Provided by: curl_7.81.0-1ubuntu1.19_amd64 
NAME
curl - transfer a URL
SYNOPSIS
curl [options / URLs]
DESCRIPTION
curl is a tool for transferring data from or to a server. It supports 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 or TFTP. The command
is designed to work without user interaction.
curl offers a busload of useful tricks like proxy support, user authentication, FTP
upload, HTTP post, SSL connections, cookies, file transfer resume and more. As you will
see below, the number of features will make your head spin.
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.
You can specify multiple URLs or parts of URLs by writing part sets within braces and
quoting the URL as in:
"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 any amount of URLs on the command line. They will be fetched in a
sequential manner in the specified order. You can specify command line options and URLs
mixed and in any order on the command line.
You can specify a step counter for the ranges to get every Nth number or letter:
"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 '*'.
Provide the IPv6 zone index in the URL with an escaped percentage sign and the interface
name. Like in
"http://[fe80::3%25eth0]/"
If you specify URL without protocol:// prefix, curl will attempt to guess what protocol
you might want. It will then default to HTTP but try other protocols based on often-used
host name prefixes. For example, for host names starting with "ftp." curl will assume you
want to speak FTP.
curl will do its best to use what you pass to it as a URL. It is not trying to validate it
as a syntactically correct URL by any means but is fairly liberal with what it accepts.
curl will attempt to re-use connections for multiple file transfers, so that getting many
files from the same server will not do multiple connects / handshakes. This improves
speed. Of course this is only done on files specified on a single command line and cannot
be used between separate curl invocations.
OUTPUT
If not told otherwise, curl writes the received data to stdout. It can be instructed 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 dedicated command line
options.
PROTOCOLS
curl supports numerous protocols, or put in URL terms: schemes. Your particular 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 will work.
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 server 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 number of bytes and the speeds are 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 redirect 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 response 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 completely with the -s, --silent option.
OPTIONS
Options start with one or two dashes. Many of the options require an additional value next
to them.
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 immediately 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 disabled 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.
--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 prefixed with '@',
however the <path> argument should not have this leading character.
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 will be used. After a completed transfer, the
cache will be 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 will load contents from all the files
but the last one will be used for saving.
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 possibly inducing an extra network round-
trip. This is used instead of setting 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 upload operation will fail.
Used together with -u, --user.
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 makes curl append to the target file
instead of overwriting it. If the remote file does not exist, it will be created.
Note that this flag is ignored by some SFTP servers (including OpenSSH).
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 endpoint.
Example:
curl --aws-sigv4 "aws:amz: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.
Example:
curl -u name:password --basic https://example.com
See also --proxy-basic.
--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 option overrides that
variable.
The windows version of curl will automatically look 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.
If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module
(libnsspem.so) needs to be available for this option to work properly.
(iOS and macOS only) If curl is built against Secure Transport, then this option is
supported for backward compatibility with other SSL engines, but it should not be
set. If the option is not set, then curl will use 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 with
libcurl 7.60 or later. This option is supported for backward compatibility with
other SSL engines; instead it is recommended to use Windows' store of root
certificates (the default for Schannel).
If this option is used several times, the last one will be 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 --capath 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 will be ignored, and if it is used
several times, the last one will be 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 using the
Certificate Status Request (aka. OCSP stapling) TLS extension.
If this option is enabled and the server sends an invalid (e.g. expired) 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, GnuTLS and NSS backends.
Example:
curl --cert-status https://example.com
See also --pinnedpubkey. Added in 7.41.0.
--cert-type <type>
(TLS) Tells curl what type the provided client certificate is using. PEM, DER, ENG
and P12 are recognized types. If not specified, PEM is assumed.
If this option is used several times, the last one will be 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 getting a file
with HTTPS, FTPS or another SSL-based protocol. The certificate must be in PKCS#12
format if using Secure Transport, or PEM format if using any other engine. If the
optional password is not specified, it will be 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.
If curl is built against the NSS SSL library then this option can tell curl the
nickname of the certificate to use within the NSS database defined by the
environment variable SSL_DIR (or by default /etc/pki/nssdb). If the NSS PEM PKCS#11
module (libnsspem.so) is available then PEM files may be loaded. If you want to use
a file from the current directory, please precede it with "./" prefix, in order to
avoid confusion with a nickname. If the nickname contains ":", it needs to be
preceded by "\" so that it is not recognized as password delimiter. If the nickname
contains "\", it needs to be escaped 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 certificate located in a PKCS#11
device. A string beginning with "pkcs11:" will be interpreted as a PKCS#11 URI. If
a PKCS#11 URI is provided, then the --engine option will be set as "pkcs11" if none
was provided and the --cert-type option will be 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 confusion with a nickname.
(Schannel only) Client certificates must be specified by a path expression to a
certificate store. (Loading PFX is not supported; you can import it to a store
first). You can use "<store location>\<store name>\<thumbprint>" to refer to a
certificate in the system certificates store, for example,
"CurrentUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a". Thumbprint is usually a
SHA-1 hex string which you can see in certificate details. Following store
locations are supported: CurrentUser, LocalMachine, CurrentService, Services,
CurrentUserGroupPolicy, LocalMachineGroupPolicy, LocalMachineEnterprise.
If this option is used several times, the last one will be 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 ciphers must
specify valid ciphers. Read up on SSL cipher list details on this URL:
https://curl.se/docs/ssl-ciphers.html
If this option is used several times, the last one will be used.
Example:
curl --ciphers ECDHE-ECDSA-AES256-CCM8 https://example.com
See also --tlsv1.3.
--compressed-ssh
(SCP SFTP) Enables built-in SSH compression. This is a request, not an order; the
server may or may not do it.
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. Headers are not modified.
If this option is used and the server sends an unsupported encoding, curl will
report an error. This is a request, not an order; the server may or may not deliver
data 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 arguments found
in the text file will be 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 parameter.
If the parameter contains whitespace (or starts with : or =), the parameter must be
enclosed within 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 column of a config line is a '#' character, the rest of the line will
be treated as a comment.
Only write one option per physical line in the config file.
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.
This option can be used multiple times to load multiple config files.
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 will continue
- if not it will exit. Since version 7.32.0, this option accepts decimal values.
If this option is used several times, the last one will be 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 instead. 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, certificate 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 original 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".
This option can be used many times to add many connect rules.
Example:
curl --connect-to example.com:443:example.net:8443 https://example.com
See also --resolve and -H, --header. Added in 7.49.0.
