --request-target is provided several times, the last set value is
used.
Example:
curl --request-target "*" -X OPTIONS https://example.com
See also -X, --request. Added in 7.55.0.
-X, --request <method>
Change the method to use when starting the transfer.
curl passes on the verbatim string you give it its the request without
any filter or other safe guards. That includes white space and control
characters.
HTTP Specifies a custom request method to use when communi‐
cating with the HTTP server. The specified request
method is used instead of the method otherwise used
(which defaults to GET). Read the HTTP 1.1 specification
for details and explanations. Common additional HTTP re‐
quests include PUT and DELETE, but related technologies
like WebDAV offers PROPFIND, COPY, MOVE and more.
Normally you do not need this option. All sorts of GET,
HEAD, POST and PUT requests are rather invoked by using
dedicated command line options.
This option only changes the actual word used in the
HTTP request, it does not alter the way curl behaves. So
for example if you want to make a proper HEAD request,
using -X HEAD does not suffice. You need to use the -I,
--head option.
The method string you set with -X, --request is used for
all requests, which if you for example use -L, --loca‐
tion may cause unintended side-effects when curl does
not change request method according to the HTTP 30x re‐
sponse codes - and similar.
FTP Specifies a custom FTP command to use instead of LIST
when doing file lists with FTP.
POP3 Specifies a custom POP3 command to use instead of LIST
or RETR.
IMAP Specifies a custom IMAP command to use instead of LIST.
SMTP Specifies a custom SMTP command to use instead of HELP
or VRFY.
If -X, --request is provided several times, the last set value is used.
Examples:
curl -X "DELETE" https://example.com
curl -X NLST ftp://example.com/
See also --request-target.
--resolve <[+]host:port:addr[,addr]...>
Provide a custom address for a specific host and port pair. Using this,
you can make the curl requests(s) use a specified address and prevent
the otherwise normally resolved address to be used. Consider it a sort
of /etc/hosts alternative provided on the command line. The port number
should be the number used for the specific protocol the host is used
for. It means you need several entries if you want to provide address
for the same host but different ports.
By specifying '*' as host you can tell curl to resolve any host and
specific port pair to the specified address. Wildcard is resolved last
so any --resolve with a specific host and port is used first.
The provided address set by this option is used even if -4, --ipv4 or
-6, --ipv6 is set to make curl use another IP version.
By prefixing the host with a '+' you can make the entry time out after
curl's default timeout (1 minute). Note that this only makes sense for
long running parallel transfers with a lot of files. In such cases, if
this option is used curl tries to resolve the host as it normally would
once the timeout has expired.
Support for providing the IP address within [brackets] was added in
7.57.0.
Support for providing multiple IP addresses per entry was added in
7.59.0.
Support for resolving with wildcard was added in 7.64.0.
Support for the '+' prefix was was added in 7.75.0.
--resolve can be used several times in a command line
Example:
curl --resolve example.com:443:127.0.0.1 https://example.com
See also --connect-to and --alt-svc.
--retry-all-errors
Retry on any error. This option is used together with --retry.
This option is the "sledgehammer" of retrying. Do not use this option
by default (for example in your curlrc), there may be unintended conse‐
quences such as sending or receiving duplicate data. Do not use with
redirected input or output. You'd be much better off handling your
unique problems in shell script. Please read the example below.
WARNING: For server compatibility curl attempts to retry failed flaky
transfers as close as possible to how they were started, but this is
not possible with redirected input or output. For example, before
retrying it removes output data from a failed partial transfer that was
written to an output file. However this is not true of data redirected
to a | pipe or > file, which are not reset. We strongly suggest you do
not parse or record output via redirect in combination with this op‐
tion, since you may receive duplicate data.
By default curl does not return error for transfers with an HTTP re‐
sponse code that indicates an HTTP error, if the transfer was success‐
ful. For example, if a server replies 404 Not Found and the reply is
fully received then that is not an error. When --retry is used then
curl retries on some HTTP response codes that indicate transient HTTP
errors, but that does not include most 4xx response codes such as 404.
If you want to retry on all response codes that indicate HTTP errors
(4xx and 5xx) then combine with -f, --fail.
Providing --retry-all-errors multiple times has no extra effect. Dis‐
able it again with --no-retry-all-errors.
Example:
curl --retry 5 --retry-all-errors https://example.com
See also --retry. Added in 7.71.0.
--retry-connrefused
In addition to the other conditions, consider ECONNREFUSED as a tran‐
sient error too for --retry. This option is used together with --retry.
Providing --retry-connrefused multiple times has no extra effect. Dis‐
able it again with --no-retry-connrefused.
Example:
curl --retry-connrefused --retry 7 https://example.com
See also --retry and --retry-all-errors. Added in 7.52.0.
--retry-delay <seconds>
Make curl sleep this amount of time before each retry when a transfer
has failed with a transient error (it changes the default backoff time
algorithm between retries). This option is only interesting if --retry
is also used. Setting this delay to zero makes curl use the default
backoff time.
If --retry-delay is provided several times, the last set value is used.
Example:
curl --retry-delay 5 --retry 7 https://example.com
See also --retry.
--retry-max-time <seconds>
The retry timer is reset before the first transfer attempt. Retries are
done as usual (see --retry) as long as the timer has not reached this
given limit. Notice that if the timer has not reached the limit, the
request is made and while performing, it may take longer than this
given time period. To limit a single request's maximum time, use -m,
--max-time. Set this option to zero to not timeout retries.
If --retry-max-time is provided several times, the last set value is
used.
Example:
curl --retry-max-time 30 --retry 10 https://example.com
See also --retry.
--retry <num>
If a transient error is returned when curl tries to perform a transfer,
it retries this number of times before giving up. Setting the number to
0 makes curl do no retries (which is the default). Transient error
means either: a timeout, an FTP 4xx response code or an HTTP 408, 429,
500, 502, 503 or 504 response code.
When curl is about to retry a transfer, it first waits one second and
then for all forthcoming retries it doubles the waiting time until it
reaches 10 minutes which then remains delay between the rest of the re‐
tries. By using --retry-delay you disable this exponential backoff al‐
gorithm. See also --retry-max-time to limit the total time allowed for
retries.
curl complies with the Retry-After: response header if one was present
to know when to issue the next retry (added in 7.66.0).
If --retry is provided several times, the last set value is used.
Example:
curl --retry 7 https://example.com
See also --retry-max-time.
--sasl-authzid <identity>
Use this authorization identity (authzid), during SASL PLAIN authenti‐
cation, in addition to the authentication identity (authcid) as speci‐
fied by -u, --user.
If the option is not specified, the server derives the authzid from the
authcid, but if specified, and depending on the server implementation,
it may be used to access another user's inbox, that the user has been
granted access to, or a shared mailbox for example.
If --sasl-authzid is provided several times, the last set value is
used.
Example:
curl --sasl-authzid zid imap://example.com/
See also --login-options. Added in 7.66.0.
--sasl-ir
Enable initial response in SASL authentication.
Providing --sasl-ir multiple times has no extra effect. Disable it
again with --no-sasl-ir.
Example:
curl --sasl-ir imap://example.com/
See also --sasl-authzid.
--service-name <name>
This option allows you to change the service name for SPNEGO.
If --service-name is provided several times, the last set value is
used.
Example:
curl --service-name sockd/server https://example.com
See also --negotiate and --proxy-service-name.
