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curl(1) Curl Manual curl(1)
NAME
curl - transfer a URL
SYNOPSIS
curl [options] [URL...]
DESCRIPTION
curl is a tool to transfer data from or to a server, using one of the supported protocols
(DICT, FILE, FTP, FTPS, GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP,
RTSP, SCP, SFTP, SMTP, SMTPS, TELNET and 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, Metalink, 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'll find a detailed description in RFC 3986.
You can specify multiple URLs or parts of URLs by writing part sets within braces as in:
http://site.{one,two,three}.com
or you can get sequences of alphanumeric series by using [] as in:
ftp://ftp.numericals.com/file[1-100].txt
ftp://ftp.numericals.com/file[001-100].txt (with leading zeros)
ftp://ftp.letters.com/file[a-z].txt
Nested sequences are not supported, but you can use several ones next to each other:
http://any.org/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 sequen-
tial manner in the specified order.
You can specify a step counter for the ranges to get every Nth number or letter:
http://www.numericals.com/file[1-100:10].txt
http://www.letters.com/file[a-z:2].txt
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 instead very 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 invokes.
PROGRESS METER
curl normally displays a progress meter during operations, indicating the amount of trans-
ferred data, transfer speeds and estimated time left, etc.
curl displays this data to the terminal by default, so if you invoke curl to do an opera-
tion and it is about to write data to the terminal, it disables the progress meter as oth-
erwise 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 [file] or similar.
It is not the same case for 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, -# is your friend.
OPTIONS
In general, all boolean options are enabled with --option and yet again disabled with
--no-option. That is, you use the exact same option name but prefix it with "no-". How-
ever, in this list we mostly only list and show the --option version of them. (This con-
cept with --no options was added in 7.19.0. Previously most options were toggled on/off on
repeated use of the same command line option.)
-#, --progress-bar
Make curl display progress as a simple progress bar instead of the standard, more
informational, meter.
-0, --http1.0
(HTTP) Forces curl to issue its requests using HTTP 1.0 instead of using its inter-
nally preferred: HTTP 1.1.
-1, --tlsv1
(SSL) Forces curl to use TLS version 1.x when negotiating with a remote TLS server.
You can use options --tlsv1.0, --tlsv1.1, --tlsv1.2, and --tlsv1.3 to control the
TLS version more precisely (if the SSL backend in use supports such a level of con-
trol).
-2, --sslv2
(SSL) Forces curl to use SSL version 2 when negotiating with a remote SSL server.
-3, --sslv3
(SSL) Forces curl to use SSL version 3 when negotiating with a remote SSL server.
-4, --ipv4
If curl is capable of resolving an address to multiple IP versions (which it is if
it is IPv6-capable), this option tells curl to resolve names to IPv4 addresses
only.
-6, --ipv6
If curl is capable of resolving an address to multiple IP versions (which it is if
it is IPv6-capable), this option tells curl to resolve names to IPv6 addresses
only.
-a, --append
(FTP/SFTP) When used in an upload, this will tell curl to append to the target file
instead of overwriting it. If the file doesn't exist, it will be created. Note
that this flag is ignored by some SSH servers (including OpenSSH).
-A, --user-agent <agent string>
(HTTP) Specify the User-Agent string to send to the HTTP server. Some badly done
CGIs fail if this field isn't set to "Mozilla/4.0". To encode blanks in the string,
surround the string with single quote marks. This can also be set with the -H,
--header option of course.
If this option is used several times, the last one will be used.
--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.
Note that 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.
-b, --cookie <name=data>
(HTTP) Pass the data to the HTTP server as a cookie. It is supposedly the data pre-
viously 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 line, it is treated as a filename to use to read
previously stored cookie lines from, which should be used in this session if they
match. Using this method also activates the "cookie parser" which will make curl
record incoming cookies too, which may be handy if you're using this in combination
with the -L, --location option. The file format of the file to read cookies from
should be plain HTTP headers or the Netscape/Mozilla cookie file format.
NOTE that the file specified with -b, --cookie is only used as input. No cookies
will be stored in the file. To store cookies, use the -c, --cookie-jar option or
you could even save the HTTP headers to a file using -D, --dump-header!
If this option is used several times, the last one will be used.
-B, --use-ascii
(FTP/LDAP) Enable ASCII transfer. For FTP, this can also be enforced by using an
URL that ends with ";type=A". This option causes data sent to stdout to be in text
mode for win32 systems.
--basic
(HTTP) Tells curl to use HTTP Basic authentication. 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 --negoti-
ate).
-c, --cookie-jar <file name>
(HTTP) Specify to which file you want curl to write all cookies after a completed
operation. Curl writes all cookies previously read from a specified file as well as
all cookies received from remote server(s). If no cookies are known, no file 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 can't be created or written to, the whole curl operation won't
fail or even report an error clearly. Using -v 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.
-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.
