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Generated by the curl project gen.pl man page generator. .\" .TH curl 1 "16 Dec 2016" "Curl 7.52.0" "Curl Manual" .SH NAME curl \- transfer a URL .SH SYNOPSIS .B curl [options] .I [URL...] .SH DESCRIPTION .B 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, SMB, SMBS, 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 \fIlibcurl(3)\fP for details. .SH 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.example.com/file[1-100].txt ftp://ftp.example.com/file[001-100].txt (with leading zeros) ftp://ftp.example.com/file[a-z].txt Nested sequences are not supported, but you can use several ones next to each other: http://example.com/archive[1996-1999]/vol[1-4]/part{a,b,c}.html You can specify any amount of URLs on the command line. They will be fetched in a sequential manner in the specified order. You can specify a step counter for the ranges to get every Nth number or letter: http://example.com/file[1-100:10].txt http://example.com/file[a-z:2].txt When using [] or {} sequences when invoked from a command line prompt, you probably have to put the full URL within double quotes to avoid the shell from interfering with it. This also goes for other characters treated special, like for example '&', '?' and '*'. Provide the IPv6 zone index in the URL with an escaped percentage sign and the interface name. Like in http://[fe80::3%25eth0]/ If you specify URL without protocol:// prefix, curl will attempt to guess what protocol you might want. It will then default to HTTP but try other protocols based on often-used host name prefixes. For example, for host names starting with "ftp." curl will assume you want to speak FTP. curl will do its best to use what you pass to it as a URL. It is not trying to validate it as a syntactically correct URL by any means but is instead \fBvery\fP 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. .SH "PROGRESS METER" curl normally displays a progress meter during operations, indicating the amount of transferred data, transfer speeds and estimated time left, etc. The progress meter displays number of bytes and the speeds are in bytes per second. The suffixes (k, M, G, T, P) are 1024 based. For example 1k is 1024 bytes. 1M is 1048576 bytes. curl displays this data to the terminal by default, so if you invoke curl to do an operation and it is about to write data to the terminal, it \fIdisables\fP the progress meter as otherwise it would mess up the output mixing progress meter and response data. If you want a progress meter for HTTP POST or PUT requests, you need to redirect the response output to a file, using shell redirect (>), \fI-o, --output\fP 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, \fI-#, --progress-bar\fP is your friend. You can also disable the progress meter completely with the \fI-s, --silent\fP option. .SH OPTIONS Options start with one or two dashes. Many of the options require an additional value next to them. The short "single-dash" form of the options, -d for example, may be used with or without a space between it and its value, although a space is a recommended separator. The long "double-dash" form, \fI-d, --data\fP for example, requires a space between it and its value. Short version options that don't need any additional values can be used immediately next to each other, like for example you can specify all the options -O, -L and -v at once as -OLv. In general, all boolean options are enabled with --\fBoption\fP and yet again disabled with --\fBno-\fPoption. That is, you use the exact same option name but prefix it with "no-". However, in this list we mostly only list and show the --option version of them. (This concept 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.) .IP "--abstract-unix-socket " (HTTP) Connect through an abstract Unix domain socket, instead of using the network. Note: netstat shows the path of an abstract socket prefixed with '@', however the argument should not have this leading character. Added in 7.53.0. .IP "--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 \fI--basic\fP, \fI--digest\fP, \fI--ntlm\fP, and \fI--negotiate\fP. Using \fI--anyauth\fP is not recommended if you do uploads from stdin, since it may require data to be sent twice and then the client must be able to rewind. If the need should arise when uploading from stdin, the upload operation will fail. Used together with \fI-u, --user\fP. See also \fI--proxy-anyauth\fP and \fI--basic\fP and \fI--digest\fP. .IP "-a, --append" (FTP SFTP) When used in an upload, this makes curl append to the target file instead of overwriting it. If the remote file doesn't exist, it will be created. Note that this flag is ignored by some SFTP servers (including OpenSSH). .IP "--basic" (HTTP) Tells curl to use HTTP Basic authentication with the remote host. This is the default and this option is usually pointless, unless you use it to override a previously