-S, --show-error
When used with -s, --silent, it makes curl show an error message if it
fails.
This option is global and does not need to be specified for each use of
--next.
Providing -S, --show-error multiple times has no extra effect. Disable
it again with --no-show-error.
Example:
curl --show-error --silent https://example.com
See also --no-progress-meter.
-s, --silent
Silent or quiet mode. Do not show progress meter or error messages.
Makes Curl mute. It still outputs the data you ask for, potentially
even to the terminal/stdout unless you redirect it.
Use -S, --show-error in addition to this option to disable progress me‐
ter but still show error messages.
Providing -s, --silent multiple times has no extra effect. Disable it
again with --no-silent.
Example:
curl -s https://example.com
See also -v, --verbose, --stderr and --no-progress-meter.
--socks4 <host[:port]>
Use the specified SOCKS4 proxy. If the port number is not specified, it
is assumed at port 1080. Using this socket type make curl resolve the
host name and passing the address on to the proxy.
To specify proxy on a unix domain socket, use localhost for host, e.g.
socks4://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they are mu‐
tually exclusive.
This option is superfluous since you can specify a socks4 proxy with
-x, --proxy using a socks4:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time proxy
is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a case,
curl first connects to the SOCKS proxy and then connects (through
SOCKS) to the HTTP or HTTPS proxy.
If --socks4 is provided several times, the last set value is used.
Example:
curl --socks4 hostname:4096 https://example.com
See also --socks4a, --socks5 and --socks5-hostname.
--socks4a <host[:port]>
Use the specified SOCKS4a proxy. If the port number is not specified,
it is assumed at port 1080. This asks the proxy to resolve the host
name.
To specify proxy on a unix domain socket, use localhost for host, e.g.
socks4a://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they are mu‐
tually exclusive.
This option is superfluous since you can specify a socks4a proxy with
-x, --proxy using a socks4a:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a
case, curl first connects to the SOCKS proxy and then connects (through
SOCKS) to the HTTP or HTTPS proxy.
If --socks4a is provided several times, the last set value is used.
Example:
curl --socks4a hostname:4096 https://example.com
See also --socks4, --socks5 and --socks5-hostname.
--socks5-basic
Tells curl to use username/password authentication when connecting to a
SOCKS5 proxy. The username/password authentication is enabled by de‐
fault. Use --socks5-gssapi to force GSS-API authentication to SOCKS5
proxies.
Providing --socks5-basic multiple times has no extra effect.
Example:
curl --socks5-basic --socks5 hostname:4096 https://example.com
See also --socks5. Added in 7.55.0.
--socks5-gssapi-nec
As part of the GSS-API negotiation a protection mode is negotiated. RFC
1961 says in section 4.3/4.4 it should be protected, but the NEC refer‐
ence implementation does not. The option --socks5-gssapi-nec allows the
unprotected exchange of the protection mode negotiation.
Providing --socks5-gssapi-nec multiple times has no extra effect. Dis‐
able it again with --no-socks5-gssapi-nec.
Example:
curl --socks5-gssapi-nec --socks5 hostname:4096 https://example.com
See also --socks5.
--socks5-gssapi-service <name>
The default service name for a socks server is rcmd/server-fqdn. This
option allows you to change it.
If --socks5-gssapi-service is provided several times, the last set
value is used.
Example:
curl --socks5-gssapi-service sockd --socks5 hostname:4096 https://example.com
See also --socks5.
--socks5-gssapi
Tells curl to use GSS-API authentication when connecting to a SOCKS5
proxy. The GSS-API authentication is enabled by default (if curl is
compiled with GSS-API support). Use --socks5-basic to force user‐
name/password authentication to SOCKS5 proxies.
Providing --socks5-gssapi multiple times has no extra effect. Disable
it again with --no-socks5-gssapi.
Example:
curl --socks5-gssapi --socks5 hostname:4096 https://example.com
See also --socks5. Added in 7.55.0.
--socks5-hostname <host[:port]>
Use the specified SOCKS5 proxy (and let the proxy resolve the host
name). If the port number is not specified, it is assumed at port 1080.
To specify proxy on a unix domain socket, use localhost for host, e.g.
socks5h://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they are mu‐
tually exclusive.
This option is superfluous since you can specify a socks5 hostname
proxy with -x, --proxy using a socks5h:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a
case, curl first connects to the SOCKS proxy and then connects (through
SOCKS) to the HTTP or HTTPS proxy.
If --socks5-hostname is provided several times, the last set value is
used.
Example:
curl --socks5-hostname proxy.example:7000 https://example.com
See also --socks5 and --socks4a.
--socks5 <host[:port]>
Use the specified SOCKS5 proxy - but resolve the host name locally. If
the port number is not specified, it is assumed at port 1080.
To specify proxy on a unix domain socket, use localhost for host, e.g.
socks5://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they are mu‐
tually exclusive.
This option is superfluous since you can specify a socks5 proxy with
-x, --proxy using a socks5:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a
case, curl first connects to the SOCKS proxy and then connects (through
SOCKS) to the HTTP or HTTPS proxy.
This option (as well as --socks4) does not work with IPV6, FTPS or
LDAP.
If --socks5 is provided several times, the last set value is used.
Example:
curl --socks5 proxy.example:7000 https://example.com
See also --socks5-hostname and --socks4a.
-Y, --speed-limit <speed>
If a transfer is slower than this given speed (in bytes per second) for
speed-time seconds it gets aborted. speed-time is set with -y,
--speed-time and is 30 if not set.
If -Y, --speed-limit is provided several times, the last set value is
used.
Example:
curl --speed-limit 300 --speed-time 10 https://example.com
See also -y, --speed-time, --limit-rate and -m, --max-time.
-y, --speed-time <seconds>
If a transfer runs slower than speed-limit bytes per second during a
speed-time period, the transfer is aborted. If speed-time is used, the
default speed-limit is 1 unless set with -Y, --speed-limit.
This option controls transfers (in both directions) but does not affect
slow connects etc. If this is a concern for you, try the --con‐
nect-timeout option.
If -y, --speed-time is provided several times, the last set value is
used.
Example:
curl --speed-limit 300 --speed-time 10 https://example.com
See also -Y, --speed-limit and --limit-rate.
--ssl-allow-beast
This option tells curl to not work around a security flaw in the SSL3
and TLS1.0 protocols known as BEAST. If this option is not used, the
SSL layer may use workarounds known to cause interoperability problems
with some older SSL implementations.
WARNING: this option loosens the SSL security, and by using this flag
you ask for exactly that.
Providing --ssl-allow-beast multiple times has no extra effect. Dis‐
able it again with --no-ssl-allow-beast.
Example:
curl --ssl-allow-beast https://example.com
See also --proxy-ssl-allow-beast and -k, --insecure.
--ssl-auto-client-cert
(Schannel) Tell libcurl to automatically locate and use a client cer‐
tificate for authentication, when requested by the server. Since the
server can request any certificate that supports client authentication
in the OS certificate store it could be a privacy violation and unex‐
pected.
Providing --ssl-auto-client-cert multiple times has no extra effect.
Disable it again with --no-ssl-auto-client-cert.
Example:
curl --ssl-auto-client-cert https://example.com
See also --proxy-ssl-auto-client-cert. Added in 7.77.0.
--ssl-no-revoke
(Schannel) This option tells curl to disable certificate revocation
checks. WARNING: this option loosens the SSL security, and by using
this flag you ask for exactly that.