--ciphers <list of ciphers>
(SSL) 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:
http://www.openssl.org/docs/apps/ciphers.html
NSS ciphers are done differently than OpenSSL and GnuTLS. The full list of NSS
ciphers is in the NSSCipherSuite entry at this URL: http://git.fedora-
hosted.org/cgit/mod_nss.git/plain/docs/mod_nss.html#Directives
If this option is used several times, the last one will be used.
--compressed
(HTTP) Request a compressed response using one of the algorithms curl supports, and
save the uncompressed document. If this option is used and the server sends an
unsupported encoding, curl will report an error.
--connect-timeout <seconds>
Maximum time in seconds that you allow the connection to the server to take. This
only limits the connection phase, once curl has connected this option is of no more
use. See also the -m, --max-time option.
If this option is used several times, the last one will be used.
--create-dirs
When used in conjunction with the -o option, curl will create the necessary local
directory hierarchy as needed. This option creates the dirs mentioned with the -o
option, nothing else. If the -o file name uses no dir or if the dirs it mentions
already exist, no dir will be created.
To create remote directories when using FTP or SFTP, try --ftp-create-dirs.
--crlf (FTP) Convert LF to CRLF in upload. Useful for MVS (OS/390).
--crlfile <file>
(HTTPS/FTPS) 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.
(Added in 7.19.7)
-d, --data <data>
(HTTP) 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 sub-
mit 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.
-d, --data is the same as --data-ascii. 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 together 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. The contents of the
file must already be URL-encoded. Multiple files can also be specified. Posting
data from a file named 'foobar' would thus be done with --data @foobar.
-D, --dump-header <file>
Write the protocol headers to the specified file.
This option is handy to use when you want to store the headers that an HTTP site
sends to you. Cookies from the headers could then be read in a second curl invoca-
tion by using the -b, --cookie option! The -c, --cookie-jar option is however a
better way to store cookies.
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.
--data-ascii <data>
See -d, --data.
--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 --data-ascii does, except that newlines are preserved
and conversions are never done.
If this option is used several times, the ones following the first will append data
as described in -d, --data.
--data-urlencode <data>
(HTTP) This posts data, similar to the other --data options with the exception that
this performs URL-encoding. (Added in 7.18.0)
To be CGI-compliant, the <data> part should begin with a name followed by a separa-
tor 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 doesn't 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.
--delegation LEVEL
Set LEVEL to tell the server what it is allowed to delegate when it comes to user
credentials. Used with GSS/kerberos.
none Don't allow any delegation.
policy Delegates if and only if the OK-AS-DELEGATE flag is set in the Kerberos ser-
vice ticket, which is a matter of realm policy.
always Unconditionally allow the server to delegate.
--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 com-
bination with the normal -u, --user option to set user name and password. See also
--ntlm, --negotiate and --anyauth for related options.
If this option is used several times, only the first one is used.
--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 an IPv6 host, 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.
--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.
-e, --referer <URL>
(HTTP) Sends the "Referer 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 --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 don't set an initial --referer.
If this option is used several times, the last one will be used.
-E, --cert <certificate[:password]>
(SSL) 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 PEM for-
mat. If the optional password isn't specified, it will be queried for on the ter-
minal. Note that this option assumes a "certificate" file that is the private key
and the private certificate concatenated! See --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 environ-
ment 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 con-
tains "\", it needs to be escaped as "\\" so that it is not recognized as an escape
character.
If this option is used several times, the last one will be used.
--engine <name>
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 (or none) of the
engines may be available at run-time.
--environment
(RISC OS ONLY) Sets a range of environment variables, using the names the -w option
supports, to allow easier extraction of useful information after having run curl.
--egd-file <file>
(SSL) Specify the path name to the Entropy Gathering Daemon socket. The socket is
used to seed the random engine for SSL connections. See also the --random-file
option.
--cert-type <type>
(SSL) Tells curl what certificate type the provided certificate is in. PEM, DER and
ENG are recognized types. If not specified, PEM is assumed.
If this option is used several times, the last one will be used.
--cacert <CA certificate>
(SSL) 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 vari-
able.
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 (lib-
nsspem.so) needs to be available for this option to work properly.
If this option is used several times, the last one will be used.
--capath <CA certificate directory>
(SSL) 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.
-f, --fail
(HTTP) Fail silently (no output at all) on server errors. This is mostly done to
better 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 out-
putting 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).
-F, --form <name=content>
(HTTP) This lets curl emulate a filled-in form in which a user has pressed the sub-
mit button. This causes curl to POST data using the Content-Type multipart/form-
data according to RFC 2388. 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 differ-
ence 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.
Example, to send your password file to the server, where 'password' is the name of
the form-field to which /etc/passwd will be the input:
curl -F password=@/etc/passwd www.mypasswords.com
To read content from stdin instead of a file, use - as the filename. This goes for
both @ and < constructs.