set option that sets a different authentication method (such as \fI--ntlm\fP, \fI--digest\fP, or \fI--negotiate\fP). Used together with \fI-u, --user\fP. See also \fI--proxy-basic\fP. .IP "--cacert " (TLS) Tells curl to use the specified certificate file to verify the peer. The file may contain multiple CA certificates. The certificate(s) must be in PEM format. Normally curl is built to use a default file for this, so this option is typically used to alter that default file. curl recognizes the environment variable named 'CURL_CA_BUNDLE' if it is set, and uses the given path as a path to a CA cert bundle. This option overrides that variable. The windows version of curl will automatically look for a CA certs file named \'curl-ca-bundle.crt\', either in the same directory as curl.exe, or in the Current Working Directory, or in any folder along your PATH. If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module (libnsspem.so) needs to be available for this option to work properly. (iOS and macOS only) If curl is built against Secure Transport, then this option is supported for backward compatibility with other SSL engines, but it should not be set. If the option is not set, then curl will use the certificates in the system and user Keychain to verify the peer, which is the preferred method of verifying the peer's certificate chain. If this option is used several times, the last one will be used. .IP "--capath " (TLS) Tells curl to use the specified certificate directory to verify the peer. Multiple paths can be provided by separating them with ":" (e.g. \&"path1:path2:path3"). The certificates must be in PEM format, and if curl is built against OpenSSL, the directory must have been processed using the c_rehash utility supplied with OpenSSL. Using \fI--capath\fP can allow OpenSSL-powered curl to make SSL-connections much more efficiently than using \fI--cacert\fP 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. .IP "--cert-status" (TLS) Tells curl to verify the status of the server certificate by using the Certificate Status Request (aka. OCSP stapling) TLS extension. If this option is enabled and the server sends an invalid (e.g. expired) response, if the response suggests that the server certificate has been revoked, or no response at all is received, the verification fails. This is currently only implemented in the OpenSSL, GnuTLS and NSS backends. Added in 7.41.0. .IP "--cert-type " (TLS) 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. See also \fI-E, --cert\fP and \fI--key\fP and \fI--key-type\fP. .IP "-E, --cert " (TLS) Tells curl to use the specified client certificate file when getting a file with HTTPS, FTPS or another SSL-based protocol. The certificate must be in PKCS#12 format if using Secure Transport, or PEM format if using any other engine. If the optional password isn't specified, it will be queried for on the terminal. Note that this option assumes a \&"certificate" file that is the private key and the client certificate concatenated! See \fI-E, --cert\fP and \fI--key\fP to specify them independently. If curl is built against the NSS SSL library then this option can tell curl the nickname of the certificate to use within the NSS database defined by the environment variable SSL_DIR (or by default /etc/pki/nssdb). If the NSS PEM PKCS#11 module (libnsspem.so) is available then PEM files may be loaded. If you want to use a file from the current directory, please precede it with "./" prefix, in order to avoid confusion with a nickname. If the nickname contains ":", it needs to be preceded by "\\" so that it is not recognized as password delimiter. If the nickname contains "\\", it needs to be escaped as "\\\\" so that it is not recognized as an escape character. (iOS and macOS only) If curl is built against Secure Transport, then the certificate string can either be the name of a certificate/private key in the system or user keychain, or the path to a PKCS#12-encoded certificate and private key. If you want to use a file from the current directory, please precede it with "./" prefix, in order to avoid confusion with a nickname. If this option is used several times, the last one will be used. See also \fI--cert-type\fP and \fI--key\fP and \fI--key-type\fP. .IP "--ciphers " (TLS) Specifies which ciphers to use in the connection. The list of ciphers must specify valid ciphers. Read up on SSL cipher list details on this URL: https://curl.haxx.se/docs/ssl-ciphers.html If this option is used several times, the last one will be used. .IP "--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. .IP "-K, --config " 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, or the equals sign. Long option names can optionally be given in the config file without the initial double dashes and if so, the colon or equals characters can be used as separators. If the option is specified with one or two dashes, there can be no colon or