Providing --ssl-no-revoke multiple times has no extra effect. Disable
it again with --no-ssl-no-revoke.
Example:
curl --ssl-no-revoke https://example.com
See also --crlfile.
--ssl-reqd
(FTP IMAP POP3 SMTP LDAP) Require SSL/TLS for the connection. Termi‐
nates the connection if the transfer cannot be upgraded to use SSL/TLS.
This option is handled in LDAP (added in 7.81.0). It is fully supported
by the OpenLDAP backend and rejected by the generic ldap backend if ex‐
plicit TLS is required.
This option is unnecessary if you use a URL scheme that in itself im‐
plies immediate and implicit use of TLS, like for FTPS, IMAPS, POP3S,
SMTPS and LDAPS. Such a transfer always fails if the TLS handshake does
not work.
This option was formerly known as --ftp-ssl-reqd.
Providing --ssl-reqd multiple times has no extra effect. Disable it
again with --no-ssl-reqd.
Example:
curl --ssl-reqd ftp://example.com
See also --ssl and -k, --insecure.
--ssl-revoke-best-effort
(Schannel) This option tells curl to ignore certificate revocation
checks when they failed due to missing/offline distribution points for
the revocation check lists.
Providing --ssl-revoke-best-effort multiple times has no extra effect.
Disable it again with --no-ssl-revoke-best-effort.
Example:
curl --ssl-revoke-best-effort https://example.com
See also --crlfile and -k, --insecure. Added in 7.70.0.
--ssl (FTP IMAP POP3 SMTP LDAP) Warning: this is considered an insecure op‐
tion. Consider using --ssl-reqd instead to be sure curl upgrades to a
secure connection.
Try to use SSL/TLS for the connection. Reverts to a non-secure connec‐
tion if the server does not support SSL/TLS. See also --ftp-ssl-control
and --ssl-reqd for different levels of encryption required.
This option is handled in LDAP (added in 7.81.0). It is fully supported
by the OpenLDAP backend and ignored by the generic ldap backend.
Please note that a server may close the connection if the negotiation
does not succeed.
This option was formerly known as --ftp-ssl. That option name can still
be used but might be removed in a future version.
Providing --ssl multiple times has no extra effect. Disable it again
with --no-ssl.
Example:
curl --ssl pop3://example.com/
See also --ssl-reqd, -k, --insecure and --ciphers.
-2, --sslv2
(SSL) This option previously asked curl to use SSLv2, but is now ig‐
nored (added in 7.77.0). SSLv2 is widely considered insecure (see RFC
6176).
Providing -2, --sslv2 multiple times has no extra effect.
Example:
curl --sslv2 https://example.com
See also --http1.1 and --http2. -2, --sslv2 requires that the underly‐
ing libcurl was built to support TLS. This option is mutually exclusive
to -3, --sslv3 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.
-3, --sslv3
(SSL) This option previously asked curl to use SSLv3, but is now ig‐
nored (added in 7.77.0). SSLv3 is widely considered insecure (see RFC
7568).
Providing -3, --sslv3 multiple times has no extra effect.
Example:
curl --sslv3 https://example.com
See also --http1.1 and --http2. -3, --sslv3 requires that the underly‐
ing libcurl was built to support TLS. This option is mutually exclusive
to -2, --sslv2 and -1, --tlsv1 and --tlsv1.1 and --tlsv1.2.
--stderr <file>
Redirect all writes to stderr to the specified file instead. If the
file name is a plain '-', it is instead written to stdout.
This option is global and does not need to be specified for each use of
--next.
If --stderr is provided several times, the last set value is used.
Example:
curl --stderr output.txt https://example.com
See also -v, --verbose and -s, --silent.
--styled-output
Enables the automatic use of bold font styles when writing HTTP headers
to the terminal. Use --no-styled-output to switch them off.
Styled output requires a terminal that supports bold fonts. This fea‐
ture is not present on curl for Windows due to lack of this capability.
This option is global and does not need to be specified for each use of
--next.
Providing --styled-output multiple times has no extra effect. Disable
it again with --no-styled-output.
Example:
curl --styled-output -I https://example.com
See also -I, --head and -v, --verbose. Added in 7.61.0.
--suppress-connect-headers
When -p, --proxytunnel is used and a CONNECT request is made do not
output proxy CONNECT response headers. This option is meant to be used
with -D, --dump-header or -i, --include which are used to show protocol
headers in the output. It has no effect on debug options such as -v,
--verbose or --trace, or any statistics.
Providing --suppress-connect-headers multiple times has no extra ef‐
fect. Disable it again with --no-suppress-connect-headers.
Example:
curl --suppress-connect-headers --include -x proxy https://example.com
See also -D, --dump-header, -i, --include and -p, --proxytunnel. Added
in 7.54.0.
--tcp-fastopen
Enable use of TCP Fast Open (RFC 7413). TCP Fast Open is a TCP exten‐
sion that allows data to get sent earlier over the connection (before
the final handshake ACK) if the client and server have been connected
previously.
Providing --tcp-fastopen multiple times has no extra effect. Disable
it again with --no-tcp-fastopen.
Example:
curl --tcp-fastopen https://example.com
See also --false-start.
--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man page
for details about this option.
curl sets this option by default and you need to explicitly switch it
off if you do not want it on (added in 7.50.2).
Providing --tcp-nodelay multiple times has no extra effect. Disable it
again with --no-tcp-nodelay.
Example:
curl --tcp-nodelay https://example.com
See also -N, --no-buffer.
-t, --telnet-option <opt=val>
Pass options to the telnet protocol. Supported options are:
TTYPE=<term> Sets the terminal type.
XDISPLOC=<X display> Sets the X display location.
NEW_ENV=<var,val> Sets an environment variable.
-t, --telnet-option can be used several times in a command line
Example:
curl -t TTYPE=vt100 telnet://example.com/
See also -K, --config.
--tftp-blksize <value>
(TFTP) Set the TFTP BLKSIZE option (must be >512). This is the block
size that curl tries to use when transferring data to or from a TFTP
server. By default 512 bytes are used.
If --tftp-blksize is provided several times, the last set value is
used.
Example:
curl --tftp-blksize 1024 tftp://example.com/file
See also --tftp-no-options.
--tftp-no-options
(TFTP) Tells curl not to send TFTP options requests.
This option improves interop with some legacy servers that do not ac‐
knowledge or properly implement TFTP options. When this option is used
--tftp-blksize is ignored.
Providing --tftp-no-options multiple times has no extra effect. Dis‐
able it again with --no-tftp-no-options.
Example:
curl --tftp-no-options tftp://192.168.0.1/
See also --tftp-blksize.
-z, --time-cond <time>
(HTTP FTP) Request a file that has been modified later than the given
time and date, or one that has been modified before that time. The
<date expression> can be all sorts of date strings or if it does not
match any internal ones, it is taken as a filename and tries to get the
modification date (mtime) from <file> instead. See the curl_getdate(3)
man pages for date expression details.
Start the date expression with a dash (-) to make it request for a doc‐
ument that is older than the given date/time, default is a document
that is newer than the specified date/time.
If provided a non-existing file, curl outputs a warning about that fact
and proceeds to do the transfer without a time condition.
If -z, --time-cond is provided several times, the last set value is
used.
