### Meta-data
- Short: (single letter, without dash)
- Long: (long form name, without dashes)
+ Added: (version number in which this was added)
Arg: (the argument the option takes)
+ c: (copyright line)
+ Example: (example command line, without "curl" and can use `$URL`)
+ Experimental: yes (if so)
+ Help: (short text for the --help output for this option)
+ Long: (long form name, without dashes)
Magic: (description of "magic" options)
- Tags: (space separated list)
- Protocols: (space separated list for which protocols this option works)
- Added: (version number in which this was added)
+ Multi: single/append/boolean/mutex (if used more than once)
Mutexed: (space separated list of options this overrides, no dashes)
+ Protocols: (space separated list for which protocols this option works)
Requires: (space separated list of features this requires, no dashes)
See-also: (space separated list of related options, no dashes)
- Help: (short text for the --help output for this option)
- Example: (example command line, without "curl" and can use `$URL`)
- c: (copyright line)
+ Short: (single letter, without dash)
SPDX-License-Identifier: curl
+ Tags: (space separated list)
--- (end of meta-data)
### Body
Category: connection
See-also: unix-socket
Example: --abstract-unix-socket socketpath $URL
+Multi: single
---
Connect through an abstract Unix domain socket, instead of using the network.
Note: netstat shows the path of an abstract socket prefixed with '@', however
Category: http
See-also: resolve connect-to
Example: --alt-svc svc.txt $URL
+Multi: append
---
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,
Category: http proxy auth
Example: --anyauth --user me:pwd $URL
Added: 7.10.6
+Multi: mutex
---
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
See-also: range continue-at
Example: --upload-file local --append ftp://example.com/
Added: 4.8
+Multi: boolean
---
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
Added: 7.75.0
See-also: basic user
Example: --aws-sigv4 "aws:amz:east-2:es" --user "key:secret" $URL
+Multi: single
---
Use AWS V4 signature authentication in the transfer.
Category: auth
Example: -u name:password --basic $URL
Added: 7.10.6
+Multi: mutex
---
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
See-also: capath insecure
Example: --cacert CA-file.txt $URL
Added: 7.5
+Multi: single
---
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
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.
See-also: cacert insecure
Example: --capath /local/directory $URL
Added: 7.9.8
+Multi: single
---
Tells curl to use the specified certificate directory to verify the
peer. Multiple paths can be provided by separating them with ":" (e.g.
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.
+If this option is set, the default capath value will be ignored.
Category: tls
See-also: pinnedpubkey
Example: --cert-status $URL
+Multi: boolean
---
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.
+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.
Category: tls
Example: --cert-type PEM --cert file $URL
Added: 7.9.3
+Multi: single
---
Tells curl what type the provided client certificate is using. PEM, DER, ENG
and P12 are recognized types.
The default type depends on the TLS backend and is usually PEM, however for
Secure Transport and Schannel it is P12. If --cert is a pkcs11: URI then ENG is
the default type.
-
-If this option is used several times, the last one will be used.
Category: tls
Example: --cert certfile --key keyfile $URL
Added: 5.0
+Multi: single
---
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
store locations are supported: CurrentUser, LocalMachine, CurrentService,
Services, CurrentUserGroupPolicy, LocalMachineGroupPolicy,
LocalMachineEnterprise.
-
-If this option is used several times, the last one will be used.
See-also: tlsv1.3
Example: --ciphers ECDHE-ECDSA-AES256-CCM8 $URL
Added: 7.9
+Multi: single
---
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.
Category: scp ssh
See-also: compressed
Example: --compressed-ssh sftp://example.com/
+Multi: boolean
---
Enables built-in SSH compression.
This is a request, not an order; the server may or may not do it.
Example: --compressed $URL
See-also: compressed-ssh
Added: 7.10
+Multi: boolean
---
Request a compressed response using one of the algorithms curl supports, and
automatically decompress the content. Headers are not modified.
Example: --config file.txt $URL
Added: 4.10
See-also: disable
+Multi: append
---
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
On Windows two filenames are checked per location: .curlrc and _curlrc,
preferring the former. Older versions on Windows checked for _curlrc only.
-
-This option can be used multiple times to load multiple config files.
Example: --connect-timeout 20 $URL
Example: --connect-timeout 3.14 $URL
Added: 7.7
+Multi: single
---
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.
See-also: resolve header
Category: connection
Example: --connect-to example.com:443:example.net:8443 $URL
+Multi: append
---
For a request to the given HOST1:PORT1 pair, connect to HOST2:PORT2 instead.
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: -C - $URL
Example: -C 400 $URL
Added: 4.8
+Multi: single
---
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
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.
Example: -c store-here.txt -b read-these $URL
Added: 7.9
See-also: cookie
+Multi: single
---
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
will not fail or even report an error clearly. Using --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.
Example: -b cookiefile -c cookiefile $URL
See-also: cookie-jar junk-session-cookies
Added: 4.9
+Multi: append
---
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
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 --cookie and --cookie-jar in the same command
line is common.
Example: --create-dirs --output local/dir/file $URL
Added: 7.10.3
See-also: ftp-create-dirs output-dir
+Multi: boolean
---
When used in conjunction with the --output option, curl will create the
necessary local directory hierarchy as needed. This option creates the
See-also: ftp-create-dirs
Added: 7.75.0
Example: --create-file-mode 0777 -T localfile sftp://example.com/new
+Multi: single
---
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: --crlf -T file ftp://example.com/
Added: 5.7
See-also: use-ascii
+Multi: boolean
---
Convert LF to CRLF in upload. Useful for MVS (OS/390).
Category: tls
Example: --crlfile rejects.txt $URL
See-also: cacert capath
+Multi: single
---
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.
Category: tls
Example: --curves X25519 $URL
See-also: ciphers
+Multi: single
---
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
Example: --data-ascii @file $URL
Added: 7.2
See-also: data-binary data-raw data-urlencode
+Multi: append
---
This is just an alias for --data.
Example: --data-binary @filename $URL
Added: 7.2
See-also: data-ascii
+Multi: append
---
This posts data exactly as specified with no extra processing whatsoever.