equals character between the option and its parameter. If the parameter 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 \fI-K, --config\fP 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 \fI--url\fP option, and not by simply writing the URL on its own line. So, it could look similar to this: url = "https://curl.haxx.se/docs/" When curl is invoked, it always (unless \fI-q, --disable\fP 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 systems (which returns the home dir given the current user in your system). On Windows, it then checks for the APPDATA variable, or as a last resort the '%USERPROFILE%\\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. .nf # --- Example file --- # this is a comment url = "example.com" output = "curlhere.html" user-agent = "superagent/1.0" # and fetch another URL too url = "example.com/docs/manpage.html" -O referer = "http://nowhereatall.example.com/" # --- End of example file --- .fi This option can be used multiple times to load multiple config files. .IP "--connect-timeout " 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 \fI-m, --max-time\fP. .IP "--connect-to " For a request to the given HOST:PORT pair, connect to CONNECT-TO-HOST:CONNECT-TO-PORT instead. This option is suitable to direct requests at a specific server, e.g. at a specific cluster node in a cluster of servers. This option is only used to establish the network connection. It does NOT affect the hostname/port that is used for TLS/SSL (e.g. SNI, certificate verification) or for the application protocols. "host" and "port" may be the empty string, meaning "any host/port". "connect-to-host" and "connect-to-port" may also be the empty string, meaning "use the request's original host/port". This option can be used many times to add many connect rules. See also \fI--resolve\fP and \fI-H, --header\fP. Added in 7.49.0. .IP "-C, --continue-at " 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. See also \fI-r, --range\fP. .IP "-c, --cookie-jar " (HTTP) Specify to which file you want curl to write all cookies after a completed operation. Curl writes all cookies from its in-memory cookie storage to the given file at the end of operations. If no cookies are known, no data will be written. The file will be written using the Netscape cookie file format. If you set the file name to a single dash, "-", the cookies will be written to stdout. This command line option will activate the cookie engine that makes curl record and use cookies. Another way to activate it is to use the \fI-b, --cookie\fP 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 \fI-v, --verbose\fP 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. .IP "-b, --cookie " (HTTP) Pass the data to the HTTP server in the Cookie header. It is supposedly the data previously received from the server in a "Set-Cookie:" line. The data should be in the format "NAME1=VALUE1; NAME2=VALUE2". If no '=' symbol is used in the argument, it is instead treated as a filename to read previously stored cookie from. This option also activates the cookie engine which will make curl record incoming cookies, which may be handy if you're using this in combination with the \fI-L, --location\fP option or do multiple URL transfers on the same invoke. The file format of the file to read cookies from should be plain HTTP headers (Set-Cookie style) or the Netscape/Mozilla cookie file format. The file specified with \fI-b, --cookie\fP is only used as input. No cookies will be written to the file. To store cookies, use the \fI-c, --cookie-jar\fP option. Exercise caution if you are using this option and multiple transfers may occur. If you use the NAME1=VALUE1; format, or in a file use the Set-Cookie format and don't specify a domain, then the cookie is sent for any domain (even after redirects are followed) and cannot be modified by a server-set cookie. If the cookie engine is enabled and a server sets a cookie of the same name then both will be sent on a future transfer to that server, likely not what you intended. To address these issues set a domain in Set-Cookie (doing that will include sub domains) or use the Netscape format. If this option is used several times, the last one will be used. Users very often want to both read cookies from a file and write updated cookies back to a file, so using both \fI-b, --cookie\fP and \fI-c, --cookie-jar\fP in the same command line is common. .IP "--create-dirs" When used in conjunction with the \fI-o, --output\fP option, curl will create the necessary local directory hierarchy as needed. This option creates the dirs mentioned with the \fI-o, --output\fP option, nothing else. If the --output 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 \fI--ftp-create-dirs\fP. .IP "--crlf" (FTP SMTP) Convert LF to CRLF in upload. Useful for MVS (OS/390). (SMTP added in 7.40.0) .IP "--crlfile " (TLS) Provide a file using PEM format with a Certificate Revocation List