Examples:
curl -z "Wed 01 Sep 2021 12:18:00" https://example.com
curl -z "-Wed 01 Sep 2021 12:18:00" https://example.com
curl -z file https://example.com
See also --etag-compare and -R, --remote-time.
--tls-max <VERSION>
(TLS) VERSION defines maximum supported TLS version. The minimum ac‐
ceptable version is set by tlsv1.0, tlsv1.1, tlsv1.2 or tlsv1.3.
If the connection is done without TLS, this option has no effect. This
includes QUIC-using (HTTP/3) transfers.
default
Use up to recommended TLS version.
1.0 Use up to TLSv1.0.
1.1 Use up to TLSv1.1.
1.2 Use up to TLSv1.2.
1.3 Use up to TLSv1.3.
If --tls-max is provided several times, the last set value is used.
Examples:
curl --tls-max 1.2 https://example.com
curl --tls-max 1.3 --tlsv1.2 https://example.com
See also --tlsv1.0, --tlsv1.1, --tlsv1.2 and --tlsv1.3. --tls-max re‐
quires that the underlying libcurl was built to support TLS. Added in
7.54.0.
--tls13-ciphers <ciphersuite list>
(TLS) Specifies which cipher suites to use in the connection if it ne‐
gotiates TLS 1.3. The list of ciphers suites must specify valid ci‐
phers. Read up on TLS 1.3 cipher suite details on this URL:
https://curl.se/docs/ssl-ciphers.html
This option is currently used only when curl is built to use OpenSSL
1.1.1 or later, or Schannel. If you are using a different SSL backend
you can try setting TLS 1.3 cipher suites by using the --ciphers op‐
tion.
If --tls13-ciphers is provided several times, the last set value is
used.
Example:
curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com
See also --ciphers, --curves and --proxy-tls13-ciphers. Added in
7.61.0.
--tlsauthtype <type>
Set TLS authentication type. Currently, the only supported option is
"SRP", for TLS-SRP (RFC 5054). If --tlsuser and --tlspassword are spec‐
ified but --tlsauthtype is not, then this option defaults to "SRP".
This option works only if the underlying libcurl is built with TLS-SRP
support, which requires OpenSSL or GnuTLS with TLS-SRP support.
If --tlsauthtype is provided several times, the last set value is used.
Example:
curl --tlsauthtype SRP https://example.com
See also --tlsuser.
--tlspassword <string>
Set password for use with the TLS authentication method specified with
--tlsauthtype. Requires that --tlsuser also be set.
This option does not work with TLS 1.3.
If --tlspassword is provided several times, the last set value is used.
Example:
curl --tlspassword pwd --tlsuser user https://example.com
See also --tlsuser.
--tlsuser <name>
Set username for use with the TLS authentication method specified with
--tlsauthtype. Requires that --tlspassword also is set.
This option does not work with TLS 1.3.
If --tlsuser is provided several times, the last set value is used.
Example:
curl --tlspassword pwd --tlsuser user https://example.com
See also --tlspassword.
--tlsv1.0
(TLS) Forces curl to use TLS version 1.0 or later when connecting to a
remote TLS server.
In old versions of curl this option was documented to allow _only_ TLS
1.0. That behavior was inconsistent depending on the TLS library. Use
--tls-max if you want to set a maximum TLS version.
Providing --tlsv1.0 multiple times has no extra effect.
Example:
curl --tlsv1.0 https://example.com
See also --tlsv1.3.
--tlsv1.1
(TLS) Forces curl to use TLS version 1.1 or later when connecting to a
remote TLS server.
In old versions of curl this option was documented to allow _only_ TLS
1.1. That behavior was inconsistent depending on the TLS library. Use
--tls-max if you want to set a maximum TLS version.
Providing --tlsv1.1 multiple times has no extra effect.
Example:
curl --tlsv1.1 https://example.com
See also --tlsv1.3 and --tls-max.
--tlsv1.2
(TLS) Forces curl to use TLS version 1.2 or later when connecting to a
remote TLS server.
In old versions of curl this option was documented to allow _only_ TLS
1.2. That behavior was inconsistent depending on the TLS library. Use
--tls-max if you want to set a maximum TLS version.
Providing --tlsv1.2 multiple times has no extra effect.
Example:
curl --tlsv1.2 https://example.com
See also --tlsv1.3 and --tls-max.
--tlsv1.3
(TLS) Forces curl to use TLS version 1.3 or later when connecting to a
remote TLS server.
If the connection is done without TLS, this option has no effect. This
includes QUIC-using (HTTP/3) transfers.
Note that TLS 1.3 is not supported by all TLS backends.
Providing --tlsv1.3 multiple times has no extra effect.
Example:
curl --tlsv1.3 https://example.com
See also --tlsv1.2 and --tls-max. Added in 7.52.0.
-1, --tlsv1
(TLS) Tells curl to use at least TLS version 1.x when negotiating with
a remote TLS server. That means TLS version 1.0 or higher
Providing -1, --tlsv1 multiple times has no extra effect.
Example:
curl --tlsv1 https://example.com
See also --http1.1 and --http2. -1, --tlsv1 requires that the underly‐
ing libcurl was built to support TLS. This option is mutually exclusive
to --tlsv1.1 and --tlsv1.2 and --tlsv1.3.
--tr-encoding
(HTTP) Request a compressed Transfer-Encoding response using one of the
algorithms curl supports, and uncompress the data while receiving it.
Providing --tr-encoding multiple times has no extra effect. Disable it
again with --no-tr-encoding.
Example:
curl --tr-encoding https://example.com
See also --compressed.
--trace-ascii <file>
Enables a full trace dump of all incoming and outgoing data, including
descriptive information, to the given output file. Use "-" as filename
to have the output sent to stdout.
This is similar to --trace, but leaves out the hex part and only shows
the ASCII part of the dump. It makes smaller output that might be eas‐
ier to read for untrained humans.
Note that verbose output of curl activities and network traffic might
contain sensitive data, including user names, credentials or secret
data content. Be aware and be careful when sharing trace logs with oth‐
ers.
This option is global and does not need to be specified for each use of
--next.
If --trace-ascii is provided several times, the last set value is used.
Example:
curl --trace-ascii log.txt https://example.com
See also -v, --verbose and --trace. This option is mutually exclusive
to --trace and -v, --verbose.
--trace-config <string>
Set configuration for trace output. A comma-separated list of compo‐
nents where detailed output can be made available from. Names are
case-insensitive. Specify 'all' to enable all trace components.
In addition to trace component names, specify "ids" and "time" to avoid
extra --trace-ids or --trace-time parameters.
See the curl_global_trace(3) man page for more details.
This option is global and does not need to be specified for each use of
--next.
--trace-config can be used several times in a command line
Example:
curl --trace-config ids,http/2 https://example.com
See also -v, --verbose and --trace. This option is mutually exclusive
to --trace and -v, --verbose. Added in 8.3.0.
--trace-ids
Prepends the transfer and connection identifiers to each trace or ver‐
bose line that curl displays.
This option is global and does not need to be specified for each use of
--next.
Providing --trace-ids multiple times has no extra effect. Disable it
again with --no-trace-ids.
Example:
curl --trace-ids --trace-ascii output https://example.com
See also --trace and -v, --verbose. Added in 8.2.0.
--trace-time
Prepends a time stamp to each trace or verbose line that curl displays.
This option is global and does not need to be specified for each use of
--next.