Category: http post upload
Example: --data-raw "hello" $URL
Example: --data-raw "@at@at@" $URL
+Multi: append
---
This posts data similarly to --data but without the special
interpretation of the @ character.
Example: --data-urlencode =encodethis $URL
Example: --data-urlencode name@file $URL
Example: --data-urlencode @fileonly $URL
+Multi: append
---
This posts data, similar to the other --data options with the exception
that this performs URL-encoding.
Example: -d "name=curl" -d "tool=cmdline" $URL
Example: -d @filename $URL
Added: 4.0
+Multi: append
---
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
Example: --delegation "none" $URL
Added: 7.22.0
See-also: insecure ssl
+Multi: single
---
Set LEVEL to tell the server what it is allowed to delegate when it
comes to user credentials.
.IP "always"
Unconditionally allow the server to delegate.
.RE
-
-If this option is used several times, the last one will be used.
Category: proxy auth http
Example: -u name:password --digest $URL
Added: 7.10.6
+Multi: boolean
---
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 --user option to set user name and password.
-
-If this option is used several times, only the first one is used.
Example: --disable-eprt ftp://example.com/
Added: 7.10.5
See-also: disable-epsv ftp-port
+Multi: boolean
---
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
Example: --disable-epsv ftp://example.com/
Added: 7.9.2
See-also: disable-eprt ftp-port
+Multi: boolean
---
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
Example: -q $URL
Added: 5.0
See-also: config
+Multi: boolean
---
If used as the first parameter on the command line, the *curlrc* config
file will not be read and used. See the --config for details on the default
See-also: proto
Category: curl http
Example: --disallow-username-in-url $URL
+Multi: boolean
---
This tells curl to exit if passed a URL containing a username. This is probably
most useful when the URL is being provided at runtime or similar.
Requires: c-ares
Category: dns
Example: --dns-interface eth0 $URL
+Multi: single
---
Tell curl to send outgoing DNS requests through <interface>. This option is a
counterpart to --interface (which does not affect DNS). The supplied string
Requires: c-ares
Category: dns
Example: --dns-ipv4-addr 10.1.2.3 $URL
+Multi: single
---
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.
Requires: c-ares
Category: dns
Example: --dns-ipv6-addr 2a04:4e42::561 $URL
+Multi: single
---
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.
Category: dns
Example: --dns-servers 192.168.0.1,192.168.0.2 $URL
See-also: dns-interface dns-ipv4-addr
+Multi: single
---
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.
Category: dns tls
Example: --doh-cert-status --doh-url https://doh.example $URL
See-also: doh-insecure
+Multi: boolean
---
Same as --cert-status but used for DoH (DNS-over-HTTPS).
Category: dns tls
Example: --doh-insecure --doh-url https://doh.example $URL
See-also: doh-url
+Multi: boolean
---
Same as --insecure but used for DoH (DNS-over-HTTPS).
Category: dns
Example: --doh-url https://doh.example $URL
See-also: doh-insecure
+Multi: single
---
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.
This option is unset if an empty string "" is used as the URL. (Added in
7.85.0)
-
-If this option is used several times, the last one will be used.
Category: http ftp
Example: --dump-header store.txt $URL
Added: 5.7
+Multi: single
---
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.
Category: tls
Example: --egd-file /random/here $URL
Added: 7.7
+Multi: single
---
Deprecated option. This option is ignored by curl since 7.84.0. Prior to that
it only had an effect on curl if built to use old versions of OpenSSL.
Example: --engine flavor $URL
Added: 7.9.3
See-also: ciphers curves
+Multi: single
---
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
Category: http
Example: --etag-compare etag.txt $URL
See-also: etag-save time-cond
+Multi: single
---
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
Category: http
Example: --etag-save storetag.txt $URL
See-also: etag-compare
+Multi: single
---
This option saves an HTTP ETag to the specified file. An ETag is a
caching related header, usually returned in a response.
See-also: connect-timeout
Category: http
Example: --expect100-timeout 2.5 -T file $URL
+Multi: single
---
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
Category: curl
Example: --fail-early $URL https://two.example
See-also: fail fail-with-body
+Multi: boolean
---
Fail and exit on the first detected transfer error.
See-also: fail
Mutexed: fail
Example: --fail-with-body $URL
+Multi: boolean
---
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
Example: --fail $URL
Mutexed: fail-with-body
Added: 4.0
+Multi: boolean
---
Fail fast with no output at all on server errors. This is useful to enable
scripts and users to better deal with failed attempts. In normal cases when an
Category: tls
Example: --false-start $URL
See-also: tcp-fastopen
+Multi: boolean
---
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
Added: 7.81.0
Category: http upload
Example: --form-escape -F 'field\\name=curl' -F 'file=@load"this' $URL
+Multi: single
---
Tells curl to pass on names of multipart form fields and files using
backslash-escaping instead of percent-encoding.
Category: http upload
Example: --form-string "data" $URL
Added: 7.13.2
+Multi: append
---
Similar to --form except that the value string for the named parameter is used
literally. Leading '@' and '<' characters, and the ';type=' string in
Example: --form "name=curl" --form "file=@loadthis" $URL
Added: 5.0
See-also: data form-string form-escape
+Multi: append
---
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
-F '=@localfile;encoder=base64' ... smtp://example.com
See further examples and details in the MANUAL.
-
-This option can be used multiple times.
Category: ftp auth
Example: --ftp-account "mr.robot" ftp://example.com/
See-also: user
+Multi: single
---
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.
Category: ftp
Example: --ftp-alternative-to-user "U53r" ftp://example.com
See-also: ftp-account user
+Multi: single
---
If authenticating with the USER and PASS commands fails, send this command.
When connecting to Tumbleweed's Secure Transport server over FTPS using a
Category: ftp sftp curl
Example: --ftp-create-dirs -T file ftp://example.com/remote/path/file
Added: 7.10.7
+Multi: boolean
---
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
Example: --ftp-method nocwd ftp://example.com/dir1/dir2/file
Example: --ftp-method singlecwd ftp://example.com/dir1/dir2/file
See-also: list-only
+Multi: single
---
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:
See-also: disable-epsv
Category: ftp
Example: --ftp-pasv ftp://example.com/
+Multi: boolean
---
Use passive mode for the data connection. Passive is the internal default
behavior, but using this option can be used to override a previous --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 --ftp-port again.