You can also tell curl what Content-Type to use by using 'type=', in a manner simi-
lar to:
curl -F "web=@index.html;type=text/html" url.com
or
curl -F "name=daniel;type=text/foo" url.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" url.com
If filename/path contains ',' or ';', it must be quoted by double-quotes like:
curl -F "file=@\"localfile\";filename=\"nameinpost\"" url.com
or
curl -F 'file=@"localfile";filename="nameinpost"' url.com
Note that if a filename/path is quoted by double-quotes, any double-quote or back-
slash within the filename must be escaped by backslash.
See further examples and details in the MANUAL.
This option can be used multiple times.
--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. (Added in 7.13.0)
If this option is used several times, the last one will be used.
--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. (Added in 7.15.5)
--ftp-create-dirs
(FTP/SFTP) When an FTP or SFTP URL/operation uses a path that doesn't currently
exist on the server, the standard behavior of curl is to fail. Using this option,
curl will instead attempt to create missing directories.
--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 very 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'.
(Added in 7.15.1)
--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. (Added in 7.11.0)
If this option is used several times, only the first one is used. Undoing an
enforced passive really isn't 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.
--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. (Added in
7.14.2)
This option has no effect if PORT, EPRT or EPSV is used instead of PASV.
--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. (Added in 7.20.x)
--ftp-ssl-ccc
(FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenti-
cating. The rest of the control channel communication will be unencrypted. This
allows NAT routers to follow the FTP transaction. The default mode is passive. See
--ftp-ssl-ccc-mode for other modes. (Added in 7.16.1)
--ftp-ssl-ccc-mode [active/passive]
(FTP) Use CCC (Clear Command Channel) 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. (Added in 7.16.2)
--ftp-ssl-control
(FTP) Require SSL/TLS for the FTP login, clear for transfer. Allows secure authen-
tication, but non-encrypted data transfers for efficiency. Fails the transfer if
the server doesn't support SSL/TLS. (Added in 7.16.0) that can still be used but
will be removed in a future version.
--form-string <name=string>
(HTTP) Similar to --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 --form if there's any pos-
sibility that the string value may accidentally trigger the '@' or '<' features of
--form.
-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 them being inter-
preted by curl itself. Note that these letters are not normal legal URL contents
but they should be encoded according to the URI standard.
-G, --get
When used, this option will make all data specified with -d, --data or --data-
binary 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, 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 doesn't make sense, but you should then instead enforce the alterna-
tive method you prefer.
-H, --header <header>
(HTTP) Extra header to use when getting a web page. 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're 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.
See also the -A, --user-agent and -e, --referer options.
This option can be used multiple times to add/replace/remove multiple headers.
--hostpubmd5 <md5>
(SCP/SFTP) 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 connec-
tion with the host unless the md5sums match. (Added in 7.17.1)
--ignore-content-length
(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.
-i, --include
(HTTP) Include the HTTP-header in the output. The HTTP-header includes things like
server-name, date of the document, HTTP-version and more...
-I, --head
(HTTP/FTP/FILE) Fetch the HTTP-header 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.
--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 http://www.netscape.com/
If this option is used several times, the last one will be used.
-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're closed down.
-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.
-k, --insecure
(SSL) This option explicitly allows curl to perform "insecure" SSL connections and
transfers. All SSL connections are attempted to be made secure by using the CA cer-
tificate bundle installed by default. This makes all connections considered "inse-
cure" fail unless -k, --insecure is used.
See this online resource for further details:
http://curl.haxx.se/docs/sslcerts.html
-K, --config <config file>
Specify which config file to read curl arguments from. The config file is a text
file in which command line arguments can be written which then will be used as if
they were written on the actual command line. Options and their parameters must be
specified on the same config file line, separated by whitespace, colon, the equals
sign or any combination thereof (however, the preferred separator is the equals
sign). If the parameter is to contain whitespace, 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 = "http://curl.haxx.se/docs/"
Long option names can optionally be given in the config file without the initial
double dashes.
When curl is invoked, it always (unless -q is used) checks for a default config
file and uses it if found. The default config file is checked for in the following
places in this order:
1) curl tries to find the "home dir": It first checks for the CURL_HOME and then
the HOME environment variables. Failing that, it uses getpwuid() on UNIX-like sys-
tems (which returns the home dir given the current user in your system). On Win-
dows, it then checks for the APPDATA variable, or as a last resort the '%USERPRO-
FILE%\Application Data'.
2) On windows, if there is no _curlrc file in the home dir, it checks for one in
the same dir the curl executable is placed. On UNIX-like systems, it will simply
try to load .curlrc from the determined home dir.
# --- Example file ---
# this is a comment
url = "curl.haxx.se"
output = "curlhere.html"
user-agent = "superagent/1.0"
# and fetch another URL too
url = "curl.haxx.se/docs/manpage.html"
-O
referer = "http://nowhereatall.com/"
# --- End of example file ---
This option can be used multiple times to load multiple config files.
--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. (Added in 7.18.0)
If this option is used several times, the last one will be used. If unspecified,
the option defaults to 60 seconds.
--key <key>
(SSL/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 this option is used several times, the last one will be used.