Providing --trace-time multiple times has no extra effect. Disable it
again with --no-trace-time.
Example:
curl --trace-time --trace-ascii output https://example.com
See also --trace and -v, --verbose.
--trace <file>
Enables a full trace dump of all incoming and outgoing data, including
descriptive information, to the given output file. Use "-" as filename
to have the output sent to stdout. Use "%" as filename to have the out‐
put sent to stderr.
Note that verbose output of curl activities and network traffic might
contain sensitive data, including user names, credentials or secret
data content. Be aware and be careful when sharing trace logs with oth‐
ers.
This option is global and does not need to be specified for each use of
--next.
If --trace is provided several times, the last set value is used.
Example:
curl --trace log.txt https://example.com
See also --trace-ascii, --trace-config, --trace-ids and --trace-time.
This option is mutually exclusive to -v, --verbose and --trace-ascii.
--unix-socket <path>
(HTTP) Connect through this Unix domain socket, instead of using the
network.
If --unix-socket is provided several times, the last set value is used.
Example:
curl --unix-socket socket-path https://example.com
See also --abstract-unix-socket.
-T, --upload-file <file>
This transfers the specified local file to the remote URL.
If there is no file part in the specified URL, curl appends the local
file name to the end of the URL before the operation starts. You must
use a trailing slash (/) on the last directory to prove to curl that
there is no file name or curl thinks that your last directory name is
the remote file name to use.
When putting the local file name at the end of the URL, curl ignores
what is on the left side of any slash (/) or backslash (\) used in the
file name and only appends what is on the right side of the rightmost
such character.
Use the file name "-" (a single dash) to use stdin instead of a given
file. Alternately, the file name "." (a single period) may be speci‐
fied instead of "-" to use stdin in non-blocking mode to allow reading
server output while stdin is being uploaded.
If this option is used with a HTTP(S) URL, the PUT method is used.
You can specify one -T, --upload-file for each URL on the command line.
Each -T, --upload-file + URL pair specifies what to upload and to
where. curl also supports "globbing" of the -T, --upload-file argument,
meaning that you can upload multiple files to a single URL by using the
same URL globbing style supported in the URL.
When uploading to an SMTP server: the uploaded data is assumed to be
RFC 5322 formatted. It has to feature the necessary set of headers and
mail body formatted correctly by the user as curl does not transcode
nor encode it further in any way.
-T, --upload-file can be used several times in a command line
Examples:
curl -T file https://example.com
curl -T "img[1-1000].png" ftp://ftp.example.com/
curl --upload-file "{file1,file2}" https://example.com
See also -G, --get, -I, --head, -X, --request and -d, --data.
--url-query <data>
(all) This option adds a piece of data, usually a name + value pair, to
the end of the URL query part. The syntax is identical to that used for
--data-urlencode with one extension:
If the argument starts with a '+' (plus), the rest of the string is
provided as-is unencoded.
The query part of a URL is the one following the question mark on the
right end.
--url-query can be used several times in a command line
Examples:
curl --url-query name=val https://example.com
curl --url-query =encodethis http://example.net/foo
curl --url-query name@file https://example.com
curl --url-query @fileonly https://example.com
curl --url-query "+name=%20foo" https://example.com
See also --data-urlencode and -G, --get. Added in 7.87.0.
--url <url>
Specify a URL to fetch. This option is mostly handy when you want to
specify URL(s) in a config file.
If the given URL is missing a scheme name (such as "http://" or
"ftp://" etc) then curl makes a guess based on the host. If the outer‐
most subdomain name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP then
that protocol is used, otherwise HTTP is used. Guessing can be avoided
by providing a full URL including the scheme, or disabled by setting a
default protocol (added in 7.45.0), see --proto-default for details.
To control where this URL is written, use the -o, --output or the -O,
--remote-name options.
WARNING: On Windows, particular file:// accesses can be converted to
network accesses by the operating system. Beware!
--url can be used several times in a command line
Example:
curl --url https://example.com
See also -:, --next and -K, --config.
-B, --use-ascii
(FTP LDAP) Enable ASCII transfer. For FTP, this can also be enforced by
using a URL that ends with ";type=A". This option causes data sent to
stdout to be in text mode for win32 systems.
Providing -B, --use-ascii multiple times has no extra effect. Disable
it again with --no-use-ascii.
Example:
curl -B ftp://example.com/README
See also --crlf and --data-ascii.
-A, --user-agent <name>
(HTTP) Specify the User-Agent string to send to the HTTP server. To en‐
code blanks in the string, surround the string with single quote marks.
This header can also be set with the -H, --header or the --proxy-header
options.
If you give an empty argument to -A, --user-agent (""), it removes the
header completely from the request. If you prefer a blank header, you
can set it to a single space (" ").
If -A, --user-agent is provided several times, the last set value is
used.
Example:
curl -A "Agent 007" https://example.com
See also -H, --header and --proxy-header.
-u, --user <user:password>
Specify the user name and password to use for server authentication.
Overrides -n, --netrc and --netrc-optional.
If you simply specify the user name, curl prompts for a password.
The user name and passwords are split up on the first colon, which
makes it impossible to use a colon in the user name with this option.
The password can, still.
On systems where it works, curl hides the given option argument from
process listings. This is not enough to protect credentials from possi‐
bly getting seen by other users on the same system as they still are
visible for a brief moment before cleared. Such sensitive data should
be retrieved from a file instead or similar and never used in clear
text in a command line.
When using Kerberos V5 with a Windows based server you should include
the Windows domain name in the user name, in order for the server to
successfully obtain a Kerberos Ticket. If you do not, then the initial
authentication handshake may fail.
When using NTLM, the user name can be specified simply as the user
name, without the domain, if there is a single domain and forest in
your setup for example.
To specify the domain name use either Down-Level Logon Name or UPN
(User Principal Name) formats. For example, EXAMPLE\user and user@exam‐
ple.com respectively.
If you use a Windows SSPI-enabled curl binary and perform Kerberos V5,
Negotiate, NTLM or Digest authentication then you can tell curl to se‐
lect the user name and password from your environment by specifying a
single colon with this option: "-u :".
If -u, --user is provided several times, the last set value is used.
Example:
curl -u user:secret https://example.com
See also -n, --netrc and -K, --config.
--variable <[%]name=text/@file>
Set a variable with "name=content" or "name@file" (where "file" can be
stdin if set to a single dash (-)). The name is a case sensitive iden‐
tifier that must consist of no other letters than a-z, A-Z, 0-9 or un‐
derscore. The specified content is then associated with this identi‐
fier.
Setting the same variable name again overwrites the old contents with
the new.
The contents of a variable can be referenced in a later command line
option when that option name is prefixed with "--expand-", and the name
is used as "{{name}}" (without the quotes).
--variable can import environment variables into the name space. Opt to
either require the environment variable to be set or provide a default
value for the variable in case it is not already set.
--variable %name imports the variable called 'name' but exits with an
error if that environment variable is not already set. To provide a de‐
fault value if the environment variable is not set, use --variable
%name=content or --variable %name@content. Note that on some systems -
but not all - environment variables are case insensitive.
When expanding variables, curl supports a set of functions that can
make the variable contents more convenient to use. You apply a function
to a variable expansion by adding a colon and then list the desired
functions in a comma-separated list that is evaluated in a
left-to-right order. Variable content holding null bytes that are not
encoded when expanded, causes an error.