+Reversing an enforced passive really is not doable but you must then instead
+enforce the correct --ftp-port again.
Passive mode means that curl will try the EPSV command first and then PASV,
unless --disable-epsv is used.
Example: -P eth0 ftp:/example.com
Example: -P 192.168.0.2 ftp:/example.com
Added: 4.0
+Multi: single
---
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
connection
.RE
-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++.
+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
Category: ftp
Example: --ftp-pret ftp://example.com/
See-also: ftp-port ftp-pasv
+Multi: boolean
---
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
See-also: ftp-pasv
Category: ftp
Example: --ftp-skip-pasv-ip ftp://example.com/
+Multi: boolean
---
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
See-also: ftp-ssl-ccc
Category: ftp tls
Example: --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/
+Multi: boolean
---
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
Added: 7.16.1
Category: ftp tls
Example: --ftp-ssl-ccc ftps://example.com/
+Multi: boolean
---
Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after
authenticating. The rest of the control channel communication will be
Category: ftp tls
Example: --ftp-ssl-control ftp://example.com
See-also: ssl
+Multi: boolean
---
Require SSL/TLS for the FTP login, clear for transfer. Allows secure
authentication, but non-encrypted data transfers for efficiency. Fails the
my @examples; # there can be more than one
my $magic; # cmdline special option
my $line;
+ my $multi;
+ my $experimental;
while(<F>) {
$line++;
if(/^Short: *(.)/i) {
elsif(/^Example: *(.*)/i) {
push @examples, $1;
}
+ elsif(/^Multi: *(.*)/i) {
+ $multi=$1;
+ }
+ elsif(/^Experimental: yes/i) {
+ $experimental=1;
+ }
elsif(/^C: (.*)/i) {
$copyright=$1;
}
print STDERR "ERROR: no 'Long:' in $f\n";
return 1;
}
+ if($multi !~ /(single|append|boolean|mutex)/) {
+ print STDERR "ERROR: bad 'Multi:' in $f\n";
+ return 1;
+ }
if(!$category) {
print STDERR "ERROR: no 'Category:' in $f\n";
return 2;
print ".SH DESCRIPTION\n";
}
+ if($experimental) {
+ print "**WARNING**: this option is experimental. Do not use in production.\n\n";
+ }
+
printdesc(@desc);
undef @desc;
+ if($multi eq "single") {
+ print "\nIf --$long is provided several times, the last set ".
+ "value will be used.\n";
+ }
+ elsif($multi eq "append") {
+ print "\n--$long can be used several times in a command line\n";
+ }
+ elsif($multi eq "boolean") {
+ my $rev = "no-$long";
+ # for options that start with "no-" the reverse is then without
+ # the no- prefix
+ if($long =~ /^no-/) {
+ $rev = $long;
+ $rev =~ s/^no-//;
+ }
+ print "\nProviding --$long multiple times has no extra effect.\n".
+ "Disable it again with --$rev.\n";
+ }
+ elsif($multi eq "mutex") {
+ print "\nProviding --$long multiple times has no extra effect.\n";
+ }
+
my @foot;
if($seealso) {
my @m=split(/ /, $seealso);
Example: --get -I -d "tool=curl" $URL
Added: 7.8.1
See-also: data request
+Multi: boolean
---
When used, this option will make all data specified with --data, --data-binary
or --data-urlencode to be used in an HTTP GET request instead of the POST
If used in combination with --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.
Example: -g "https://example.com/{[]}}}}"
Added: 7.6
See-also: config disable
+Multi: boolean
---
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
Category: connection
Example: --happy-eyeballs-timeout-ms 500 $URL
See-also: max-time connect-timeout
+Multi: single
---
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
"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.
Category: http proxy
Example: --haproxy-protocol $URL
See-also: proxy
+Multi: boolean
---
Send a HAProxy PROXY protocol v1 header at the beginning of the
connection. This is used by some load balancers and reverse proxies to
Example: -I $URL
Added: 4.0
See-also: get verbose trace-ascii
+Multi: boolean
---
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,
Example: -H "User-Agent: yes-please/2000" $URL
Example: -H "Host:" $URL
Added: 5.0
+Multi: append
---
Extra header to include in information sent. When used within an HTTP request,
it is added to the regular request headers.
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.
Example: --help all
Added: 4.0
See-also: verbose
+Multi: boolean
---
Usage help. This lists all commands of the <category>.
If no arg was provided, curl will display the most important
Category: sftp scp
Example: --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/
See-also: hostpubsha256
+Multi: single
---
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
Category: sftp scp
Example: --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/
See-also: hostpubmd5
+Multi: single
---
Pass a string containing a Base64-encoded SHA256 hash of the remote
host's public key. Curl will refuse the connection with the host
Category: http
Example: --hsts cache.txt $URL
See-also: proto
+Multi: append
---
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
Example: --http0.9 $URL
Added: 7.64.0
See-also: http1.1 http2 http3
+Multi: boolean
---
Tells curl to be fine with HTTP version 0.9 response.
Category: http
Example: --http1.0 $URL
See-also: http0.9 http1.1
+Multi: mutex
---
Tells curl to use HTTP version 1.0 instead of using its internally preferred
HTTP version.
Category: http
Example: --http1.1 $URL
See-also: http1.0 http0.9
+Multi: mutex
---
Tells curl to use HTTP version 1.1.
Category: http
Example: --http2-prior-knowledge $URL
See-also: http2 http3
+Multi: boolean
---
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
See-also: http1.1 http3
Category: http
Example: --http2 $URL
+Multi: mutex
---
Tells curl to use HTTP version 2.