--key-type <type>
(SSL) 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.
--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.
This option requires a library built with kerberos4 or GSSAPI (GSS-Negotiate) sup-
port. This is not very common. Use -V, --version to see if your curl supports it.
If this option is used several times, the last one will be used.
-l, --list-only
(FTP) When listing an FTP directory, this switch forces a name-only view. Espe-
cially useful if you want to machine-parse the contents of an FTP directory since
the normal directory view doesn't use a standard look or format.
This option causes an FTP NLST command to be sent. Some FTP servers list only
files in their response to NLST; they do not include subdirectories and symbolic
links.
-L, --location
(HTTP/HTTPS) 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 won't 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 the request is not a plain GET (for example POST
or PUT), it will do 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.
--libcurl <file>
Append this option to any ordinary curl command line, and you will get a libcurl-
using C source code written to the file that does the equivalent of what your com-
mand-line operation does!
If this option is used several times, the last given file name will be used. (Added
in 7.16.1)
--limit-rate <speed>
Specify the maximum transfer rate you want curl to use. This feature is useful if
you have a limited pipe and you'd like your transfer not to use your entire band-
width.
The given speed is measured in bytes/second, unless a suffix is appended. Append-
ing '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.
The given rate is the average speed counted during the entire transfer. It means
that curl might use higher transfer speeds in short bursts, but over time it uses
no more than the given rate.
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.
--local-port <num>[-num]
Set a preferred number or range 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. (Added in 7.15.2)
--location-trusted
(HTTP/HTTPS) 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'll send your authentication
info (which is plaintext in the case of HTTP Basic authentication).
-m, --max-time <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. See also the --connect-timeout option.
If this option is used several times, the last one will be used.
--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.
(Added in 7.25.0)
--mail-from <address>
(SMTP) Specify a single address that the given mail should get sent from.
(Added in 7.20.0)
--max-filesize <bytes>
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.
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. This concerns both FTP and HTTP transfers.
--mail-rcpt <address>
(SMTP) Specify a single address that the given mail should get sent to. This option
can be used multiple times to specify many recipients.
(Added in 7.20.0)
--max-redirs <num>
Set maximum number of redirection-followings allowed. If -L, --location is used,
this option can be used to prevent curl from following redirections "in absurdum".
By default, the limit is set to 50 redirections. Set this option to -1 to make it
limitless.
If this option is used several times, the last one will be used.
--metalink
This option can tell curl to parse and process a given URI as Metalink file (both
version 3 and 4 (RFC 5854) are supported) and make use of the mirrors listed within
for failover if there are errors (such as the file or server not being available).
It will also verify the hash of the file after the download completes. The Metalink
file itself is downloaded and processed in memory and not stored in the local file
system.
Example to use a remote Metalink file:
curl --metalink http://www.example.com/example.metalink
To use a Metalink file in the local file system, use FILE protocol (file://):
curl --metalink file://example.metalink
Please note that if FILE protocol is disabled, there is no way to use a local Met-
alink file at the time of this writing. Also note that if --metalink and --include
are used together, --include will be ignored. This is because including headers in
the response will break Metalink parser and if the headers are included in the file
described in Metalink file, hash check will fail.
(Added in 7.27.0, if built against the libmetalink library.)
-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(4) or ftp(1) for details on
the file format. Curl will not complain if that file doesn't have the right permis-
sions (it should not be either world- or group-readable). The environment variable
"HOME" is used to find the home directory.
A quick and very 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' should
look similar to:
machine host.domain.com login myself password secret
-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.
--netrc-file
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, only the last
one will be used. (Added in 7.21.5)
This option overrides any use of --netrc as they are mutually exclusive. It will
also abide by --netrc-optional if specified.
--netrc-optional
Very similar to --netrc, but this option makes the .netrc usage optional and not
mandatory as the --netrc option does.
--negotiate
(HTTP) Enables GSS-Negotiate authentication. The GSS-Negotiate method was designed
by Microsoft and is used in their web applications. It is primarily meant as a sup-
port for Kerberos5 authentication but may be also used along with another authenti-
cation method. For more information see IETF draft draft-brezak-spnego-http-04.txt.
If you want to enable Negotiate for your proxy authentication, then use --proxy-
negotiate.
This option requires a library built with GSSAPI support. This is not very common.
Use -V, --version to see if your version supports GSS-Negotiate.
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 option aren't actually used.
If this option is used several times, only the first one is used.
--no-keepalive
Disables the use of keepalive messages on the TCP connection, as by default curl
enables them.
Note that this is the negated option name documented. You can thus use --keepalive
to enforce keepalive.
--no-sessionid
(SSL) 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. (Added in 7.16.0)
Note that this is the negated option name documented. You can thus use --sessionid
to enforce session-ID caching.
--noproxy <no-proxy-list>
Comma-separated list of hosts which do not 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 con-
tains 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. (Added in
7.19.4).
--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.