Available functions:
trim removes all leading and trailing white space.
json outputs the content using JSON string quoting rules.
url shows the content URL (percent) encoded.
b64 expands the variable base64 encoded
--variable can be used several times in a command line
Example:
curl --variable name=smith https://example.com
See also -K, --config. Added in 8.3.0.
-v, --verbose
Makes curl verbose during the operation. Useful for debugging and see‐
ing what's going on "under the hood". A line starting with '>' means
"header data" sent by curl, '<' means "header data" received by curl
that is hidden in normal cases, and a line starting with '*' means ad‐
ditional info provided by curl.
If you only want HTTP headers in the output, -i, --include or -D,
--dump-header might be more suitable options.
If you think this option still does not give you enough details, con‐
sider using --trace or --trace-ascii instead.
Note that verbose output of curl activities and network traffic might
contain sensitive data, including user names, credentials or secret
data content. Be aware and be careful when sharing trace logs with oth‐
ers.
This option is global and does not need to be specified for each use of
--next.
Providing -v, --verbose multiple times has no extra effect. Disable it
again with --no-verbose.
Example:
curl --verbose https://example.com
See also -i, --include, -s, --silent, --trace and --trace-ascii. This
option is mutually exclusive to --trace and --trace-ascii.
-V, --version
Displays information about curl and the libcurl version it uses.
The first line includes the full version of curl, libcurl and other 3rd
party libraries linked with the executable.
The second line (starts with "Release-Date:") shows the release date.
The third line (starts with "Protocols:") shows all protocols that
libcurl reports to support.
The fourth line (starts with "Features:") shows specific features
libcurl reports to offer. Available features include:
alt-svc
Support for the Alt-Svc: header is provided.
AsynchDNS
This curl uses asynchronous name resolves. Asynchronous name re‐
solves can be done using either the c-ares or the threaded re‐
solver backends.
brotli Support for automatic brotli compression over HTTP(S).
CharConv
curl was built with support for character set conversions (like
EBCDIC)
Debug This curl uses a libcurl built with Debug. This enables more er‐
ror-tracking and memory debugging etc. For curl-developers only!
gsasl The built-in SASL authentication includes extensions to support
SCRAM because libcurl was built with libgsasl.
GSS-API
GSS-API is supported.
HSTS HSTS support is present.
HTTP2 HTTP/2 support has been built-in.
HTTP3 HTTP/3 support has been built-in.
HTTPS-proxy
This curl is built to support HTTPS proxy.
IDN This curl supports IDN - international domain names.
IPv6 You can use IPv6 with this.
Kerberos
Kerberos V5 authentication is supported.
Largefile
This curl supports transfers of large files, files larger than
2GB.
libz Automatic decompression (via gzip, deflate) of compressed files
over HTTP is supported.
MultiSSL
This curl supports multiple TLS backends.
NTLM NTLM authentication is supported.
NTLM_WB
NTLM delegation to winbind helper is supported.
PSL PSL is short for Public Suffix List and means that this curl has
been built with knowledge about "public suffixes".
SPNEGO SPNEGO authentication is supported.
SSL SSL versions of various protocols are supported, such as HTTPS,
FTPS, POP3S and so on.
SSPI SSPI is supported.
TLS-SRP
SRP (Secure Remote Password) authentication is supported for
TLS.
TrackMemory
Debug memory tracking is supported.
Unicode
Unicode support on Windows.
UnixSockets
Unix sockets support is provided.
zstd Automatic decompression (via zstd) of compressed files over HTTP
is supported.
Example:
curl --version
See also -h, --help and -M, --manual.
-w, --write-out <format>
Make curl display information on stdout after a completed transfer. The
format is a string that may contain plain text mixed with any number of
variables. The format can be specified as a literal "string", or you
can have curl read the format from a file with "@filename" and to tell
curl to read the format from stdin you write "@-".
The variables present in the output format are substituted by the value
or text that curl thinks fit, as described below. All variables are
specified as %{variable_name} and to output a normal % you just write
them as %%. You can output a newline by using \n, a carriage return
with \r and a tab space with \t.
The output is by default written to standard output, but can be changed
with %{stderr} and %output{}.
Output HTTP headers from the most recent request by using %header{name}
where name is the case insensitive name of the header (without the
trailing colon). The header contents are exactly as sent over the net‐
work, with leading and trailing whitespace trimmed (added in 7.84.0).
Select a specific target destination file to write the output to, by
using %output{name} (added in curl 8.3.0) where name is the full file
name. The output following that instruction is then written to that
file. More than one %output{} instruction can be specified in the same
write-out argument. If the file name cannot be created, curl leaves the
output destination to the one used prior to the %output{} instruction.
Use %output{>>name} to append data to an existing file.
NOTE: In Windows the %-symbol is a special symbol used to expand envi‐
ronment variables. In batch files all occurrences of % must be doubled
when using this option to properly escape. If this option is used at
the command prompt then the % cannot be escaped and unintended expan‐
sion is possible.
The variables available are:
certs Output the certificate chain with details. Supported
only by the OpenSSL, GnuTLS, Schannel and Secure Trans‐
port backends. (Added in 7.88.0)
content_type The Content-Type of the requested document, if there was
any.
errormsg The error message. (Added in 7.75.0)
exitcode The numerical exit code of the transfer. (Added in
7.75.0)
filename_effective
The ultimate filename that curl writes out to. This is
only meaningful if curl is told to write to a file with
the -O, --remote-name or -o, --output option. It's most
useful in combination with the -J, --remote-header-name
option.
ftp_entry_path The initial path curl ended up in when logging on to the
remote FTP server.
header_json A JSON object with all HTTP response headers from the
recent transfer. Values are provided as arrays, since in
the case of multiple headers there can be multiple val‐
ues. (Added in 7.83.0)
The header names provided in lowercase, listed in order
of appearance over the wire. Except for duplicated head‐
ers. They are grouped on the first occurrence of that
header, each value is presented in the JSON array.
http_code The numerical response code that was found in the last
retrieved HTTP(S) or FTP(s) transfer.
http_connect The numerical code that was found in the last response
(from a proxy) to a curl CONNECT request.
http_version The http version that was effectively used. (Added in
7.50.0)
json A JSON object with all available keys. (Added in 7.70.0)
local_ip The IP address of the local end of the most recently
done connection - can be either IPv4 or IPv6.
local_port The local port number of the most recently done connec‐
tion.
method The http method used in the most recent HTTP request.