-C, --continue-at <offset>
Continue/Resume a previous file transfer at the given offset. The given offset is
the exact number of bytes that will be skipped, counting from the beginning of the
source file before it is transferred to the destination. If used with uploads, the
FTP server command SIZE will not be 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 this option is used several times, the last one will be 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 will be written.
The file will be written using the Netscape cookie file format. If you set the file
name to a single dash, "-", the cookies will be written to stdout.
This command line option will activate the cookie engine that makes curl record and
use cookies. Another way to activate it is to use the -b, --cookie option.
If the cookie jar cannot be created or written to, the whole curl operation will
not fail or even report an error clearly. Using -v, --verbose will get a warning
displayed, but that is the only visible feedback you get about this possibly lethal
situation.
If this option is used several times, the last specified file name will be 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".
If no '=' symbol is used in the argument, it is instead treated as a filename to
read previously stored cookie from. This option also activates the cookie engine
which will make curl record incoming cookies, which may be handy if you are using
this in combination with the -L, --location option or do multiple URL transfers on
the same invoke. If the file name is exactly a minus ("-"), curl will instead read
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 will be
written to the file. To store cookies, use the -c, --cookie-jar option.
If you use the Set-Cookie file format and do not specify a domain then the cookie
is not sent since the domain will never match. To address this, set a domain in
Set-Cookie line (doing that will include sub-domains) or preferably: use the
Netscape format.
This option can be used multiple times.
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.
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 will create the
necessary local directory hierarchy as needed. This option creates the directories
mentioned with the -o, --output option, nothing else. If the --output file name
uses no directory, or if the directories it mentions already exist, no directories
will be created.
Created dirs are made with mode 0750 on unix style file systems.
To create remote directories when using FTP or SFTP, try --ftp-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 this option is used several times, the last one will be 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 LF to CRLF in upload. Useful for MVS (OS/390).
(SMTP added in 7.40.0)
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 revoked.
If this option is used several times, the last one will be 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 parameter is available identically in the
"openssl s_client/s_server" utilities.
--curves allows a OpenSSL powered curl to make SSL-connections with exactly the
(EC) curve requested by the client, avoiding nontransparent client/server
negotiations.
If this option is set, the default curves list built into openssl will be ignored.
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.
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 newlines and carriage
returns are preserved and conversions are never done.
Like -d, --data the default content-type sent to the server is application/x-www-
form-urlencoded. If you want the data to be treated as arbitrary 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 will append data
as described in -d, --data.
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.
Examples:
curl --data-raw "hello" https://example.com
curl --data-raw "@at@at@" https://example.com
See also -d, --data. Added in 7.43.0.
--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 will make curl URL-encode the content and pass that on. Just be careful
so that the content does not contain any = or @ symbols, as that will then
make the syntax match one of the other cases below!
=content
This will make curl URL-encode the content and pass that on. The preceding =
symbol is not included in the data.
name=content
This will make curl URL-encode the content part and pass that on. Note that
the name part is expected to be URL-encoded already.
@filename
This will make curl load data from the given file (including any newlines),
URL-encode that data and pass it on in the POST.
name@filename
This will make 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=urlencoded-file-content. Note that the name
is expected to be URL-encoded already.
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 will cause curl to pass the data to the server using the
content-type application/x-www-form-urlencoded. Compare to -F, --form.
--data-raw is almost the same but does not have a special interpretation 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 will be 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 will be stripped
out. If you do not want the @ character to have a special interpretation use
--data-raw instead.
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 overrides -F,
--form and -I, --head and -T, --upload-file.
--delegation <LEVEL>
(GSS/kerberos) Set LEVEL to tell the server what it is allowed to delegate 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 this option is used several times, the last one will be 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.
If this option is used several times, only the first one is used.
Example:
curl -u name:password --digest https://example.com
See also -u, --user, --proxy-digest and --anyauth. This option overrides --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 will normally always first attempt to use EPRT, then LPRT
before using PORT, but with this option, it will use PORT right away. EPRT and LPRT
are extensions to the original FTP protocol, and may not work on all servers, but
they enable more functionality in a better way than the traditional 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 will have 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.
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 passive FTP
transfers. Curl will normally always first attempt to use EPSV before PASV, but
with this option, it will not try using 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 will have 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.
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 will not
be read and used. See the -K, --config for details on the default config file
search path.
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 run-time or similar.
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).
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. Added in 7.33.0.
--dns-ipv4-addr <address>
(DNS) Tell curl to bind to <ip-address> when making IPv4 DNS requests, so that the
DNS requests originate from this address. The argument should be a single IPv4
address.
If this option is used several times, the last one will be 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. Added in 7.33.0.
--dns-ipv6-addr <address>
(DNS) Tell curl to bind to <ip-address> when making IPv6 DNS requests, so that the
DNS requests originate from this address. The argument should be a single IPv6
address.
If this option is used several times, the last one will be 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. Added in 7.33.0.
--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 this option is used several times, the last one will be 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. Added in 7.33.0.
--doh-cert-status
Same as --cert-status but used for DoH (DNS-over-HTTPS).
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).
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 hostnames, instead of
using the default name resolver mechanism. The URL must be HTTPS.
Some SSL options that you set for your transfer will apply to DoH since the name
lookups take place over SSL. However, the certificate verification settings are not
inherited and can be controlled separately via --doh-insecure and --doh-cert-
status.
If this option is used several times, the last one will be 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 will create an empty file.
When used in FTP, the FTP server response lines are considered being "headers" and
thus are saved there.
If this option is used several times, the last one will be used.
Example:
curl --dump-header store.txt https://example.com
See also -o, --output.
--egd-file <file>
(TLS) Specify the path name to the Entropy Gathering Daemon socket. The socket is
used to seed the random engine for SSL connections.
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 run-time.
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.
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.
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 will wait one second. This option accepts decimal values! When curl stops
waiting, it will continue as if the response has been received.
Example:
curl --expect100-timeout 2.5 -T file https://example.com
See also --connect-timeout. Added in 7.47.0.
--fail-early
Fail and exit on the first detected transfer error.
When curl is used to do multiple transfers on the command line, it will attempt to
operate on each given URL, one by one. By default, it will ignore errors if there
are more URLs given and the last URL's success will determine the error code curl
returns. So early failures will be "hidden" by subsequent successful transfers.
Using this option, curl will instead return 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 is global and does not need to be specified for each use of -:, --next.
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.
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 describes why and more). This
flag will still allow 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.