This option requires a library built with SSL support. Use -V, --version to see if
your curl supports NTLM.
If this option is used several times, only the first one is used.
-o, --output <file>
Write output to <file> instead of stdout. If you are using {} or [] to fetch multi-
ple documents, 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}.site.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.
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.
-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 remote file name to use for saving is extracted from the given URL, nothing
else.
Consequentially, the file will be saved in the current working directory. If you
want the file saved in a different directory, make sure you change current working
directory before you invoke curl with the -O, --remote-name flag!
You may use this option as many times as the number of URLs you have.
-p, --proxytunnel
When an HTTP proxy is used (-x, --proxy), this option will cause non-HTTP protocols
to attempt to tunnel through the proxy instead of merely using it to do HTTP-like
operations. 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.
-P, --ftp-port <address>
(FTP) Reverses the default initiator/listener roles when connecting with FTP. This
switch makes curl use active mode. In practice, curl then tells the server to con-
nect 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
i.e "eth0" to specify which interface's IP address you want to use (Unix
only)
IP address
i.e "192.168.10.1" to specify the exact IP address
host name
i.e "my.host.domain" to specify the machine
- make curl pick the same IP address that is already used for the control con-
nection
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++.
Starting in 7.19.5, you can 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.
--pass <phrase>
(SSL/SSH) Passphrase for the private key
If this option is used several times, the last one will be used.
--post301
(HTTP) Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GET
requests when following a 301 redirection. The non-RFC behaviour is ubiquitous in
web browsers, so curl does the conversion by default to maintain consistency. How-
ever, a server may require a POST to remain a POST after such a redirection. This
option is meaningful only when using -L, --location (Added in 7.17.1)
--post302
(HTTP) Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GET
requests when following a 302 redirection. The non-RFC behaviour is ubiquitous in
web browsers, so curl does the conversion by default to maintain consistency. How-
ever, a server may require a POST to remain a POST after such a redirection. This
option is meaningful only when using -L, --location (Added in 7.19.1)
--post303
(HTTP) Tells curl to respect RFC 2616/10.3.2 and not convert POST requests into GET
requests when following a 303 redirection. The non-RFC behaviour is ubiquitous in
web browsers, so curl does the conversion by default to maintain consistency. How-
ever, a server may require a POST to remain a POST after such a redirection. This
option is meaningful only when using -L, --location (Added in 7.26.0)
--proto <protocols>
Tells curl to use the listed protocols for its initial retrieval. 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.
(Added in 7.20.2)
--proto-redir <protocols>
Tells curl to use the listed protocols after a redirect. See --proto for how proto-
cols are represented.
(Added in 7.20.2)
--proxy-anyauth
Tells curl to pick a suitable authentication method when communicating with the
given proxy. This might cause an extra request/response round-trip. (Added in
7.13.2)
--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.
--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.
--proxy-negotiate
Tells curl to use HTTP Negotiate authentication when communicating with the given
proxy. Use --negotiate for enabling HTTP Negotiate with a remote host. (Added in
7.17.1)
--proxy-ntlm
Tells curl to use HTTP NTLM authentication when communicating with the given proxy.
Use --ntlm for enabling NTLM with a remote host.
--proxy1.0 <proxyhost[: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.
--pubkey <key>
(SSH) 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 pri-
vate 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.)
-q 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.
-Q, --quote <command>
(FTP/SFTP) Send an arbitrary command to the remote FTP or SFTP server. Quote com-
mands 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 com-
mand with a '+' (this is only supported for FTP). You may specify any number of
commands. If the server returns failure for one of the commands, the entire opera-
tion 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. When speaking to an FTP server, prefix the com-
mand with an asterisk (*) to make curl continue even if the command fails as by
default curl will stop at first failure.
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:
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 loca-
tion pointing to the source_file location.
mkdir directory_name
The mkdir command creates the directory named by the directory_name operand.
pwd The pwd command returns the absolute pathname of the current working direc-
tory.
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 op-
erand, provided it is empty.
symlink source_file target_file
See ln.
-r, --range <range>
(HTTP/FTP/SFTP/FILE) Retrieve a byte range (i.e a partial document) from a
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(*)(H)
500-700,600-799
specifies 300 bytes from offset 500(H)
100-199,500-599
specifies two separate 100-byte ranges(*)(H)
(*) = NOTE that this will cause the server to reply with a multipart response!
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'll 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.
-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.
--random-file <file>
(SSL) Specify the path name to file containing what will be considered as random
data. The data is used to seed the random engine for SSL connections. See also the
--egd-file option.
--raw (HTTP) When used, it disables all internal HTTP decoding of content or transfer
encodings and instead makes them passed on unaltered, raw. (Added in 7.16.2)
--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 spe-
cific URL after --remote-name-all has been used, you must use "-o -" or --no-
remote-name. (Added in 7.19.0)
--resolve <host:port:address>
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 nor-
mally 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.
This option can be used many times to add many host names to resolve.