(Added in 7.72.0)
num_certs Number of server certificates received in the TLS hand‐
shake. Supported only by the OpenSSL, GnuTLS, Schannel
and Secure Transport backends. (Added in 7.88.0)
num_connects Number of new connects made in the recent transfer.
num_headers The number of response headers in the most recent re‐
quest (restarted at each redirect). Note that the status
line IS NOT a header. (Added in 7.73.0)
num_redirects Number of redirects that were followed in the request.
onerror The rest of the output is only shown if the transfer re‐
turned a non-zero error. (Added in 7.75.0)
proxy_ssl_verify_result
The result of the HTTPS proxy's SSL peer certificate
verification that was requested. 0 means the verifica‐
tion was successful. (Added in 7.52.0)
redirect_url When an HTTP request was made without -L, --location to
follow redirects (or when --max-redirs is met), this
variable shows the actual URL a redirect would have gone
to.
referer The Referer: header, if there was any. (Added in 7.76.0)
remote_ip The remote IP address of the most recently done connec‐
tion - can be either IPv4 or IPv6.
remote_port The remote port number of the most recently done connec‐
tion.
response_code The numerical response code that was found in the last
transfer (formerly known as "http_code").
scheme The URL scheme (sometimes called protocol) that was ef‐
fectively used. (Added in 7.52.0)
size_download The total amount of bytes that were downloaded. This is
the size of the body/data that was transferred, exclud‐
ing headers.
size_header The total amount of bytes of the downloaded headers.
size_request The total amount of bytes that were sent in the HTTP re‐
quest.
size_upload The total amount of bytes that were uploaded. This is
the size of the body/data that was transferred, exclud‐
ing headers.
speed_download The average download speed that curl measured for the
complete download. Bytes per second.
speed_upload The average upload speed that curl measured for the com‐
plete upload. Bytes per second.
ssl_verify_result
The result of the SSL peer certificate verification that
was requested. 0 means the verification was successful.
stderr From this point on, the -w, --write-out output is writ‐
ten to standard error. (Added in 7.63.0)
stdout From this point on, the -w, --write-out output is writ‐
ten to standard output. This is the default, but can be
used to switch back after switching to stderr. (Added
in 7.63.0)
time_appconnect
The time, in seconds, it took from the start until the
SSL/SSH/etc connect/handshake to the remote host was
completed.
time_connect The time, in seconds, it took from the start until the
TCP connect to the remote host (or proxy) was completed.
time_namelookup
The time, in seconds, it took from the start until the
name resolving was completed.
time_pretransfer
The time, in seconds, it took from the start until the
file transfer was just about to begin. This includes all
pre-transfer commands and negotiations that are specific
to the particular protocol(s) involved.
time_redirect The time, in seconds, it took for all redirection steps
including name lookup, connect, pretransfer and transfer
before the final transaction was started. time_redirect
shows the complete execution time for multiple redirec‐
tions.
time_starttransfer
The time, in seconds, it took from the start until the
first byte is received. This includes time_pretransfer
and also the time the server needed to calculate the re‐
sult.
time_total The total time, in seconds, that the full operation
lasted.
url The URL that was fetched. (Added in 7.75.0)
url.scheme The scheme part of the URL that was fetched. (Added in
8.1.0)
url.user The user part of the URL that was fetched. (Added in
8.1.0)
url.password The password part of the URL that was fetched. (Added in
8.1.0)
url.options The options part of the URL that was fetched. (Added in
8.1.0)
url.host The host part of the URL that was fetched. (Added in
8.1.0)
url.port The port number of the URL that was fetched. If no port
number was specified, but the URL scheme is known, that
scheme's default port number is shown. (Added in 8.1.0)
url.path The path part of the URL that was fetched. (Added in
8.1.0)
url.query The query part of the URL that was fetched. (Added in
8.1.0)
url.fragment The fragment part of the URL that was fetched. (Added in
8.1.0)
url.zoneid The zone id part of the URL that was fetched. (Added in
8.1.0)
urle.scheme The scheme part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.user The user part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.password The password part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.options The options part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.host The host part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.port The port number of the effective (last) URL that was
fetched. If no port number was specified, but the URL
scheme is known, that scheme's default port number is
shown. (Added in 8.1.0)
urle.path The path part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.query The query part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.fragment The fragment part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urle.zoneid The zone id part of the effective (last) URL that was
fetched. (Added in 8.1.0)
urlnum The URL index number of this transfer, 0-indexed. Un‐
globbed URLs share the same index number as the origin
globbed URL. (Added in 7.75.0)
url_effective The URL that was fetched last. This is most meaningful
if you have told curl to follow location: headers.
If -w, --write-out is provided several times, the last set value is
used.
Example:
curl -w '%{response_code}\n' https://example.com
See also -v, --verbose and -I, --head.
--xattr
When saving output to a file, this option tells curl to store certain
file metadata in extended file attributes. Currently, the URL is stored
in the xdg.origin.url attribute and, for HTTP, the content type is
stored in the mime_type attribute. If the file system does not support
extended attributes, a warning is issued.
Providing --xattr multiple times has no extra effect. Disable it again
with --no-xattr.
Example:
curl --xattr -o storage https://example.com
See also -R, --remote-time, -w, --write-out and -v, --verbose.
FILES
~/.curlrc
Default config file, see -K, --config for details.
ENVIRONMENT
The environment variables can be specified in lower case or upper case. The
lower case version has precedence. http_proxy is an exception as it is only
available in lower case.
Using an environment variable to set the proxy has the same effect as using
the -x, --proxy option.
http_proxy [protocol://]<host>[:port]
Sets the proxy server to use for HTTP.
HTTPS_PROXY [protocol://]<host>[:port]
Sets the proxy server to use for HTTPS.
[url-protocol]_PROXY [protocol://]<host>[:port]
Sets the proxy server to use for [url-protocol], where the protocol is
a protocol that curl supports and as specified in a URL. FTP, FTPS,
POP3, IMAP, SMTP, LDAP, etc.
ALL_PROXY [protocol://]<host>[:port]
Sets the proxy server to use if no protocol-specific proxy is set.
NO_PROXY <comma-separated list of hosts/domains>
list of host names that should not go through any proxy. If set to an
asterisk '*' only, it matches all hosts. Each name in this list is
matched as either a domain name which contains the hostname, or the
hostname itself.
This environment variable disables use of the proxy even when specified
with the -x, --proxy option. That is NO_PROXY=direct.example.com curl
-x http://proxy.example.com http://direct.example.com accesses the tar‐
get URL directly, and NO_PROXY=direct.example.com curl -x
http://proxy.example.com http://somewhere.example.com accesses the tar‐
get URL through the proxy.
The list of host names can also be include numerical IP addresses, and
IPv6 versions should then be given without enclosing brackets.
IP addresses can be specified using CIDR notation: an appended slash
and number specifies the number of "network bits" out of the address to
use in the comparison (added in 7.86.0). For example "192.168.0.0/16"
would match all addresses starting with "192.168".
APPDATA <dir>
On Windows, this variable is used when trying to find the home direc‐
tory. If the primary home variable are all unset.
COLUMNS <terminal width>
If set, the specified number of characters is used as the terminal
width when the alternative progress-bar is shown. If not set, curl
tries to figure it out using other ways.
CURL_CA_BUNDLE <file>
If set, it is used as the --cacert value.
CURL_HOME <dir>
If set, is the first variable curl checks when trying to find its home
directory. If not set, it continues to check XDG_CONFIG_HOME
CURL_SSL_BACKEND <TLS backend>
If curl was built with support for "MultiSSL", meaning that it has
built-in support for more than one TLS backend, this environment vari‐
able can be set to the case insensitive name of the particular backend
to use when curl is invoked. Setting a name that is not a built-in al‐
ternative makes curl stay with the default.
SSL backend names (case-insensitive): bearssl, gnutls, mbedtls,
openssl, rustls, schannel, secure-transport, wolfssl
HOME <dir>
If set, this is used to find the home directory when that is needed.
Like when looking for the default .curlrc. CURL_HOME and XDG_CON‐
FIG_HOME have preference.
QLOGDIR <directory name>
If curl was built with HTTP/3 support, setting this environment vari‐
able to a local directory makes curl produce qlogs in that directory,
using file names named after the destination connection id (in hex). Do
note that these files can become rather large. Works with the ngtcp2
and quiche QUIC backends.