Example:
curl --fail-with-body https://example.com
See also -f, --fail. Added in 7.76.0.
-f, --fail
(HTTP) Fail silently (no output at all) on server errors. This is mostly done to
enable scripts etc to better deal with failed attempts. In normal cases when an
HTTP server fails to deliver a document, it returns an HTML document stating so
(which often also describes why and more). This flag will prevent curl from
outputting that and return error 22.
This method is not fail-safe and there are occasions where non-successful response
codes will slip through, especially when authentication is involved (response codes
401 and 407).
Example:
curl --fail https://example.com
See also --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 will start sending application data before verifying the
server's Finished message, thus saving a round trip when performing a full
handshake.
This is currently only implemented in the NSS and Secure Transport (on iOS 7.0 or
later, or OS X 10.9 or later) backends.
Example:
curl --false-start https://example.com
See also --tcp-fastopen. Added in 7.42.0.
--form-escape
(HTTP) Tells curl to pass on names of multipart form fields and files using
backslash-escaping instead of percent-encoding.
Example:
curl --form-escape --form 'field\name=curl' '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's any possibility that the string value may accidentally trigger the '@'
or '<' features of -F, --form.
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 according 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 content part from a
file, prefix the file name with the symbol <. The difference 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
unfortunately not subject to buffering and will be effectively 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 will be 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 double-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 double-quote or
backslash within the filename must be escaped by backslash.
Quoting must also be applied to non-file data if it contains semicolons,
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 argument,
- 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 attaches 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 characters 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.
This option can be used multiple times.
Example:
curl --form "name=curl" --form "file=@loadthis" https://example.com
See also -d, --data, --form-string and --form-escape. This option overrides -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 command.
If this option is used several times, the last one will be 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" will tell the server to retrieve the username from
the certificate.
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 will instead attempt to create missing directories.
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 alternatives:
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 will do 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 operates on the
file "normally" (like in the multicwd case). This is somewhat more standards
compliant than 'nocwd' but without the full penalty of 'multicwd'.
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 previous -P, --ftp-port
option.
If this option is used several times, only the first one is used. Undoing an
enforced passive really is not doable but you must then instead enforce the correct
-P, --ftp-port again.
Passive mode means that curl will try the EPSV command first and then PASV, unless
--disable-epsv is used.
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
If this option is used several times, the last one will be used. 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.
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 directory listings as well as
up and downloads in PASV mode.
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 will re-
use the same IP address it already uses for the control connection.
Since curl 7.74.0 this option is enabled by default.
This option has no effect if PORT, EPRT or EPSV is used instead of PASV.
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 will not initiate the shutdown, but
instead wait for the server to do it, and will not reply to the shutdown from the
server. The active mode initiates the shutdown and waits for a reply from the
server.
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 after
authenticating. The rest of the control channel communication will be unencrypted.
This allows NAT routers to follow the FTP transaction. The default mode is passive.
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.
Example:
curl --ftp-ssl-control ftp://example.com
See also --ssl.
-G, --get
When used, this option will make all data specified with -d, --data, --data-binary
or --data-urlencode to be used in an HTTP GET request instead of the POST request
that otherwise would be used. The data will be appended to the URL with a '?'
separator.
If used in combination with -I, --head, the POST data will instead be appended to
the URL with a HEAD request.
If this option is used several times, only the first one is used. This is because
undoing a GET does not make sense, but you should then instead enforce the
alternative method you prefer.
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 having curl itself interpret
them. Note that these letters are not normal legal URL contents but they should be
encoded according to the URI standard.
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 currently defaults to 200 ms. Firefox and
Chrome currently default to 300 ms.
If this option is used several times, the last one will be 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-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.
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 command 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.
Example:
curl -I https://example.com
See also -G, --get, -v, --verbose and --trace-ascii.
-H, --header <header/@file>
(HTTP) Extra header to include in the request when sending HTTP to a server. 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 will be used instead of the internal 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-Custom-Header;" to send
"X-Custom-Header:".
curl will make 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 will only mess things up for you.
This option can take an argument in @filename style, which then adds a header for
each line in the input file. Using @- will make curl read the header file from
stdin. Added in 7.55.0.
You need --proxy-header to send custom headers intended for a HTTP proxy. Added in
7.37.0.
Passing on a "Transfer-Encoding: chunked" header when doing a HTTP request with a
request body, will make curl send the data using chunked encoding.
WARNING: headers set with this option will be set in all 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.
This option can be used multiple times to add/replace/remove multiple headers.
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
See also -A, --user-agent and -e, --referer.
-h, --help <category>
Usage help. This lists all commands of the <category>. If no arg was provided,
curl will display the most important command line arguments. If the argument "all"
was provided, curl will display all options available. If the argument "category"
was provided, curl will display all categories and their meanings.
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 will refuse the
connection with the host unless the md5sums match.
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 will refuse the connection with the host unless the hashes
match.
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 will be used. After a completed transfer, the cache
will be 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 HSTS in memory.
If this option is used several times, curl will load contents from all the files
but the last one will be used for saving.
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 completely headerless response and therefore you can also connect
with this to non-HTTP servers and still get a response since curl will simply
transparently downgrade - if allowed.
Since curl 7.66.0, HTTP/0.9 is disabled by default.
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 internally preferred
HTTP version.
Example:
curl --http1.0 https://example.com
See also --http0.9 and --http1.1. This option overrides --http1.1 and --http2.
--http1.1
(HTTP) Tells curl to use HTTP version 1.1.
Example:
curl --http1.1 https://example.com
See also --http1.1 and --http0.9. This option overrides -0, --http1.0 and --http2.
Added in 7.33.0.
--http2-prior-knowledge
(HTTP) Tells curl to issue its non-TLS HTTP requests using HTTP/2 without HTTP/1.1
Upgrade. It requires prior knowledge that the server supports HTTP/2 straight away.
HTTPS requests will still do HTTP/2 the standard way with negotiated protocol
version in the TLS handshake.
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 overrides --http1.1 and -0,
--http1.0 and --http2. Added in 7.49.0.
--http2
(HTTP) Tells curl to use HTTP version 2.
For HTTPS, this means curl will attempt to negotiate HTTP/2 in the TLS handshake.
curl does this by default.
For HTTP, this means curl will attempt to upgrade the request to HTTP/2 using the
Upgrade: request header.
Example:
curl --http2 https://example.com
See also --http1.1 and --http3. --http2 requires that the underlying libcurl was
built to support HTTP/2. This option overrides --http1.1 and -0, --http1.0 and
--http2-prior-knowledge. Added in 7.33.0.