See-also: http1.1 http2
Category: http
Example: --http3 $URL
+Multi: mutex
+Experimental: yes
---
-**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
Example: --ignore-content-length $URL
Added: 7.14.1
See-also: ftp-skip-pasv-ip
+Multi: boolean
---
For HTTP, Ignore the Content-Length header. This is particularly useful for
servers running Apache 1.x, which will report incorrect Content-Length for
Category: important verbose
Example: -i $URL
Added: 4.8
+Multi: boolean
---
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
Category: tls sftp scp
Example: --insecure $URL
Added: 7.10
+Multi: boolean
---
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
Category: connection
Example: --interface eth0 $URL
Added: 7.3
+Multi: single
---
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
Help: Resolve names to IPv4 addresses
Category: connection dns
Example: --ipv4 $URL
+Multi: boolean
---
This option tells curl to use IPv4 addresses only, and not for example try
IPv6.
Help: Resolve names to IPv6 addresses
Category: connection dns
Example: --ipv6 $URL
+Multi: boolean
---
This option tells curl to use IPv6 addresses only, and not for example try
IPv4.
Example: --json @prepared $URL
Example: --json @- $URL < json.txt
Added: 7.82.0
+Multi: append
---
Sends the specified JSON data in a POST request to the HTTP server. --json
works as a shortcut for passing on these three options:
Category: http
Example: --junk-session-cookies -b cookies.txt $URL
Added: 7.9.7
+Multi: boolean
---
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
Category: connection
Example: --keepalive-time 20 $URL
See-also: no-keepalive max-time
+Multi: single
---
This option sets the time a connection needs to remain idle before sending
keepalive probes and the time between individual keepalive probes. It is
connection down is OS dependent and is commonly 9 or 10. 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.
+If unspecified, the option defaults to 60 seconds.
Example: --key-type DER --key here $URL
Added: 7.9.3
See-also: key
+Multi: single
---
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: --cert certificate --key here $URL
Added: 7.9.3
See-also: key-type cert
+Multi: single
---
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:
ignored for TLS protocols (HTTPS, etc). Those backends expect the private key
to be already present in the keychain or PKCS#12 file containing the
certificate.
-
-If this option is used several times, the last one will be used.
Example: --krb clear ftp://example.com/
Added: 7.3
See-also: delegation ssl
+Multi: single
---
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.
Category: curl
Example: --libcurl client.c $URL
See-also: verbose
+Multi: single
---
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
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: --limit-rate 10M $URL
Added: 7.10
See-also: speed-limit speed-time
+Multi: single
---
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
If you also use the --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.
Category: ftp pop3
Example: --list-only ftp://example.com/dir/
See-also: quote request
+Multi: boolean
---
(FTP)
When listing an FTP directory, this switch forces a name-only view. This is
Category: connection
Example: --local-port 1000-3000 $URL
See-also: globoff
+Multi: single
---
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
Category: http auth
Example: --location-trusted -u user:password $URL
Added: 7.10.4
+Multi: boolean
---
Like --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
Example: -L $URL
Added: 4.9
See-also: resolve alt-svc
+Multi: boolean
---
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
Category: imap pop3 smtp auth
Example: --login-options 'AUTH=*' imap://example.com
See-also: user
+Multi: single
---
Specify the login options to use during server authentication.
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.
See-also: mail-rcpt mail-from
Category: smtp
Example: --mail-auth user@example.come -T mail smtp://example.com/
+Multi: single
---
Specify a single address. This will be used to specify the authentication
address (identity) of a submitted message that is being relayed to another
See-also: mail-rcpt mail-auth
Category: smtp
Example: --mail-from user@example.com -T mail smtp://example.com/
+Multi: single
---
Specify a single address that the given mail should get sent from.
Category: smtp
Example: --mail-rcpt-allowfails --mail-rcpt dest@example.com smtp://example.com
See-also: mail-rcpt
+Multi: boolean
---
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
Category: smtp
Example: --mail-rcpt user@example.net smtp://example.com
See-also: mail-rcpt-allowfails
+Multi: append
---
Specify a single email address, user name or mailing list name. Repeat this
option several times to send to multiple recipients.
Example: --manual
Added: 5.2
See-also: verbose libcurl trace
+Multi: boolean
---
Manual. Display the huge help text.
Category: connection
Example: --max-filesize 100K $URL
Added: 7.10.8
+Multi: single
---
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
Example: --max-redirs 3 --location $URL
Added: 7.5
See-also: location
+Multi: single
---
Set maximum number of redirections to follow. When --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: --max-time 10 $URL
Example: --max-time 2.92 $URL
Added: 4.0
+Multi: single
---
Maximum time in seconds that you allow each transfer to take. This is
useful for preventing your batch jobs from hanging for hours due to slow
If you enable retrying the transfer (--retry) then the maximum time counter is
reset each time the transfer is retried. You can use --retry-max-time to limit
the retry time.
-
-If this option is used several times, the last one will be used.
Category: misc
Example: --metalink file $URL
See-also: parallel
+Multi: single
---
This option was previously used to specify a metalink resource. Metalink
support has been disabled in curl since 7.78.0 for security reasons.
Category: auth http
Example: --negotiate -u : $URL
Added: 7.10.6
+Multi: mutex
---
Enables Negotiate (SPNEGO) authentication.
Category: curl
Example: --netrc-file netrc $URL
See-also: netrc user config
+Multi: single
---
This option is similar to --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.
+netrc file per invocation.
It will abide by --netrc-optional if specified.
Category: curl
Example: --netrc-optional $URL
Added: 7.9.8
+Multi: boolean
---
Similar to --netrc, but this option makes the .netrc usage **optional**
and not mandatory as the --netrc option does.
Example: --netrc $URL
Added: 4.6
See-also: netrc-file config user
+Multi: boolean
---
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
Example: $URL --next -d postthis www2.example.com
Example: -I $URL --next https://example.net/
See-also: parallel config
+Multi: append
---
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
Help: Disable the ALPN TLS extension
Category: tls http
Example: --no-alpn $URL
+Multi: boolean
---
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
Example: --no-buffer $URL
Added: 6.5
See-also: progress-bar
+Multi: boolean
---
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.
Added: 7.83.0
See-also: output remote-name
Example: --no-clobber --output local/dir/file $URL
+Multi: boolean
---
When used in conjunction with the --output, --remote-header-name,
--remote-name, or --remote-name-all options, curl avoids overwriting files
Example: --no-keepalive $URL
Added: 7.18.0
See-also: keepalive-time
+Multi: boolean
---
Disables the use of keepalive messages on the TCP connection. curl otherwise
enables them by default.