SHELL Used on VMS when trying to detect if using a DCL or a unix shell.
SSL_CERT_DIR <dir>
If set, it is used as the --capath value.
SSL_CERT_FILE <path>
If set, it is used as the --cacert value.
SSLKEYLOGFILE <file name>
If you set this environment variable to a file name, curl stores TLS
secrets from its connections in that file when invoked to enable you to
analyze the TLS traffic in real time using network analyzing tools such
as Wireshark. This works with the following TLS backends: OpenSSL, li‐
bressl, BoringSSL, GnuTLS and wolfSSL.
USERPROFILE <dir>
On Windows, this variable is used when trying to find the home direc‐
tory. If the other, primary, variable are all unset. If set, curl uses
the path "$USERPROFILE\Application Data".
XDG_CONFIG_HOME <dir>
If CURL_HOME is not set, this variable is checked when looking for a
default .curlrc file.
PROXY PROTOCOL PREFIXES
The proxy string may be specified with a protocol:// prefix to specify alter‐
native proxy protocols.
If no protocol is specified in the proxy string or if the string does not
match a supported one, the proxy is treated as an HTTP proxy.
The supported proxy protocol prefixes are as follows:
http://
Makes it use it as an HTTP proxy. The default if no scheme prefix is
used.
https://
Makes it treated as an HTTPS proxy.
socks4://
Makes it the equivalent of --socks4
socks4a://
Makes it the equivalent of --socks4a
socks5://
Makes it the equivalent of --socks5
socks5h://
Makes it the equivalent of --socks5-hostname
EXIT CODES
There are a bunch of different error codes and their corresponding error mes‐
sages that may appear under error conditions. At the time of this writing, the
exit codes are:
0 Success. The operation completed successfully according to the instruc‐
tions.
1 Unsupported protocol. This build of curl has no support for this proto‐
col.
2 Failed to initialize.
3 URL malformed. The syntax was not correct.
4 A feature or option that was needed to perform the desired request was
not enabled or was explicitly disabled at build-time. To make curl able
to do this, you probably need another build of libcurl.
5 Could not resolve proxy. The given proxy host could not be resolved.
6 Could not resolve host. The given remote host could not be resolved.
7 Failed to connect to host.
8 Weird server reply. The server sent data curl could not parse.
9 FTP access denied. The server denied login or denied access to the par‐
ticular resource or directory you wanted to reach. Most often you tried
to change to a directory that does not exist on the server.
10 FTP accept failed. While waiting for the server to connect back when an
active FTP session is used, an error code was sent over the control
connection or similar.
11 FTP weird PASS reply. Curl could not parse the reply sent to the PASS
request.
12 During an active FTP session while waiting for the server to connect
back to curl, the timeout expired.
13 FTP weird PASV reply, Curl could not parse the reply sent to the PASV
request.
14 FTP weird 227 format. Curl could not parse the 227-line the server
sent.
15 FTP cannot use host. Could not resolve the host IP we got in the
227-line.
16 HTTP/2 error. A problem was detected in the HTTP2 framing layer. This
is somewhat generic and can be one out of several problems, see the er‐
ror message for details.
17 FTP could not set binary. Could not change transfer method to binary.
18 Partial file. Only a part of the file was transferred.
19 FTP could not download/access the given file, the RETR (or similar)
command failed.
21 FTP quote error. A quote command returned error from the server.
22 HTTP page not retrieved. The requested URL was not found or returned
another error with the HTTP error code being 400 or above. This return
code only appears if -f, --fail is used.
23 Write error. Curl could not write data to a local filesystem or simi‐
lar.
25 Failed starting the upload. For FTP, the server typically denied the
STOR command.
26 Read error. Various reading problems.
27 Out of memory. A memory allocation request failed.
28 Operation timeout. The specified time-out period was reached according
to the conditions.
30 FTP PORT failed. The PORT command failed. Not all FTP servers support
the PORT command, try doing a transfer using PASV instead!
31 FTP could not use REST. The REST command failed. This command is used
for resumed FTP transfers.
33 HTTP range error. The range "command" did not work.
34 HTTP post error. Internal post-request generation error.
35 SSL connect error. The SSL handshaking failed.
36 Bad download resume. Could not continue an earlier aborted download.
37 FILE could not read file. Failed to open the file. Permissions?
38 LDAP cannot bind. LDAP bind operation failed.
39 LDAP search failed.
41 Function not found. A required LDAP function was not found.
42 Aborted by callback. An application told curl to abort the operation.
43 Internal error. A function was called with a bad parameter.
45 Interface error. A specified outgoing interface could not be used.
47 Too many redirects. When following redirects, curl hit the maximum
amount.
48 Unknown option specified to libcurl. This indicates that you passed a
weird option to curl that was passed on to libcurl and rejected. Read
up in the manual!
49 Malformed telnet option.
52 The server did not reply anything, which here is considered an error.
53 SSL crypto engine not found.
54 Cannot set SSL crypto engine as default.
55 Failed sending network data.
56 Failure in receiving network data.
58 Problem with the local certificate.
59 Could not use specified SSL cipher.
60 Peer certificate cannot be authenticated with known CA certificates.
61 Unrecognized transfer encoding.
63 Maximum file size exceeded.
64 Requested FTP SSL level failed.
65 Sending the data requires a rewind that failed.
66 Failed to initialize SSL Engine.
67 The user name, password, or similar was not accepted and curl failed to
log in.
68 File not found on TFTP server.
69 Permission problem on TFTP server.
70 Out of disk space on TFTP server.
71 Illegal TFTP operation.
72 Unknown TFTP transfer ID.
73 File already exists (TFTP).
74 No such user (TFTP).
77 Problem reading the SSL CA cert (path? access rights?).
78 The resource referenced in the URL does not exist.
79 An unspecified error occurred during the SSH session.
80 Failed to shut down the SSL connection.
82 Could not load CRL file, missing or wrong format.
83 Issuer check failed.
84 The FTP PRET command failed.
85 Mismatch of RTSP CSeq numbers.
86 Mismatch of RTSP Session Identifiers.
87 Unable to parse FTP file list.
88 FTP chunk callback reported error.
89 No connection available, the session is queued.
90 SSL public key does not matched pinned public key.
91 Invalid SSL certificate status.
92 Stream error in HTTP/2 framing layer.
93 An API function was called from inside a callback.
94 An authentication function returned an error.
95 A problem was detected in the HTTP/3 layer. This is somewhat generic
and can be one out of several problems, see the error message for de‐
tails.
96 QUIC connection error. This error may be caused by an SSL library er‐
ror. QUIC is the protocol used for HTTP/3 transfers.
97 Proxy handshake error.
98 A client-side certificate is required to complete the TLS handshake.
99 Poll or select returned fatal error.
XX More error codes might appear here in future releases. The existing
ones are meant to never change.
BUGS
If you experience any problems with curl, submit an issue in the project's bug
tracker on GitHub: https://github.com/curl/curl/issues
AUTHORS / CONTRIBUTORS
Daniel Stenberg is the main author, but the whole list of contributors is
found in the separate THANKS file.
WWW
https://curl.se
SEE ALSO
ftp(1), wget(1)
curl 8.5.0 December 05 2023 curl(1)
Generated 2026-11-02 from the manual installed on node.spa-dev-dh.xyz. Original copyright and license terms apply.