that may specify peer certificates that are to be considered revoked. If this option is used several times, the last one will be used. Added in 7.19.7. .IP "--data-ascii " (HTTP) This is just an alias for \fI-d, --data\fP. .IP "--data-binary " (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 \fI-d, --data\fP does, except that newlines and carriage returns 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 \fI-d, --data\fP. .IP "--data-raw " (HTTP) This posts data similarly to \fI-d, --data\fP but without the special interpretation of the @ character. See also \fI-d, --data\fP. Added in 7.43.0. .IP "--data-urlencode " (HTTP) This posts data, similar to the other \fI-d, --data\fP options with the exception that this performs URL-encoding. To be CGI-compliant, the part should begin with a \fIname\fP followed by a separator and a content specification. The part can be passed to curl using one of the following syntaxes: .RS .IP "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! .IP "=content" This will make curl URL-encode the content and pass that on. The preceding = symbol is not included in the data. .IP "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. .IP "@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. .IP "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 \fIname=urlencoded-file-content\fP. Note that the name is expected to be URL-encoded already. .RE See also \fI-d, --data\fP and \fI--data-raw\fP. Added in 7.18.0. .IP "-d, --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 submit button. This will cause curl to pass the data to the server using the content-type application/x-www-form-urlencoded. Compare to \fI-F, --form\fP. \fI--data-raw\fP is almost the same but does not have a special interpretation of the @ character. To post data purely binary, you should instead use the \fI--data-binary\fP option. To URL-encode the value of a form field you may use \fI--data-urlencode\fP. 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. Multiple files can also be specified. Posting data from a file named 'foobar' would thus be done with \fI-d, --data\fP @foobar. When --data is told to read from a file like that, carriage returns and newlines will be stripped out. If you don't want the @ character to have a special interpretation use \fI--data-raw\fP instead. See also \fI--data-binary\fP and \fI--data-urlencode\fP and \fI--data-raw\fP. This option overrides \fI-F, --form\fP and \fI-I, --head\fP and \fI--upload\fP. .IP "--delegation " (GSS/kerberos) Set LEVEL to tell the server what it is allowed to delegate when it comes to user credentials. .RS .IP "none" Don't allow any delegation. .IP "policy" Delegates if and only if the OK-AS-DELEGATE flag is set in the Kerberos service ticket, which is a matter of realm policy. .IP "always" Unconditionally allow the server to delegate. .RE .IP "--digest" (HTTP) Enables HTTP Digest authentication. This is an authentication scheme that prevents the password from being sent over the wire in clear text. Use this in combination with the normal \fI-u, --user\fP option to set user name and password. If this option is used several times, only the first one is used. See also \fI-u, --user\fP and \fI--proxy-digest\fP and \fI--anyauth\fP. This option overrides \fI--basic\fP and \fI--ntlm\fP and \fI--negotiate\fP. .IP "--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 \fI--disable-eprt\fP. If the server is accessed using IPv6, this option will have no effect as EPRT is necessary then. Disabling EPRT only changes the active behavior. If you want to switch to passive mode you need to not use \fI-P, --ftp-port\fP or force it with \fI--ftp-pasv\fP. .IP "--disable-epsv" (FTP) (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 \fI--disable-epsv\fP. 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 \fI-P, --ftp-port\fP. .IP "-q, --disable" If used as the first parameter on the command line, the \fIcurlrc\fP config file will not be read and used. See the \fI-K, --config\fP for details on the default config file search path. .IP "--dns-interface " (DNS) Tell curl to send outgoing DNS requests through . This option is a counterpart to \fI--interface\fP (which does not affect DNS). The supplied string must be an interface name (not an address). See also \fI--dns-ipv4-addr\fP and \fI--dns-ipv6-addr\fP. \fI--dns-interface\fP requires that the underlying libcurl was built to support c-ares. Added in 7.33.0. .IP "--dns-ipv4-addr
" (DNS) Tell curl to bind to when making IPv4 DNS requests, so that the DNS requests originate from this address. The argument should be a single IPv4 address. See also \fI--dns-interface\fP and \fI--dns-ipv6-addr\fP. \fI--dns-ipv4-addr\fP requires that the underlying libcurl was built to support c-ares. Added in 7.33.0. .IP "--dns-ipv6-addr