--http3
(HTTP) WARNING: this option is experimental. Do not use in production.
Tells curl to use HTTP version 3 directly to the host and port number used in the
URL. A normal HTTP/3 transaction will be done to a host and then get redirected via
Alt-Svc, but this option allows a user to circumvent that when you know that the
target speaks HTTP/3 on the given host and port.
This option will make curl fail if a QUIC connection cannot be established, it
cannot fall back to a lower HTTP version on its own.
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 overrides --http1.1 and -0, --http1.0 and
--http2 and --http2-prior-knowledge. Added in 7.66.0.
--ignore-content-length
(FTP HTTP) For HTTP, Ignore the Content-Length header. This is particularly useful
for servers running Apache 1.x, which will report incorrect Content-Length for
files larger than 2 gigabytes.
For FTP (since 7.46.0), skip the RETR command to figure out the size before
downloading a file.
This option does not work for HTTP if libcurl was built to use hyper.
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 document, HTTP version and
more...
To view the request headers, consider the -v, --verbose option.
Example:
curl -i https://example.com
See also -v, --verbose.
-k, --insecure
(TLS SFTP SCP) By default, every secure connection curl makes is verified 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 contains 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 verification.
known_hosts is a file normally stored in the user's home directory in the .ssh
subdirectory, which contains host names and their public keys.
WARNING: using this option makes the transfer 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 interface name, IP
address or host name. An example could look like:
curl --interface eth0:1 https://www.example.com/
If this option is used several times, the last one will be used.
On Linux it can be used to specify a VRF, but the binary needs to either have
CAP_NET_RAW or to be run as root. More information about Linux VRF:
https://www.kernel.org/doc/Documentation/networking/vrf.txt
Example:
curl --interface eth0 https://example.com
See also --dns-interface.
-4, --ipv4
This option tells curl to resolve names to IPv4 addresses only, and not for example
try IPv6.
Example:
curl --ipv4 https://example.com
See also --http1.1 and --http2. This option overrides -6, --ipv6.
-6, --ipv6
This option tells curl to resolve names to IPv6 addresses only, and not for example
try IPv4.
Example:
curl --ipv6 https://example.com
See also --http1.1 and --http2. This option overrides -4, --ipv4.
-j, --junk-session-cookies
(HTTP) When curl is told to read cookies from a given file, this option will make
it discard all "session cookies". This will basically have the same effect as if a
new session is started. Typical browsers always discard session cookies when they
are closed down.
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). This option has no effect if
--no-keepalive is used.
If this option is used several times, the last one will be used. If unspecified,
the option defaults to 60 seconds.
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 this option is used several times, the last one will be 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 following 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 private key located in a PKCS#11
device. A string beginning with "pkcs11:" will be interpreted as a PKCS#11 URI. If
a PKCS#11 URI is provided, then the --engine option will be set as "pkcs11" if none
was provided and the --key-type option will be set as "ENG" if none was provided.
If this option is used several times, the last one will be 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' will instead be used.
If this option is used several times, the last one will be 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 will get libcurl-
using C source code written to the file that does the equivalent of what your
command-line operation does!
This option is global and does not need to be specified for each use of -:, --next.
If this option is used several times, the last given file name will be 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 downloads 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 appended.
Appending 'k' or 'K' will count the number as kilobytes, 'm' or 'M' makes it
megabytes, while 'g' or 'G' makes it gigabytes. The suffixes (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 will take precedence and
might cripple the rate-limiting slightly, to help keeping the speed-limit logic
working.
If this option is used several times, the last one will be 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 -Y, --speed-limit and -y, --speed-time.
-l, --list-only
(FTP POP3) (FTP) When listing an FTP directory, this switch forces a name-only
view. This is especially useful if the user wants to machine-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.
(POP3) When retrieving a specific email from POP3, this switch forces a LIST
command to be performed instead of RETR. This is particularly useful 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 identifier rather than its
message-id to make the request.
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 that
will be busy at times so setting this range to something too narrow might cause
unnecessary connection setup failures.
Example:
curl --local-port 1000-3000 https://example.com
See also -g, --globoff.
--location-trusted
(HTTP) Like -L, --location, but will allow 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 will send your authentication info
(which is plaintext in the case of HTTP Basic authentication).
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 response code), this option
will make curl redo the request on the new place. If used together with -i,
--include or -I, --head, headers from all requested pages will be shown. When
authentication is used, curl only sends its credentials to the initial host. If a
redirect takes curl to a different host, it will not be able to intercept the
user+password. See also --location-trusted on how to change this. You can limit the
amount of redirects to follow by using the --max-redirs option.
When curl follows a redirect and if the request is a POST, it will send 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 will re-send the following request using
the same unmodified method.
You can tell curl to not change POST requests to GET after a 30x response by using
the dedicated options for that: --post301, --post302 and --post303.
The method set with -X, --request overrides the method curl would otherwise select
to use.
Example:
curl -L https://example.com
See also --resolve and --alt-svc.
--login-options <options>
(IMAP 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 support login options.
For more information about login options please see RFC 2384, RFC 5092 and IETF
draft draft-earhart-url-smtp-00.txt
If this option is used several times, the last one will be used.
Example:
curl --login-options 'AUTH=*' imap://example.com
See also -u, --user. Added in 7.34.0.
--mail-auth <address>
(SMTP) Specify a single address. This will be used to specify the authentication
address (identity) of a submitted message that is being relayed to another server.
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.
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 will abort SMTP
conversation if at least one of the recipients causes RCPT TO command to return an
error.
The default behavior can be changed by passing --mail-rcpt-allowfails command-line
option which will make curl ignore errors and proceed with the remaining valid
recipients.
If all recipients trigger RCPT TO failures and this flag is specified, curl will
still abort the SMTP conversation and return the error received from to the last
RCPT TO command.
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 RFC5321).
(Added in 7.34.0)
When performing a mailing list expand (EXPN command), the recipient should be
specified using the mailing list name, such as "Friends" or "London-Office".
(Added in 7.34.0)
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 download. If the
file requested is larger than this value, the transfer will not start and curl will
return with exit code 63.
A size modifier may be used. For example, Appending 'k' or 'K' will count 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: The file size is not always known prior to download, and for such files this
option has no effect even if the file transfer ends up being larger than this given
limit. 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, --location is used,
to prevent curl from following too many redirects, by default, the limit is set to
50 redirects. Set this option to -1 to make it unlimited.