(Added in 7.21.3)
--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 5xx 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. (Added in 7.12.3)
If this option is used several times, the last one will be used.
--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. (Added in 7.12.3)
If this option is used several times, the last one will be used.
--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 hasn't reached this given limit. Notice
that if the timer hasn't reached the limit, the request will be made and while per-
forming, 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. (Added in 7.12.3)
If this option is used several times, the last one will be used.
-s, --silent
Silent or quiet mode. Don't show progress meter or error messages. Makes Curl
mute.
-S, --show-error
When used with -s it makes curl show an error message if it fails.
--ssl (FTP, POP3, IMAP, SMTP) Try to use SSL/TLS for the connection. Reverts to a non-
secure connection if the server doesn't support SSL/TLS. See also --ftp-ssl-con-
trol and --ssl-reqd for different levels of encryption required. (Added in 7.20.0)
This option was formerly known as --ftp-ssl (Added in 7.11.0). That option name can
still be used but will be removed in a future version.
--ssl-reqd
(FTP, POP3, IMAP, SMTP) Require SSL/TLS for the connection. Terminates the connec-
tion if the server doesn't support SSL/TLS. (Added in 7.20.0)
This option was formerly known as --ftp-ssl-reqd (added in 7.15.5). That option
name can still be used but will be removed in a future version.
--ssl-allow-beast
(SSL) This option tells curl to not work around a security flaw in the SSL3 and
TLS1.0 protocols known as BEAST. If this option isn't used, the SSL layer may use
work-arounds known to cause interoperability problems with some older SSL implemen-
tations. WARNING: this option loosens the SSL security, and by using this flag you
ask for exactly that. (Added in 7.25.0)
--socks4 <host[:port]>
Use the specified SOCKS4 proxy. If the port number is not specified, it is assumed
at port 1080. (Added in 7.15.2)
This option overrides any previous use of -x, --proxy, as they are mutually exclu-
sive.
Since 7.21.7, this option is superfluous since you can specify a socks4 proxy with
-x, --proxy using a socks4:// protocol prefix.
If this option is used several times, the last one will be used.
--socks4a <host[:port]>
Use the specified SOCKS4a proxy. If the port number is not specified, it is assumed
at port 1080. (Added in 7.18.0)
This option overrides any previous use of -x, --proxy, as they are mutually exclu-
sive.
Since 7.21.7, this option is superfluous since you can specify a socks4a proxy with
-x, --proxy using a socks4a:// protocol prefix.
If this option is used several times, the last one will be used.
--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. (Added in
7.55.0)
--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 sup-
port). Use --socks5-basic to force username/password authentication to SOCKS5
proxies. (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. (Added in 7.18.0)
This option overrides any previous use of -x, --proxy, as they are mutually exclu-
sive.
Since 7.21.7, this option is superfluous since you can specify a socks5 hostname
proxy with -x, --proxy using a socks5h:// protocol prefix.
If this option is used several times, the last one will be used. (This option was
previously wrongly documented and used as --socks without the number appended.)
--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 exclu-
sive.
Since 7.21.7, this option is superfluous since you can specify a socks5 proxy with
-x, --proxy using a socks5:// protocol prefix.
If this option is used several times, the last one will be used. (This option was
previously wrongly documented and used as --socks without the number appended.)
This option (as well as --socks4) does not work with IPV6, FTPS or LDAP.
--socks5-gssapi-service <servicename>
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.
(Added in 7.19.4).
--socks5-gssapi-nec
As part of the gssapi 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 protec-
tion mode negotiation. (Added in 7.19.4).
--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.
If this option is used several times, the last one will be used.
-t, --telnet-option <OPT=val>
Pass options to the telnet protocol. Supported options are:
TTYPE=<term> Sets the terminal type.
XDISPLOC=<X display> Sets the X display location.
NEW_ENV=<var,val> Sets an environment variable.
-T, --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. Alter-
nately, 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 for each URL on the command line. Each -T + URL pair speci-
fies what to upload and to where. curl also supports "globbing" of the -T argument,
meaning that you can upload multiple files to a single URL by using the same URL
globbing style supported in the URL, like this:
curl -T "{file1,file2}" http://www.uploadtothissite.com
or even
curl -T "img[1-1000].png" ftp://ftp.picturemania.com/upload/
--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man page for details
about this option. (Added in 7.11.2)
--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.
(Added in 7.20.0)
--tlsauthtype <authtype>
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 underly-
ing libcurl is built with TLS-SRP support, which requires OpenSSL or GnuTLS with
TLS-SRP support. (Added in 7.21.4)
--tlspassword <password>
Set password for use with the TLS authentication method specified with
--tlsauthtype. Requires that --tlsuser also be set. (Added in 7.21.4)
--tlsuser <user>
Set username for use with the TLS authentication method specified with
--tlsauthtype. Requires that --tlspassword also be set. (Added in 7.21.4)
--tlsv1.0
(SSL) Forces curl to use TLS version 1.0 when negotiating with a remote TLS server.