" (DNS) Tell curl to bind to when making IPv6 DNS requests, so that the DNS requests originate from this address. The argument should be a single IPv6 address. See also \fI--dns-interface\fP and \fI--dns-ipv4-addr\fP. \fI--dns-ipv6-addr\fP requires that the underlying libcurl was built to support c-ares. Added in 7.33.0. .IP "--dns-servers " 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 \fI:\fP after each IP address. \fI--dns-servers\fP requires that the underlying libcurl was built to support c-ares. Added in 7.33.0. .IP "-D, --dump-header " (HTTP FTP) Write the received 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 invocation by using the \fI-b, --cookie\fP option! The \fI-c, --cookie-jar\fP option is 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. See also \fI-o, --output\fP. .IP "--egd-file " (TLS) Specify the path name to the Entropy Gathering Daemon socket. The socket is used to seed the random engine for SSL connections. See also \fI--random-file\fP. .IP "--engine " (TLS) Select the OpenSSL crypto engine to use for cipher operations. Use \fI--engine\fP 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. .IP "--environment" Sets a range of environment variables, using the names the \fI-w, --write-out\fP option supports, to allow easier extraction of useful information after having run curl. \fI--environment\fP requires that the underlying libcurl was built to support RISC OS. .IP "--expect100-timeout " (HTTP) Maximum time in seconds that you allow curl to wait for a 100-continue response when curl emits an Expects: 100-continue header in its request. By default curl will wait one second. This option accepts decimal values! When curl stops waiting, it will continue as if the response has been received. See also \fI--connect-timeout\fP. Added in 7.47.0. .IP "--fail-early" Fail and exit on first detected error. When curl is used to do multiple transfers on the command line, it will attempt to operate on each given URL, one by one. By default, it will ignore errors if there are more URLs given and the last URL's success will determine the error code curl returns. So early failures will be "hidden" by subsequent successful transfers. Using this option, curl will instead return an error on the first transfers that fails, independent on the amount of more URLs that are given on the command line. This way, no transfer failures go undetected by scripts and similar. This option will apply for all given URLs even if you use \fI-:, --next\fP. Added in 7.52.0. .IP "-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 outputting that and return error 22. This method is not fail-safe and there are occasions where non-successful response codes will slip through, especially when authentication is involved (response codes 401 and 407). .IP "--false-start" (TLS) Tells curl to use false start during the TLS handshake. False start is a mode where a TLS client will start sending application data before verifying the server's Finished message, thus saving a round trip when performing a full handshake. This is currently only implemented in the NSS and Secure Transport (on iOS 7.0 or later, or OS X 10.9 or later) backends. Added in 7.42.0. .IP "--form-string " (HTTP) Similar to \fI-F, --form\fP 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 \fI-F, --form\fP if there's any possibility that the string value may accidentally trigger the \&'@' or \&'<' features of \fI-F, --form\fP. See also \fI-F, --form\fP. .IP "-F, --form " (HTTP) This lets curl emulate a filled-in form in which a user has pressed the submit button. This causes curl to POST data using the Content-Type multipart/form-data according to RFC 2388. This enables uploading of binary files etc. To force the 'content' part to be a file, prefix the file name with an @ sign. To just get the content part from a file, prefix the file name with the symbol <. The difference between @ and < is then that @ makes a file get attached in the post as a file upload, while the < makes a text field and just get the contents for that text field from a file. Example: to send an image to a server, where \&'profile' is the name of the form-field to which portrait.jpg will be the input: curl -F profile=@portrait.jpg https://example.com/upload.cgi To read content from stdin instead of a file, use - as the filename. This goes for both @ and < constructs. Unfortunately it does not support reading the file from a named pipe or similar, as it needs the full size before the transfer starts. You can also tell curl what Content-Type to use by using 'type=', in a manner similar to: curl -F "web=@index.html;type=text/html" example.com or curl -F "name=daniel;type=text/foo" example.com You can also explicitly change the name field of a file upload part by setting filename=, like this: curl -F "file=@localfile;filename=nameinpost" example.com If filename/path contains ',' or ';', it must be quoted by double-quotes like: curl -F "file=@\\"localfile\\";filename=\\"nameinpost\\"" example.com or curl -F 