If this option is used several times, the last one will be 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 the whole operation to take. This is useful
for preventing your batch jobs from hanging for hours due to slow networks or links
going down. Since 7.32.0, this option accepts decimal values, but the actual
timeout will decrease in accuracy as the specified timeout increases in decimal
precision.
If this option is used several times, the last one will be used.
Examples:
curl --max-time 10 https://example.com
curl --max-time 2.92 https://example.com
See also --connect-timeout.
--metalink
This option was previously used to specify a metalink resource. Metalink support
has been disabled in curl since 7.78.0 for security reasons.
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.
If this option is used several times, only the first one is used.
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. If several --netrc-file options are provided, the last one
will be used.
It will abide by --netrc-optional if specified.
Example:
curl --netrc-file netrc https://example.com
See also -n, --netrc, -u, --user and -K, --config. This option overrides -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.
Example:
curl --netrc-optional https://example.com
See also --netrc-file. This option overrides -n, --netrc.
-n, --netrc
Makes curl scan the .netrc (_netrc on Windows) 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 will enable user authentication. See netrc(5) and ftp(1) for details on
the file format. Curl will not complain if that file does not have the right
permissions (it should be neither world- nor group-readable). The environment
variable "HOME" is used to find the home directory.
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"
Example:
curl --netrc https://example.com
See also --netrc-file, -K, --config and -u, --user.
-:, --next
Tells curl to use a separate operation for the following URL and associated
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 will reset all local options and only global ones will have their values
survive over to the operation following the -:, --next instruction. 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
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. Added in 7.36.0.
--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.
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. Added in 7.36.0.
-N, --no-buffer
Disables the buffering of the output stream. In normal work situations, curl will
use a standard buffered output stream that will have the effect that it will output
the data in chunks, not necessarily exactly when the data arrives. Using this
option will disable that buffering.
Note that this is the negated option name documented. You can thus use --buffer to
enforce the buffering.
Example:
curl --no-buffer https://example.com
See also -#, --progress-bar.
--no-keepalive
Disables the use of keepalive messages on the TCP connection. curl otherwise
enables them by default.
Note that this is the negated option name documented. You can thus use --keepalive
to enforce keepalive.
Example:
curl --no-keepalive https://example.com
See also --keepalive-time.
--no-npn
(HTTPS) 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.
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. Added in 7.36.0.
--no-progress-meter
Option to switch off the progress meter output without muting or otherwise
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.
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 broken 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.
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.
Since 7.53.0, This option overrides the environment variables that disable the
proxy ('no_proxy' and 'NO_PROXY'). If there's an environment variable disabling a
proxy, you can set the noproxy list to "" to override it.
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 executed when needed.
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 proprietary protocol, reverse-
engineered by clever people and implemented in curl based on their efforts. This
kind of behavior should not be endorsed, you should encourage everyone who uses
NTLM to switch to a public and documented authentication method instead, such as
Digest.
If you want to enable NTLM for your proxy authentication, then use --proxy-ntlm.
If this option is used several times, only the first one is used.
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 overrides --basic and --negotiate and --digest and
--anyauth.
--oauth2-bearer <token>
(IMAP 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 options.
The Bearer Token and user name are formatted according to RFC 6750.
If this option is used several times, the last one will be used.
Example:
curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com
See also --basic, --ntlm and --digest. Added in 7.33.0.
--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 will fail unless
--create-dirs is also used.
If this option is used multiple times, the last specified directory will be 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 will be 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].com" -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 dynamically.
Specifying the output as '-' (a single dash) will force the output to be done to
stdout.
To suppress response bodies, you can redirect output to /dev/null:
curl example.com -o /dev/null
Or for Windows use nul:
curl example.com -o nul
Examples:
curl -o file https://example.com
curl "http://{one,two}.example.com" -o "file_#1.txt"
curl "http://{site,host}.host[1-5].com" -o "#1_#2"
curl -o file https://example.com -o file2 https://example.net
See also -O, --remote-name, --remote-name-all and -J, --remote-header-name.
--parallel-immediate
When doing parallel transfers, this option will instruct 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.
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.
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.
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 this option is used several times, the last one will be 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 will squash or merge them according to standards but with this option set you
tell it not to do that.
Example:
curl --path-as-is https://example.com/../../etc/passwd
See also --request-target. Added in 7.42.0.
--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 certificate indicating
its identity. A public key is extracted from this certificate and if it does not
exactly match the public key provided to this option, curl will abort the
connection before sending or receiving any data.
PEM/DER support:
7.39.0: OpenSSL, GnuTLS and GSKit
7.43.0: NSS and wolfSSL
7.47.0: mbedtls
sha256 support:
7.44.0: OpenSSL, GnuTLS, NSS and wolfSSL
7.47.0: mbedtls
Other SSL backends not supported.
If this option is used several times, the last one will be used.
Examples:
curl --pinnedpubkey keyfile https://example.com
curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --hostpubsha256. Added in 7.39.0.
--post301
(HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST requests 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.
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 requests 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.
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 requests 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.
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 will make 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 this option is used several times, the last one will be 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 transfers without a known size,
there will be 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.
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_PROTOCOL (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.
Example:
curl --proto-default https ftp.example.com
See also --proto and --proto-redir. Added in 7.45.0.
--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 will only allow HTTP, HTTPS, FTP and FTPS on redirect (since
7.65.2). Specifying all or +all enables all protocols on redirects, which is not
good for security.
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 protocol 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 protocols produce a warning. This allows scripts to safely rely on being
able to disable potentially dangerous protocols, 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.
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.
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.
Example:
curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-digest.
--proxy-cacert <file>
Same as --cacert but used in HTTPS proxy context.
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.
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.
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.
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.
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.
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.
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 equivalent 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 will make 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 will only mess things up for you.
Headers specified with this option will not be included in requests that curl knows
will not be sent to a proxy.
Starting in 7.55.0, this option can take an argument in @filename style, which then
adds a header for each line in the input file. Using @- will make curl read the
header file from stdin.
This option can be used multiple times to add/replace/remove multiple headers.
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. Added in 7.37.0.
--proxy-insecure
Same as -k, --insecure but used in HTTPS proxy context.
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.
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.
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 communicating with
the given proxy. Use --negotiate for enabling HTTP Negotiate (SPNEGO) with a remote
host.
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.
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.