Help: Disable the NPN TLS extension
Category: tls http
Example: --no-npn $URL
+Multi: boolean
---
In curl 7.86.0 and later, curl never uses NPN.
Added: 7.67.0
Category: verbose
Example: --no-progress-meter -o store $URL
+Multi: boolean
---
Option to switch off the progress meter output without muting or otherwise
affecting warning and informational messages like --silent does.
Category: tls
Example: --no-sessionid $URL
See-also: insecure
+Multi: boolean
---
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
Category: proxy
Example: --noproxy "www.example" $URL
See-also: proxy
+Multi: single
---
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,
Category: auth http
Example: --ntlm-wb -u user:password $URL
Added: 7.22.0
+Multi: mutex
---
Enables NTLM much in the style --ntlm does, but hand over the authentication
to the separate binary ntlmauth application that is executed when needed.
Category: auth http
Example: --ntlm -u user:password $URL
Added: 7.10.6
+Multi: mutex
---
Enables NTLM authentication. The NTLM authentication method was designed by
Microsoft and is used by IIS web servers. It is a proprietary protocol,
Example: --oauth2-bearer "mF_9.B5f-4.1JqM" $URL
Added: 7.33.0
See-also: basic ntlm digest
+Multi: single
---
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 --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.
See-also: remote-name remote-header-name
Category: curl
Example: --output-dir "tmp" -O $URL
+Multi: single
---
-
This option specifies the directory in which files should be stored, when
--remote-name or --output are used.
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: "http://{site,host}.host[1-5].com" -o "#1_#2"
Example: -o file $URL -o file2 https://example.net
Added: 4.0
+Multi: append
---
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
See-also: parallel parallel-max
Category: connection curl
Example: --parallel-immediate -Z $URL -o file1 $URL -o file2
+Multi: boolean
---
When doing parallel transfers, this option will instruct curl that it should
rather prefer opening up more connections in parallel at once rather than
See-also: parallel
Category: connection curl
Example: --parallel-max 100 -Z $URL ftp://example.com/
+Multi: single
---
When asked to do parallel transfers, using --parallel, this option controls
the maximum amount of transfers to do simultaneously.
Category: connection curl
Example: --parallel $URL -o file1 $URL -o file2
See-also: next verbose
+Multi: boolean
---
Makes curl perform its transfers in parallel as compared to the regular serial
manner.
Example: --pass secret --key file $URL
Added: 7.9.3
See-also: key user
+Multi: single
---
Passphrase for the private key.
-
-If this option is used several times, the last one will be used.
Category: curl
Example: --path-as-is https://example.com/../../etc/passwd
See-also: request-target
+Multi: boolean
---
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
Example: --pinnedpubkey 'sha256//ce118b51897f4452dc' $URL
Added: 7.39.0
See-also: hostpubsha256
+Multi: single
---
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
7.47.0: mbedtls
Other SSL backends not supported.
-
-If this option is used several times, the last one will be used.
Added: 7.17.1
Category: http post
Example: --post301 --location -d "data" $URL
+Multi: boolean
---
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
Added: 7.19.1
Category: http post
Example: --post302 --location -d "data" $URL
+Multi: boolean
---
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
Added: 7.26.0
Category: http post
Example: --post303 --location -d "data" $URL
+Multi: boolean
---
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
Category: proxy
Example: --preproxy socks5://proxy.example -x http://http.example $URL
See-also: proxy socks5
+Multi: single
---
Use the specified SOCKS proxy before connecting to an HTTP or HTTPS --proxy. In
such a case curl first connects to the SOCKS proxy and then connects (through
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: -# -O $URL
Added: 5.10
See-also: styled-output
+Multi: boolean
---
Make curl display transfer progress as a simple progress bar instead of the
standard, more informational, meter.
Category: connection curl
Example: --proto-default https ftp.example.com
See-also: proto proto-redir
+Multi: single
---
Tells curl to use *protocol* for any URL missing a scheme name.
Category: connection curl
Example: --proto-redir =http,https $URL
See-also: proto
+Multi: single
---
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
Added: 7.20.2
Category: connection curl
Example: --proto =http,https,sftp $URL
+Multi: single
---
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
See-also: proxy proxy-basic proxy-digest
Category: proxy auth
Example: --proxy-anyauth --proxy-user user:passwd -x proxy $URL
+Multi: mutex
---
Tells curl to pick a suitable authentication method when communicating with
the given HTTP proxy. This might cause an extra request/response round-trip.
Category: proxy auth
Example: --proxy-basic --proxy-user user:passwd -x proxy $URL
Added: 7.12.0
+Multi: mutex
---
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
See-also: proxy-capath cacert capath proxy
Category: proxy tls
Example: --proxy-cacert CA-file.txt -x https://proxy $URL
+Multi: single
---
Same as --cacert but used in HTTPS proxy context.
See-also: proxy-cacert proxy capath
Category: proxy tls
Example: --proxy-capath /local/directory -x https://proxy $URL
+Multi: single
---
Same as --capath but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-cert-type PEM --proxy-cert file -x https://proxy $URL
See-also: proxy-cert
+Multi: single
---
Same as --cert-type but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-cert file -x https://proxy $URL
See-also: proxy-cert-type
+Multi: single
---
Same as --cert but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x https://proxy $URL
See-also: ciphers curves proxy
+Multi: single
---
Same as --ciphers but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-crlfile rejects.txt -x https://proxy $URL
See-also: crlfile proxy
+Multi: single
---
Same as --crlfile but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-digest --proxy-user user:passwd -x proxy $URL
Added: 7.12.0
+Multi: mutex
---
Tells curl to use HTTP Digest authentication when communicating with the given
proxy. Use --digest for enabling HTTP Digest with a remote host.
Example: --proxy-header "User-Agent: surprise" -x http://proxy $URL
Example: --proxy-header "Host:" -x http://proxy $URL
See-also: proxy
+Multi: append
---
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 --header
Category: proxy tls
Example: --proxy-insecure -x https://proxy $URL
See-also: proxy insecure
+Multi: boolean
---
Same as --insecure but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-key-type DER --proxy-key here -x https://proxy $URL
See-also: proxy-key proxy
+Multi: single
---
Same as --key-type but used in HTTPS proxy context.