'file=@"localfile";filename="nameinpost"' example.com Note that if a filename/path is quoted by double-quotes, any double-quote or backslash within the filename must be escaped by backslash. See further examples and details in the MANUAL. This option can be used multiple times. This option overrides \fI-d, --data\fP and \fI-I, --head\fP and \fI--upload\fP. .IP "--ftp-account " (FTP) When an FTP server asks for "account data" after user name and password has been provided, this data is sent off using the ACCT command. If this option is used several times, the last one will be used. Added in 7.13.0. .IP "--ftp-alternative-to-user " (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. .IP "--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. See also \fI--create-dirs\fP. .IP "--ftp-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: .RS .IP 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. .IP 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. .IP 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'. .RE Added in 7.15.1. .IP "--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 \fI-P, --ftp-port\fP option. 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 \fI-P, --ftp-port\fP again. Passive mode means that curl will try the EPSV command first and then PASV, unless \fI--disable-epsv\fP is used. See also \fI--disable-epsv\fP. Added in 7.11.0. .IP "-P, --ftp-port
" (FTP) Reverses the default initiator/listener roles when connecting with FTP. This option makes curl use active mode. curl then tells the server to connect back to the client's specified address and port, while passive mode asks the server to setup an IP address and port for it to connect to.
should be one of: .RS .IP interface i.e "eth0" to specify which interface's IP address you want to use (Unix only) .IP "IP address" i.e "192.168.10.1" to specify the exact IP address .IP "host name" i.e "my.host.domain" to specify the machine .IP "-" make curl pick the same IP address that is already used for the control connection .RE If this option is used several times, the last one will be used. Disable the use of PORT with \fI--ftp-pasv\fP. Disable the attempt to use the EPRT command instead of PORT by using \fI--disable-eprt\fP. EPRT is really PORT++. Since 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. See also \fI--ftp-pasv\fP and \fI--disable-eprt\fP. .IP "--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 7.20.0. .IP "--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. This option has no effect if PORT, EPRT or EPSV is used instead of PASV. See also \fI--ftp-pasv\fP. Added in 7.14.2. .IP "--ftp-ssl-ccc-mode " (FTP) Sets the CCC mode. The passive mode will not initiate the shutdown, but instead wait for the server to do it, and will not reply to the shutdown from the server. The active mode initiates the shutdown and waits for a reply from the server. See also \fI--ftp-ssl-ccc\fP. Added in 7.16.2. .IP "--ftp-ssl-ccc" (FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenticating. The rest of the control channel communication will be unencrypted. This allows NAT routers to follow the FTP transaction. The default mode is passive. See also \fI--ssl\fP and \fI--ftp-ssl-ccc-mode\fP. Added in 7.16.1. .IP "--ftp-ssl-control" (FTP) Require SSL/TLS for the FTP login, clear for transfer. Allows secure authentication, but non-encrypted data transfers for efficiency. Fails the transfer if the server doesn't support SSL/TLS. Added in 7.16.0. .IP "-G, --get" When used, this option will make all data specified with \fI-d, --data\fP, \fI--data-binary\fP or \fI--data-urlencode\fP 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 \fI-I, --head\fP, 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 alternative method you prefer. .IP "-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 interpreted by curl itself. Note that these letters are not normal legal URL contents but they should be encoded according to the URI standard. .IP "-I, --head" (HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the command HEAD which this uses to get nothing but the header of a document. When used on an FTP or FILE file, curl displays the file size and last modification time only. .IP "-H, --header