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 certificate indicating
its identity. A public key is extracted from this certificate and if it does not
exactly match the public key provided to this option, curl will abort the
connection before sending or receiving any data.
If this option is used several times, the last one will be 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 negotiation.
Example:
curl --proxy-service-name "shrubbery" -x proxy https://example.com
See also --service-name and -x, --proxy. Added in 7.43.0.
--proxy-ssl-allow-beast
Same as --ssl-allow-beast but used in HTTPS proxy context.
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.
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 this option is used several times, the last one will be used.
Example:
curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com
See also --tls13-ciphers and --curves. Added in 7.61.0.
--proxy-tlsauthtype <type>
Same as --tlsauthtype but used in HTTPS proxy context.
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.
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.
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.
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 will hide the given option argument from process
listings. This is not enough to protect credentials from possibly getting seen by
other users on the same system as they will still be visible for a 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.
If this option is used several times, the last one will be 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 protocol specified
or http:// will be treated as HTTP proxy. Use socks4://, socks4a://, socks5:// or
socks5h:// to request a specific SOCKS version to be used.
HTTPS proxy support via https:// protocol prefix was added in 7.52.0 for OpenSSL,
GnuTLS and NSS.
Unrecognized and unsupported proxy protocols cause an error since 7.52.0. Prior
versions may ignore the protocol and use 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's an environment variable setting a proxy, you can set proxy to "" to
override it.
All operations that are performed over an HTTP proxy will transparently be
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.
If this option is used several times, the last one will be 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 will specify an HTTP 1.0 protocol instead
of the default HTTP 1.1.
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 will make curl tunnel 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.
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.
If this option is used several times, the last one will be used.
(As of 7.39.0, 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.)
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 '-'. To make commands be sent after
curl has changed the working directory, just before the transfer command(s), prefix
the command with a '+' (this is only supported for FTP). You may specify any number
of commands.
By default curl will stop 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 operation will be 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.
This option can be used multiple times.
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 target_file
location pointing to the source_file location.
mkdir directory_name
The mkdir command creates the directory named by the directory_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 pathname 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.
Example:
curl --quote "DELE file" ftp://example.com/foo
See also -X, --request.
--random-file <file>
Specify the path name to file containing what will be considered as random data.
The data may be used to seed the random engine for SSL connections. See also the
--egd-file option.
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 will cause the server to reply with a multipart response,
which will be returned as-is by curl! Parsing or otherwise transforming 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 will be unspecified, depending on the server's configuration.
You should also be aware that many HTTP/1.1 servers do not have this feature
enabled, so that when you attempt to get a range, you will instead get the whole
document.
FTP and SFTP range downloads only support the simple 'start-stop' syntax
(optionally with one of the numbers omitted). FTP use depends on the extended FTP
command SIZE.
If this option is used several times, the last one will be used.
Example:
curl --range 22-44 https://example.com
See also -C, --continue-at and -a, --append.
--raw (HTTP) When used, it disables all internal HTTP decoding of content or transfer
encodings and instead makes them passed on unaltered, 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 this option is used several times, the last one will be 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 specifies a file name and a file with that name already exists in the
current working directory it will not be overwritten and an error will occur. If
the server does not specify a file name then this option has no effect.
There's no attempt to decode %-sequences (yet) in the provided file name, so this
option may provide you with rather unexpected file names.
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.
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.
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 will be 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.
The remote file name to use for saving is extracted from the given URL, nothing
else, and if it already exists it will be overwritten. If you want the server to be
able to choose the file name refer to -J, --remote-header-name which can be used in
addition to this option. If the server chooses a file name and that name already
exists it will not be overwritten.
There is no URL decoding done on the file name. If it has %20 or other URL encoded
parts of the name, they will end up as-is as file name.
You may use this option as many times as the number of URLs you have.
Example:
curl -O https://example.com/filename
See also --remote-name-all.
-R, --remote-time
When used, this will make curl attempt to figure out the timestamp of the remote
file, and if that is available make the local file get that same timestamp.
Example:
curl --remote-time -o foo https://example.com
See also -O, --remote-name and -z, --time-cond.
--request-target <path>
(HTTP) Tells curl to use an alternative "target" (path) instead of using 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 *".
Example:
curl --request-target "*" -X OPTIONS https://example.com
See also -X, --request. Added in 7.55.0.
-X, --request <method>
(HTTP) Specifies a custom request method to use when communicating with the HTTP
server. The specified request method will be used instead of the method otherwise
used (which defaults to GET). Read the HTTP 1.1 specification for details and
explanations. Common additional HTTP requests 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 will not suffice. You need to use the -I, --head option.
The method string you set with -X, --request will be used for all requests, which
if you for example use -L, --location may cause unintended side-effects when curl
does not change request method according to the HTTP 30x response 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. (Added in 7.30.0)
(SMTP) Specifies a custom SMTP command to use instead of HELP or VRFY. (Added in
7.34.0)
If this option is used several times, the last one will be 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 will be 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 will be used first.
The provided address set by this option will be 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 will only make sense for long running
parallel transfers with a lot of files. In such cases, if this option is used curl
will try 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.
This option can be used many times to add many host names to resolve.
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
(eg in curlrc), there may be unintended consequences 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
option, since you may receive duplicate data.
By default curl will not error on an HTTP response code that indicates an HTTP
error, if the transfer was successful. 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 will retry 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.
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 transient error too
for --retry. This option is used together with --retry.
Example:
curl --retry-connrefused --retry 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 will make curl use the default backoff time.
If this option is used several times, the last one will be used.
Example:
curl --retry-delay 5 --retry https://example.com
See also --retry.
--retry-max-time <seconds>
The retry timer is reset before the first transfer attempt. Retries will be 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 will be 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 this option is used several times, the last one will be 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 will
retry 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 will first wait one second and then for
all forthcoming retries it will double the waiting time until it reaches 10 minutes
which then will be the delay between the rest of the retries. By using --retry-
delay you disable this exponential backoff algorithm. See also --retry-max-time to
limit the total time allowed for retries.
Since curl 7.66.0, curl will comply with the Retry-After: response header if one
was present to know when to issue the next retry.
If this option is used several times, the last one will be used.
Example:
curl --retry 7 https://example.com
See also --retry-max-time.
--sasl-authzid <identity>
Use this authorisation identity (authzid), during SASL PLAIN authentication, in
addition to the authentication identity (authcid) as specified by -u, --user.
If the option is not specified, the server will derive 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.
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.
Example:
curl --sasl-ir imap://example.com/
See also --sasl-authzid. Added in 7.31.0.