Example: --proxy-key here -x https://proxy $URL
Added: 7.52.0
See-also: proxy-key-type proxy
+Multi: single
---
Same as --key but used in HTTPS proxy context.
See-also: proxy-anyauth proxy-basic
Category: proxy auth
Example: --proxy-negotiate --proxy-user user:passwd -x proxy $URL
+Multi: mutex
---
Tells curl to use HTTP Negotiate (SPNEGO) authentication when communicating
with the given proxy. Use --negotiate for enabling HTTP Negotiate (SPNEGO)
Category: proxy auth
Example: --proxy-ntlm --proxy-user user:passwd -x http://proxy $URL
Added: 7.10.7
+Multi: mutex
---
Tells curl to use HTTP NTLM authentication when communicating with the given
proxy. Use --ntlm for enabling NTLM with a remote host.
Category: proxy tls auth
Example: --proxy-pass secret --proxy-key here -x https://proxy $URL
See-also: proxy proxy-key
+Multi: single
---
Same as --pass but used in HTTPS proxy context.
Example: --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' $URL
Added: 7.59.0
See-also: pinnedpubkey proxy
+Multi: single
---
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
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.
Category: proxy tls
Example: --proxy-service-name "shrubbery" -x proxy $URL
See-also: service-name proxy
+Multi: single
---
This option allows you to change the service name for proxy negotiation.
Category: proxy tls
Example: --proxy-ssl-allow-beast -x https://proxy $URL
See-also: ssl-allow-beast proxy
+Multi: boolean
---
Same as --ssl-allow-beast but used in HTTPS proxy context.
Category: proxy tls
Example: --proxy-ssl-auto-client-cert -x https://proxy $URL
See-also: ssl-auto-client-cert proxy
+Multi: boolean
---
Same as --ssl-auto-client-cert but used in HTTPS proxy context.
Example: --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy $URL
Added: 7.61.0
See-also: tls13-ciphers curves
+Multi: single
---
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
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.
Category: proxy tls auth
Example: --proxy-tlsauthtype SRP -x https://proxy $URL
See-also: proxy proxy-tlsuser
+Multi: single
---
Same as --tlsauthtype but used in HTTPS proxy context.
Category: proxy tls auth
Example: --proxy-tlspassword passwd -x https://proxy $URL
See-also: proxy proxy-tlsuser
+Multi: single
---
Same as --tlspassword but used in HTTPS proxy context.
Category: proxy tls auth
Example: --proxy-tlsuser smith -x https://proxy $URL
See-also: proxy proxy-tlspassword
+Multi: single
---
Same as --tlsuser but used in HTTPS proxy context.
Category: proxy tls auth
Example: --proxy-tlsv1 -x https://proxy $URL
See-also: proxy
+Multi: mutex
---
Same as --tlsv1 but used in HTTPS proxy context.
Example: --proxy-user name:pwd -x proxy $URL
Added: 4.0
See-also: proxy-pass
+Multi: single
---
Specify the user name and password to use for proxy authentication.
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: --proxy http://proxy.example $URL
Added: 4.0
See-also: socks5 proxy-basic
+Multi: single
---
Use the specified proxy.
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: --proxy1.0 -x http://proxy $URL
Added: 7.19.4
See-also: proxy socks5 preproxy
+Multi: mutex
---
Use the specified HTTP 1.0 proxy. If the port number is not specified, it is
assumed at port 1080.
Category: proxy
Example: --proxytunnel -x http://proxy $URL
Added: 7.3
+Multi: boolean
---
When an HTTP proxy is used --proxy, this option will make curl tunnel through
the proxy. The tunnel approach is made with the HTTP proxy CONNECT request and
Example: --pubkey file.pub sftp://example.com/
Added: 7.16.2
See-also: pass
+Multi: single
---
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
Example: --quote "DELE file" ftp://example.com/foo
Added: 5.3
See-also: request
+Multi: append
---
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
Example: --random-file rubbish $URL
Added: 7.7
See-also: egd-file
+Multi: single
---
Deprecated option. This option is ignored by curl since 7.84.0. Prior to that
it only had an effect on curl if built to use old versions of OpenSSL.
Example: --range 22-44 $URL
Added: 4.0
See-also: continue-at append
+Multi: single
---
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.
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: --rate 14/m $URL
Added: 7.84.0
See-also: limit-rate retry-delay
+Multi: single
---
Specify the maximum transfer frequency you allow curl to use - in number of
transfer starts per time unit (sometimes called request rate). Without this
When retrying transfers, enabled with --retry, the separate retry delay logic
is used and not this setting.
-
-If this option is used several times, the last one will be used.
Category: http
Example: --raw $URL
See-also: tr-encoding
+Multi: boolean
---
When used, it disables all internal HTTP decoding of content or transfer
encodings and instead makes them passed on unaltered, raw.
Example: --referer "https://fake.example;auto" -L $URL
Example: --referer ";auto" -L $URL
Added: 4.0
+Multi: single
---
Sends the "Referrer Page" information to the HTTP server. This can also be set
with the --header flag of course. When used with --location you can append
";auto" to the --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 --referer.
-
-If this option is used several times, the last one will be used.
Example: -OJ https://example.com/file
Added: 7.20.0
See-also: remote-name
+Multi: boolean
---
This option tells the --remote-name option to use the server-specified
Content-Disposition filename instead of extracting a filename from the URL. If
Category: output
Example: --remote-name-all ftp://example.com/file1 ftp://example.com/file2
See-also: remote-name
+Multi: boolean
---
This option changes the default action for all given URLs to be dealt with as
if --remote-name were used for each one. So if you want to disable that for a
Example: -O https://example.com/filename
Added: 4.0
See-also: remote-name-all output-dir remote-header-name
+Multi: append
---
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.)