(Added in 7.34.0)
--tlsv1.1
(SSL) Forces curl to use TLS version 1.1 when negotiating with a remote TLS server.
(Added in 7.34.0)
--tlsv1.2
(SSL) Forces curl to use TLS version 1.2 when negotiating with a remote TLS server.
(Added in 7.34.0)
--tlsv1.3
(SSL) Forces curl to use TLS version 1.3 when negotiating with a remote TLS server.
(Added in 7.52.0)
--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.
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.
See also --tlsv1.0 and --tlsv1.1 and --tlsv1.2 and --tlsv1.3. Added in 7.54.0.
--tr-encoding
(HTTP) Request a compressed Transfer-Encoding response using one of the algorithms
curl supports, and uncompress the data while receiving it.
(Added in 7.21.6)
--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.
This option overrides previous uses of -v, --verbose or --trace-ascii.
If this option is used several times, the last one will be used.
--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 very 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 overrides previous uses of -v, --verbose or --trace.
If this option is used several times, the last one will be used.
--trace-time
Prepends a time stamp to each trace or verbose line that curl displays. (Added in
7.14.0)
--unix-socket <path>
(HTTP) Connect through this UNIX domain socket, instead of using the network.
(Added in 7.40.0)
-u, --user <user:password>
Specify the user name and password to use for server authentication. Overrides -n,
--netrc and --netrc-optional.
If you just give the user name (without entering a colon) curl will prompt for a
password.
If you use an SSPI-enabled curl binary and do NTLM authentication, you can force
curl to pick up the user name and password from your environment by simply specify-
ing a single colon with this option: "-u :".
If this option is used several times, the last one will be used.
-U, --proxy-user <user:password>
Specify the user name and password to use for proxy authentication.
If you use an SSPI-enabled curl binary and do NTLM authentication, you can force
curl to pick up the user name and password from your environment by simply specify-
ing a single colon with this option: "-U :".
If this option is used several times, the last one will be used.
--url <URL>
Specify a URL to fetch. This option is mostly handy when you want to specify URL(s)
in a config file.
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.
-v, --verbose
Makes the fetching more verbose/talkative. Mostly useful for debugging. 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.
Note that if you only want HTTP headers in the output, -i, --include might be the
option you're looking for.
If you think this option still doesn't give you enough details, consider using
--trace or --trace-ascii instead.
This option overrides previous uses of --trace-ascii or --trace.
Use -s, --silent to make curl quiet.
-w, --write-out <format>
Defines what to display on stdout after a completed and successful operation. The
format is a string that may contain plain text mixed with any number of variables.
The string can be specified as "string", to get read from a particular file you
specify it "@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 %{vari-
able_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.
NOTE: The %-symbol is a special symbol in the win32-environment, where all occur-
rences 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.
filename_effective
The ultimate filename that curl writes out to. This is only meaning-
ful if curl is told to write to a file with the --remote-name or
--output option. It's most useful in combination with the --remote-
header-name option. (Added in 7.25.1)
ftp_entry_path The initial path curl ended up in when logging on to the remote FTP
server. (Added in 7.15.4)
http_code The numerical response code that was found in the last retrieved
HTTP(S) or FTP(s) transfer. In 7.18.2 the alias response_code was
added to show the same info.
http_connect The numerical code that was found in the last response (from a
proxy) to a curl CONNECT request. (Added in 7.12.4)
local_ip The IP address of the local end of the most recently done connection
- can be either IPv4 or IPv6 (Added in 7.29.0)
local_port The local port number of the most recently done connection (Added in
7.29.0)
num_connects Number of new connects made in the recent transfer. (Added in
7.12.3)
num_redirects Number of redirects that were followed in the request. (Added in
7.12.3)
redirect_url When an HTTP request was made without -L to follow redirects, this
variable will show the actual URL a redirect would take you to.
(Added in 7.18.2)
remote_ip The remote IP address of the most recently done connection - can be
either IPv4 or IPv6 (Added in 7.29.0)
remote_port The remote port number of the most recently done connection (Added
in 7.29.0)
size_download The total amount of bytes that were downloaded.
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.
speed_download The average download speed that curl measured for the complete down-
load. 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. (Added in
7.19.0)
time_appconnect
The time, in seconds, it took from the start until the SSL/SSH/etc
connect/handshake to the remote host was completed. (Added in
7.19.0)
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 resolv-
ing 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 include name
lookup, connect, pretransfer and transfer before the final transac-
tion was started. time_redirect shows the complete execution time
for multiple redirections. (Added in 7.12.3)
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. The time
will be displayed with millisecond resolution.
url_effective The URL that was fetched last. This is most meaningful if you've
told curl to follow location: headers.
If this option is used several times, the last one will be used.
-x, --proxy <[protocol://][user:password@]proxyhost[:port]>
Use the specified HTTP proxy. If the port number is not specified, it is assumed at
port 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 over-
ride it.