--service-name <name>
This option allows you to change the service name for SPNEGO.
Examples: --negotiate --service-name sockd would use sockd/server-name.
Example:
curl --service-name sockd/server https://example.com
See also --negotiate and --proxy-service-name. Added in 7.43.0.
-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.
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 will still output 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 meter but still
show error messages.
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.
This option overrides any previous use of -x, --proxy, as they are mutually
exclusive.
This option is superfluous since you can specify a socks4 proxy with -x, --proxy
using a socks4:// protocol prefix.
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy. In such a case curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy.
If this option is used several times, the last one will be 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.
This option overrides any previous use of -x, --proxy, as they are mutually
exclusive.
This option is superfluous since you can specify a socks4a proxy with -x, --proxy
using a socks4a:// protocol prefix.
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy. In such a case curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy.
If this option is used several times, the last one will be 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 default. Use
--socks5-gssapi to force GSS-API authentication to SOCKS5 proxies.
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 reference implementation
does not. The option --socks5-gssapi-nec allows the unprotected exchange of the
protection mode negotiation.
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.
Examples: --socks5 proxy-name --socks5-gssapi-service sockd would use sockd/proxy-
name --socks5 proxy-name --socks5-gssapi-service sockd/real-name would use
sockd/real-name for cases where the proxy-name does not match the principal name.
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 username/password authentication to SOCKS5
proxies.
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.
This option overrides any previous use of -x, --proxy, as they are mutually
exclusive.
This option is superfluous since you can specify a socks5 hostname proxy with -x,
--proxy using a socks5h:// protocol prefix.
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy. In such a case curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy.
If this option is used several times, the last one will be 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.
This option overrides any previous use of -x, --proxy, as they are mutually
exclusive.
This option is superfluous since you can specify a socks5 proxy with -x, --proxy
using a socks5:// protocol prefix.
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time -x,
--proxy is used with an HTTP/HTTPS proxy. In such a case curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy.
If this option is used several times, the last one will be used.
This option (as well as --socks4) does not work with IPV6, FTPS or LDAP.
Example:
curl --socks5 proxy.example:7000 https://example.com
See also --socks5-hostname and --socks4a.
-Y, --speed-limit <speed>
If a download 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 this option is used several times, the last one will be 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 download is slower than speed-limit bytes per second during a speed-time
period, the download gets aborted. If speed-time is used, the default speed-limit
will be 1 unless set with -Y, --speed-limit.
This option controls transfers and thus will not affect slow connects etc. If this
is a concern for you, try the --connect-timeout option.
If this option is used several times, the last one will be 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.
Example:
curl --ssl-allow-beast https://example.com
See also --proxy-ssl-allow-beast and -k, --insecure.
--ssl-auto-client-cert
Tell libcurl to automatically locate and use a client certificate for
authentication, when requested by the server. This option is only supported for
Schannel (the native Windows SSL library). Prior to 7.77.0 this was the default
behavior in libcurl with Schannel. Since the server can request any certificate
that supports client authentication in the OS certificate store it could be a
privacy violation and unexpected.
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.
Example:
curl --ssl-no-revoke https://example.com
See also --crlfile. Added in 7.44.0.
--ssl-reqd
(FTP IMAP POP3 SMTP LDAP) Require SSL/TLS for the connection. Terminates the
connection if the server does not support SSL/TLS.
This option is handled in LDAP since version 7.81.0. It is fully supported by the
openldap backend and rejected by the generic ldap backend if explicit TLS is
required.
This option was formerly known as --ftp-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.
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) Try to use SSL/TLS for the connection. Reverts to a non-
secure connection 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 since version 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
will be removed in a future version.
Example:
curl --ssl pop3://example.com/
See also -k, --insecure and --ciphers.
-2, --sslv2
(SSL) This option previously asked curl to use SSLv2, but starting in curl 7.77.0
this instruction is ignored. SSLv2 is widely considered insecure (see RFC 6176).
Example:
curl --sslv2 https://example.com
See also --http1.1 and --http2. -2, --sslv2 requires that the underlying libcurl
was built to support TLS. This option overrides -3, --sslv3 and -1, --tlsv1 and
--tlsv1.1 and --tlsv1.2.
-3, --sslv3
(SSL) This option previously asked curl to use SSLv3, but starting in curl 7.77.0
this instruction is ignored. SSLv3 is widely considered insecure (see RFC 7568).
Example:
curl --sslv3 https://example.com
See also --http1.1 and --http2. -3, --sslv3 requires that the underlying libcurl
was built to support TLS. This option overrides -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 this option is used several times, the last one will be 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.
This option is global and does not need to be specified for each use of -:, --next.
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.
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 (RFC7413).
Example:
curl --tcp-fastopen https://example.com
See also --false-start. Added in 7.49.0.
--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man page for details
about this option.
Since 7.50.2, curl sets this option by default and you need to explicitly switch it
off if you do not want it on.
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.
Example:
curl -t TTYPE=vt100 telnet://example.com/
See also -K, --config.
--tftp-blksize <value>
(TFTP) Set TFTP BLKSIZE option (must be >512). This is the block size that curl
will try to use when transferring data to or from a TFTP server. By default 512
bytes will be used.
If this option is used several times, the last one will be 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 acknowledge or
properly implement TFTP options. When this option is used --tftp-blksize is
ignored.
Example:
curl --tftp-no-options tftp://192.168.0.1/
See also --tftp-blksize. Added in 7.48.0.
-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 document that is
older than the given date/time, default is a document that is newer than the
specified date/time.
If this option is used several times, the last one will be 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>
(SSL) VERSION defines maximum supported TLS version. The minimum acceptable 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.
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 requires 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 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 --ciphers option.
If this option is used several times, the last one will be used.
Example:
curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com
See also --ciphers and --curves. 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 specified 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.
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.
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.
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.
Example:
curl --tlsv1.0 https://example.com
See also --tlsv1.3. Added in 7.34.0.
--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.
Example:
curl --tlsv1.1 https://example.com
See also --tlsv1.3. Added in 7.34.0.
--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.
Example:
curl --tlsv1.2 https://example.com
See also --tlsv1.3. Added in 7.34.0.
--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.
Example:
curl --tlsv1.3 https://example.com
See also --tlsv1.2. Added in 7.52.0.
-1, --tlsv1
(SSL) 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
Example:
curl --tlsv1 https://example.com
See also --http1.1 and --http2. -1, --tlsv1 requires that the underlying libcurl
was built to support TLS. This option overrides --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.