Example: --remote-time -o foo $URL
Added: 7.9
See-also: remote-name time-cond
+Multi: boolean
---
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
Category: curl
Example: --remove-on-error -o output $URL
Added: 7.83.0
+Multi: boolean
---
When curl returns an error when told to save output in a local file, this
option removes that saved file before exiting. This prevents curl from
Category: http
Example: --request-target "*" -X OPTIONS $URL
See-also: request
+Multi: single
---
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
Example: -X NLST ftp://example.com/
Added: 6.0
See-also: request-target
+Multi: single
---
(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
(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.
Category: connection dns
Example: --resolve example.com:443:127.0.0.1 $URL
See-also: connect-to alt-svc
+Multi: append
---
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
Category: curl
Example: --retry 5 --retry-all-errors $URL
See-also: retry
+Multi: boolean
---
Retry on any error. This option is used together with --retry.
Category: curl
Example: --retry-connrefused --retry $URL
See-also: retry retry-all-errors
+Multi: boolean
---
In addition to the other conditions, consider ECONNREFUSED as a transient
error too for --retry. This option is used together with --retry.
Category: curl
Example: --retry-delay 5 --retry $URL
See-also: retry
+Multi: single
---
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.
Category: curl
Example: --retry-max-time 30 --retry 10 $URL
See-also: retry
+Multi: single
---
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
made and while performing, it may take longer than this given time period. To
limit a single request's maximum time, use --max-time. Set this option to
zero to not timeout retries.
-
-If this option is used several times, the last one will be used.
Category: curl
Example: --retry 7 $URL
See-also: retry-max-time
+Multi: single
---
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
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.
Category: auth
Example: --sasl-authzid zid imap://example.com/
See-also: login-options
+Multi: single
---
Use this authorization identity (authzid), during SASL PLAIN authentication,
in addition to the authentication identity (authcid) as specified by --user.
Category: auth
Example: --sasl-ir imap://example.com/
See-also: sasl-authzid
+Multi: boolean
---
Enable initial response in SASL authentication.
Category: misc
Example: --service-name sockd/server $URL
See-also: negotiate proxy-service-name
+Multi: single
---
This option allows you to change the service name for SPNEGO.
Category: curl
Example: --show-error --silent $URL
Added: 5.9
+Multi: boolean
---
When used with --silent, it makes curl show an error message if it fails.
Category: important verbose
Example: -s $URL
Added: 4.0
+Multi: boolean
---
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
Category: proxy
Example: --socks4 hostname:4096 $URL
See-also: socks4a socks5 socks5-hostname
+Multi: single
---
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
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time
--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.
Category: proxy
Example: --socks4a hostname:4096 $URL
See-also: socks4 socks5 socks5-hostname
+Multi: single
---
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.
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time
--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.
Category: proxy auth
Example: --socks5-basic --socks5 hostname:4096 $URL
See-also: socks5
+Multi: mutex
---
Tells curl to use username/password authentication when connecting to a SOCKS5
proxy. The username/password authentication is enabled by default. Use
Category: proxy auth
Example: --socks5-gssapi-nec --socks5 hostname:4096 $URL
See-also: socks5
+Multi: boolean
---
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
Category: proxy auth
Example: --socks5-gssapi-service sockd --socks5 hostname:4096 $URL
See-also: socks5
+Multi: single
---
The default service name for a socks server is rcmd/server-fqdn. This option
allows you to change it.
Category: proxy auth
Example: --socks5-gssapi --socks5 hostname:4096 $URL
See-also: socks5
+Multi: boolean
---
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
Category: proxy
Example: --socks5-hostname proxy.example:7000 $URL
See-also: socks5 socks4a
+Multi: single
---
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.
Since 7.52.0, --preproxy can be used to specify a SOCKS proxy at the same time
--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.
Category: proxy
Example: --socks5 proxy.example:7000 $URL
See-also: socks5-hostname socks4a
+Multi: single
---
Use the specified SOCKS5 proxy - but resolve the host name locally. If the
port number is not specified, it is assumed at port 1080.
--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: --speed-limit 300 --speed-time 10 $URL
Added: 4.7
See-also: speed-time limit-rate max-time
+Multi: single
---
If a transfer is slower than this given speed (in bytes per second) for
speed-time seconds it gets aborted. speed-time is set with --speed-time and is
30 if not set.
-
-If this option is used several times, the last one will be used.
Example: --speed-limit 300 --speed-time 10 $URL
Added: 4.7
See-also: speed-limit limit-rate
+Multi: single
---
If a transfer runs slower than speed-limit bytes per second during a speed-time
period, the transfer is aborted. If speed-time is used, the default
This option controls transfers (in both directions) but 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.
Category: tls
Example: --ssl-allow-beast $URL
See-also: proxy-ssl-allow-beast insecure
+Multi: boolean
---
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
See-also: proxy-ssl-auto-client-cert
Category: tls
Example: --ssl-auto-client-cert $URL
+Multi: boolean
---
Tell libcurl to automatically locate and use a client certificate for
authentication, when requested by the server. This option is only supported
Category: tls
Example: --ssl-no-revoke $URL
See-also: crlfile
+Multi: boolean
---
(Schannel) This option tells curl to disable certificate revocation checks.
WARNING: this option loosens the SSL security, and by using this flag you ask
Category: tls
Example: --ssl-reqd ftp://example.com
See-also: ssl insecure
+Multi: boolean
---
Require SSL/TLS for the connection. Terminates the connection if the server
does not support SSL/TLS.
Category: tls
Example: --ssl-revoke-best-effort $URL
See-also: crlfile insecure
+Multi: boolean
---
(Schannel) This option tells curl to ignore certificate revocation checks when
they failed due to missing/offline distribution points for the revocation check
Category: tls
Example: --ssl pop3://example.com/
See-also: ssl-reqd insecure ciphers
+Multi: boolean
---
Warning: this is considered an insecure option. Consider using --ssl-reqd
instead to be sure curl upgrades to a secure connection.
Help: Use SSLv2
Category: tls
Example: --sslv2 $URL
+Multi: mutex
---
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
Help: Use SSLv3
Category: tls
Example: --sslv3 $URL
+Multi: mutex
---
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
Category: verbose
Example: --stderr output.txt $URL
Added: 6.2
+Multi: single
---
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.