All operations that are performed over an HTTP proxy will transparently be con-
verted 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 exact same way as the proxy environment vari-
ables, including the protocol prefix (http://) and the embedded user + password.
From 7.21.7, the proxy string may 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, http:// and
all others will be treated as HTTP proxies.
If this option is used several times, the last one will be used.
-X, --request <command>
(HTTP) Specifies a custom request method to use when communicating with the HTTP
server. The specified request will be used instead of the method otherwise used
(which defaults to GET). Read the HTTP 1.1 specification for details and explana-
tions. Common additional HTTP requests include PUT and DELETE, but related tech-
nologies like WebDAV offers PROPFIND, COPY, MOVE and more.
Normally you don't 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.
(FTP) Specifies a custom FTP command to use instead of LIST when doing file lists
with FTP.
If this option is used several times, the last one will be used.
--xattr
When saving output to a file, this option tells curl to store certain file metadata
in extened 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.
-y, --speed-time <time>
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.
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.
-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 and is 30 if not set.
If this option is used several times, the last one will be used.
-z, --time-cond <date expression>|<file>
(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 doesn't 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 speci-
fied date/time.
If this option is used several times, the last one will be used.
-h, --help
Usage help.
-M, --manual
Manual. Display the huge help text.
-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:
IPv6 You can use IPv6 with this.
krb4 Krb4 for FTP is supported.
SSL HTTPS and FTPS are supported.
libz Automatic decompression of compressed files over HTTP is supported.
NTLM NTLM authentication is supported.
GSS-Negotiate
Negotiate authentication and krb5 for FTP is supported.
Debug This curl uses a libcurl built with Debug. This enables more error-tracking
and memory debugging etc. For curl-developers only!
AsynchDNS
This curl uses asynchronous name resolves.
SPNEGO SPNEGO Negotiate authentication is supported.
Largefile
This curl supports transfers of large files, files larger than 2GB.
IDN This curl supports IDN - international domain names.
SSPI SSPI is supported. If you use NTLM and set a blank user name, curl will
authenticate with your current user and password.
TLS-SRP
SRP (Secure Remote Password) authentication is supported for TLS.
Metalink
This curl supports Metalink (both version 3 and 4 (RFC 5854)), which
describes mirrors and hashes. curl will use mirrors for failover if there
are errors (such as the file or server not being available).
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 --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>
list of host names that shouldn't go through any proxy. If set to a asterisk '*'
only, it matches all hosts.
PROXY PROTOCOL PREFIXES
Since curl version 7.21.7, 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 doesn't match a supported
one, the proxy will be treated as an HTTP proxy.
The supported proxy protocol prefixes are as follows:
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 during bad 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 proba-
bly need another build of libcurl!
5 Couldn't resolve proxy. The given proxy host could not be resolved.
6 Couldn't resolve host. The given remote host was not resolved.
7 Failed to connect to host.
8 FTP weird server reply. The server sent data curl couldn't 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 doesn't exist on the server.
11 FTP weird PASS reply. Curl couldn't parse the reply sent to the PASS request.
13 FTP weird PASV reply, Curl couldn't parse the reply sent to the PASV request.
14 FTP weird 227 format. Curl couldn't parse the 227-line the server sent.
15 FTP can't get host. Couldn't resolve the host IP we got in the 227-line.
17 FTP couldn't set binary. Couldn't change transfer method to binary.
18 Partial file. Only a part of the file was transferred.
19 FTP couldn't 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 couldn't write data to a local filesystem or similar.
25 FTP couldn't STOR file. The server denied the STOR operation, used for FTP upload-
ing.
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 con-
ditions.
30 FTP PORT failed. The PORT command failed. Not all FTP servers support the PORT com-
mand, try doing a transfer using PASV instead!
31 FTP couldn't use REST. The REST command failed. This command is used for resumed
FTP transfers.
33 HTTP range error. The range "command" didn't work.
34 HTTP post error. Internal post-request generation error.
35 SSL connect error. The SSL handshaking failed.
36 FTP bad download resume. Couldn't continue an earlier aborted download.
37 FILE couldn't 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 didn't 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 Couldn't 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 with 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 (added in 7.19.0).
83 Issuer check failed (added in 7.19.0).
84 The FTP PRET command failed
85 RTSP: mismatch of CSeq numbers
86 RTSP: mismatch of Session Identifiers
87 unable to parse FTP file list
88 FTP chunk callback reported error
XX More error codes will appear here in future releases. The existing ones are meant
to never change.
AUTHORS / CONTRIBUTORS
Daniel Stenberg is the main author, but the whole list of contributors is found in the
separate THANKS file.
WWW
http://curl.haxx.se
FTP
ftp://ftp.sunet.se/pub/www/utilities/curl/
SEE ALSO
ftp(1), wget(1)
Curl 7.27.0 27 July 2012 curl(1)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache/2.4.6 (CentOS)
Under GNU General Public License
2024-11-23 17:43 @127.0.0.1 CrawledBy Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)