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 easier to read for
untrained humans.
This option is global and does not need to be specified for each use of -:, --next.
If this option is used several times, the last one will be used.
Example:
curl --trace-ascii log.txt https://example.com
See also -v, --verbose and --trace. This option overrides --trace and -v,
--verbose.
--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.
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 output sent to stderr.
This option is global and does not need to be specified for each use of -:, --next.
If this option is used several times, the last one will be used.
Example:
curl --trace log.txt https://example.com
See also --trace-ascii and --trace-time. This option overrides -v, --verbose and
--trace-ascii.
--unix-socket <path>
(HTTP) Connect through this Unix domain socket, instead of using the network.
Example:
curl --unix-socket socket-path https://example.com
See also --abstract-unix-socket. Added in 7.40.0.
-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 will append the local file name. NOTE that you must use
a trailing / on the last directory to really prove to Curl that there is no file
name or curl will think that your last directory name is the remote file name to
use. That will most likely cause the upload operation to fail. If this is used on
an HTTP(S) server, the PUT command will be used.
Use the file name "-" (a single dash) to use stdin instead of a given file.
Alternately, the file name "." (a single period) may be specified instead of "-" to
use stdin in non-blocking mode to allow reading server output while stdin is being
uploaded.
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 will not transcode nor encode it further in any way.
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 and -I, --head.
--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 will make a guess based on the host. If the outermost sub-domain name matches
DICT, FTP, IMAP, LDAP, POP3 or SMTP then that protocol will be used, otherwise HTTP
will be used. Since 7.45.0 guessing can be disabled by setting a default protocol,
see --proto-default for details.
This option may be used any number of times. 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!
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.
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 encode 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 will remove the header
completely from the request. If you prefer a blank header, you can set it to a
single space (" ").
If this option is used several times, the last one will be 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 will prompt 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 will hide the given option argument from process
listings. This is not enough to protect credentials from possibly getting seen by
other users on the same system as they will still be visible for a 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@example.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 select the user name and
password from your environment by specifying a single colon with this option: "-u
:".
If this option is used several times, the last one will be used.
Example:
curl -u user:secret https://example.com
See also -n, --netrc and -K, --config.
-v, --verbose
Makes curl verbose during the operation. Useful for debugging and seeing 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 additional info provided by curl.
If you only want HTTP headers in the output, -i, --include might be the option you
are looking for.
If you think this option still does not give you enough details, consider using
--trace or --trace-ascii instead.
This option is global and does not need to be specified for each use of -:, --next.
Use -s, --silent to make curl really quiet.
Example:
curl --verbose https://example.com
See also -i, --include. This option overrides --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 "Protocols:") shows all protocols that libcurl reports
to support.
The third 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 resolves can be
done using either the c-ares or the threaded resolver 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 error-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 will be 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 will be written to standard output, but this can be switched to standard
error by using %{stderr}.
NOTE: The %-symbol is a special symbol in the win32-environment, where all
occurrences of % must be doubled when using this option.
The variables available are:
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 exitcode 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.
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.
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 connection.
method The http method used in the most recent HTTP request. (Added in
7.72.0)
num_connects Number of new connects made in the recent transfer.
num_headers The number of response headers in the most recent request (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 returned 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 verification 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 will show 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 connection - can be
either IPv4 or IPv6.
remote_port The remote port number of the most recently done connection.
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 effectively
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, excluding 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 request.
size_upload The total amount of bytes that were uploaded. This is the size of
the body/data that was transferred, excluding 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 complete 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 will be written to
standard error. (Added in 7.63.0)
stdout From this point on, the -w, --write-out output will be written 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 redirections.
time_starttransfer
The time, in seconds, it took from the start until the first byte
was just about to be transferred. This includes time_pretransfer and
also the time the server needed to calculate the result.
time_total The total time, in seconds, that the full operation lasted.
url The URL that was fetched. (Added in 7.75.0)
urlnum The URL index number of this transfer, 0-indexed. De-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 this option is used several times, the last one will be used.
Example:
curl -w '%{http_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.
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 target URL
directly, and NO_PROXY=direct.example.com curl -x http://proxy.example.com
http://somewhere.example.com accesses the target 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.
IPv6 numerical addresses are compared as strings, so they will only match if the
representations are the same: "::1" is the same as "::0:1" but they do not match.
APPDATA <dir>
On Windows, this variable is used when trying to find the home directory. If the
primary home variable are all unset.
COLUMNS <terminal width>
If set, the specified number of characters will be used as the terminal width when
the alternative progress-bar is shown. If not set, curl will try to figure it out
using other ways.
CURL_CA_BUNDLE <file>
If set, will be 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 variable 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 alternative will make curl stay with the default.
SSL backend names (case-insensitive): bearssl, gnutls, gskit, mbedtls, mesalink,
nss, 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_CONFIG_HOME have preference.
QLOGDIR <directory name>
If curl was built with HTTP/3 support, setting this environment variable to a local
directory will make 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 both QUIC backends.
SHELL Used on VMS when trying to detect if using a DCL or a "unix" shell.
SSL_CERT_DIR <dir>
If set, will be used as the --capath value.
SSL_CERT_FILE <path>
If set, will be used as the --cacert value.
SSLKEYLOGFILE <file name>
If you set this environment variable to a file name, curl will store 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, libressl, BoringSSL, GnuTLS, NSS and
wolfSSL.
USERPROFILE <dir>
On Windows, this variable is used when trying to find the home directory. If the
other, primary, variable are all unset. If set, curl will use 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 alternative proxy
protocols.
If no protocol is specified in the proxy string or if the string does not match a
supported one, the proxy will be 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 messages that may
appear under error conditions. At the time of this writing, the exit codes are:
1 Unsupported protocol. This build of curl has no support for this protocol.
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 particular
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 error 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 similar.
25 FTP could not STOR file. The server denied the STOR operation, used for FTP
uploading.
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.
51 The peer's SSL certificate or SSH MD5 fingerprint was not OK.
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.
62 Invalid LDAP URL.
63 Maximum file size exceeded.
64 Requested FTP SSL level failed.
65 Sending the data requires a rewind that failed.
66 Failed to initialise 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).
75 Character conversion failed.
76 Character conversion functions required.
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 will be 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 details.
96 QUIC connection error. This error may be caused by an SSL library error. QUIC is
the protocol used for HTTP/3 transfers.
XX More error codes will 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)