Category: verbose
Example: --styled-output -I $URL
See-also: head verbose
+Multi: boolean
---
Enables the automatic use of bold font styles when writing HTTP headers to the
terminal. Use --no-styled-output to switch them off.
Category: proxy
Example: --suppress-connect-headers --include -x proxy $URL
Added: 7.54.0
+Multi: boolean
---
When --proxytunnel is used and a CONNECT request is made do not output proxy
CONNECT response headers. This option is meant to be used with --dump-header or
Category: connection
Example: --tcp-fastopen $URL
See-also: false-start
+Multi: boolean
---
Enable use of TCP Fast Open (RFC7413).
Category: connection
Example: --tcp-nodelay $URL
See-also: no-buffer
+Multi: boolean
---
Turn on the TCP_NODELAY option. See the *curl_easy_setopt(3)* man page for
details about this option.
Example: -t TTYPE=vt100 telnet://example.com/
Added: 7.7
See-also: config
+Multi: append
---
Pass options to the telnet protocol. Supported options are:
Category: tftp
Example: --tftp-blksize 1024 tftp://example.com/file
See-also: tftp-no-options
+Multi: single
---
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.
Category: tftp
Example: --tftp-no-options tftp://192.168.0.1/
See-also: tftp-blksize
+Multi: boolean
---
Tells curl not to send TFTP options requests.
Example: -z file $URL
Added: 5.8
See-also: etag-compare remote-time
+Multi: single
---
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
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.
Category: tls
Example: --tls-max 1.2 $URL
Example: --tls-max 1.3 --tlsv1.2 $URL
+Multi: single
---
VERSION defines maximum supported TLS version. The minimum acceptable version
is set by tlsv1.0, tlsv1.1, tlsv1.2 or tlsv1.3.
Example: --tls13-ciphers TLS_AES_128_GCM_SHA256 $URL
Added: 7.61.0
See-also: ciphers curves
+Multi: single
---
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
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.
Category: tls auth
Example: --tlsauthtype SRP $URL
See-also: tlsuser
+Multi: single
---
Set TLS authentication type. Currently, the only supported option is "SRP",
for TLS-SRP (RFC 5054). If --tlsuser and --tlspassword are specified but
Category: tls auth
Example: --tlspassword pwd --tlsuser user $URL
See-also: tlsuser
+Multi: single
---
Set password for use with the TLS authentication method specified with
--tlsauthtype. Requires that --tlsuser also be set.
Category: tls auth
Example: --tlspassword pwd --tlsuser user $URL
See-also: tlspassword
+Multi: single
---
Set username for use with the TLS authentication method specified with
--tlsauthtype. Requires that --tlspassword also is set.
Category: tls
Example: --tlsv1.0 $URL
See-also: tlsv1.3
+Multi: mutex
---
Forces curl to use TLS version 1.0 or later when connecting to a remote TLS server.
Category: tls
Example: --tlsv1.1 $URL
See-also: tlsv1.3 tls-max
+Multi: mutex
---
Forces curl to use TLS version 1.1 or later when connecting to a remote TLS server.
Category: tls
Example: --tlsv1.2 $URL
See-also: tlsv1.3 tls-max
+Multi: mutex
---
Forces curl to use TLS version 1.2 or later when connecting to a remote TLS server.
Category: tls
Example: --tlsv1.3 $URL
See-also: tlsv1.2 tls-max
+Multi: mutex
---
Forces curl to use TLS version 1.3 or later when connecting to a remote TLS
server.
Help: Use TLSv1.0 or greater
Category: tls
Example: --tlsv1 $URL
+Multi: mutex
---
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
Category: http
Example: --tr-encoding $URL
See-also: compressed
+Multi: boolean
---
Request a compressed Transfer-Encoding response using one of the algorithms
curl supports, and uncompress the data while receiving it.
Example: --trace-ascii log.txt $URL
Added: 7.9.7
See-also: verbose trace
+Multi: single
---
Enables a full trace dump of all incoming and outgoing data, including
descriptive information, to the given output file. Use "-" as filename to have
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.
Category: verbose
Example: --trace-time --trace-ascii output $URL
See-also: trace verbose
+Multi: boolean
---
Prepends a time stamp to each trace or verbose line that curl displays.
Example: --trace log.txt $URL
Added: 7.9.7
See-also: trace-ascii trace-time
+Multi: single
---
Enables a full trace dump of all incoming and outgoing data, including
descriptive information, to the given output file. Use "-" as filename to have
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.
Category: connection
See-also: abstract-unix-socket
Example: --unix-socket socket-path $URL
+Multi: single
---
Connect through this Unix domain socket, instead of using the network.
Example: --upload-file "{file1,file2}" $URL
Added: 4.0
See-also: get head
+Multi: append
---
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
Example: --url $URL
Added: 7.5
See-also: next config
+Multi: append
---
Specify a URL to fetch. This option is mostly handy when you want to specify
URL(s) in a config file.
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 --output or the --remote-name options.
+To control where this URL is written, use the --output or the --remote-name
+options.
**WARNING**: On Windows, particular file:// accesses can be converted to
network accesses by the operating system. Beware!
Example: -B ftp://example.com/README
Added: 5.0
See-also: crlf data-ascii
+Multi: boolean
---
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
Example: -A "Agent 007" $URL
Added: 4.5.1
See-also: header proxy-header
+Multi: single
---
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
If you give an empty argument to --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: -u user:secret $URL
Added: 4.0
See-also: netrc config
+Multi: single
---
Specify the user name and password to use for server authentication. Overrides
--netrc and --netrc-optional.
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.
Category: important verbose
Example: --verbose $URL
Added: 4.0
+Multi: boolean
---
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"
Example: --version
Added: 4.0
See-also: help manual
+Multi: boolean
---
Displays information about curl and the libcurl version it uses.
Example: -w '%{http_code}\\n' $URL
Added: 6.5
See-also: verbose head
+Multi: single
---
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
to follow location: headers.
.RE
.IP
-If this option is used several times, the last one will be used.
Example: --xattr -o storage $URL
Added: 7.21.3
See-also: remote-time write-out verbose
+Multi: boolean
---
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
projects / thirdparty / curl.git / commitdiff