" (HTTP) Extra header to include in the request when sending HTTP to a server. You may specify any number of extra headers. Note that if you should add a custom header that has the same name as one of the internal ones curl would use, your externally set header will be used instead of the internal one. This allows you to make even trickier stuff than curl would normally do. You should not replace internally set headers without knowing perfectly well what you'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 \fBnot\fP 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 \fI-A, --user-agent\fP and \fI-e, --referer\fP options. Starting in 7.37.0, you need \fI--proxy-header\fP to send custom headers intended for a proxy. Example: curl -H "X-First-Name: Joe" http://example.com/ \fBWARNING\fP: headers set with this option will be set in all requests - even after redirects are followed, like when told with \fI-L, --location\fP. This can lead to the header being sent to other hosts than the original host, so sensitive headers should be used with caution combined with following redirects. This option can be used multiple times to add/replace/remove multiple headers. .IP "-h, --help" Usage help. This lists all current command line options with a short description. .IP "--hostpubmd5 " (SFTP SCP) Pass a string containing 32 hexadecimal digits. The string should be the 128 bit MD5 checksum of the remote host's public key, curl will refuse the connection with the host unless the md5sums match. Added in 7.17.1. .IP "-0, --http1.0" (HTTP) Tells curl to use HTTP version 1.0 instead of using its internally preferred HTTP version. This option overrides \fI--http1.1\fP and \fI--http2\fP. .IP "--http1.1" (HTTP) Tells curl to use HTTP version 1.1. This option overrides \fI-0, --http1.0\fP and \fI--http2\fP. Added in 7.33.0. .IP "--http2-prior-knowledge" (HTTP) Tells curl to issue its non-TLS HTTP requests using HTTP/2 without HTTP/1.1 Upgrade. It requires prior knowledge that the server supports HTTP/2 straight away. HTTPS requests will still do HTTP/2 the standard way with negotiated protocol version in the TLS handshake. \fI--http2-prior-knowledge\fP requires that the underlying libcurl was built to support HTTP/2. This option overrides \fI--http1.1\fP and \fI-0, --http1.0\fP and \fI--http2\fP. Added in 7.49.0. .IP "--http2" (HTTP) Tells curl to use HTTP version 2. See also \fI--no-alpn\fP. \fI--http2\fP requires that the underlying libcurl was built to support HTTP/2. This option overrides \fI--http1.1\fP and \fI-0, --http1.0\fP and \fI--http2-prior-knowledge\fP. Added in 7.33.0. .IP "--ignore-content-length" (FTP HTTP) For HTTP, Ignore the Content-Length header. This is particularly useful for servers running Apache 1.x, which will report incorrect Content-Length for files larger than 2 gigabytes. For FTP (since 7.46.0), skip the RETR command to figure out the size before downloading a file. .IP "-i, --include" Include the HTTP-header in the output. The HTTP-header includes things like server-name, date of the document, HTTP-version and more... See also \fI-v, --verbose\fP. .IP "-k, --insecure" (TLS) 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 certificate bundle installed by default. This makes all connections considered \&"insecure" fail unless \fI-k, --insecure\fP is used. See this online resource for further details: https://curl.haxx.se/docs/sslcerts.html .IP "--interface " 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. See also \fI--dns-interface\fP. .IP "-4, --ipv4" This option tells curl to resolve names to IPv4 addresses only, and not for example try IPv6. See also \fI--http1.1\fP and \fI--http2\fP. This option overrides \fI-6, --ipv6\fP. .IP "-6, --ipv6" This option tells curl to resolve names to IPv6 addresses only, and not for example try IPv4. See also \fI--http1.1\fP and \fI--http2\fP. This option overrides \fI-6, --ipv6\fP. .IP "-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. See also \fI-b, --cookie\fP and \fI-c, --cookie-jar\fP. .IP "--keepalive-time " 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 \fI--no-keepalive\fP is used. If this option is used several times, the last one will be used. If unspecified, the option defaults to 60 seconds. Added in 7.18.0. .IP "--key-type " (TLS) Private key file type. Specify which type your \fI--key\fP 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. .IP "--key " (TLS SSH) Private key file name. Allows you to provide your private key in this separate file. For SSH, if not specified, curl tries the following candidates in order: '~/.ssh/id_rsa', '~/.ssh/id_dsa', './id_rsa', './id_dsa'. If this option is used several times, the last one will be used. .IP "--krb " (FTP) Enable Kerberos authentication and use. The level must be entered and should be one of 'clear', 'safe', 'confidential', or 'private'. Should you use a level that is not one of these, 'private' will instead be used. If this option is used several times, the last one will be used. \fI--krb\fP requires that the underlying libcurl was built to support Kerberos. .IP "--libcurl " 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 command-line operation does! If this option is used several times, the last given file name will be used. Added in 7.16.1. .IP "--limit-rate " 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'd like your transfer not to use your entire bandwidth. To make it slower than it otherwise would be. The given speed is measured in bytes/second, unless a suffix is appended. Appending 'k' or 'K' will count the number as kilobytes, 'm' or M' makes it megabytes, while 'g' or 'G' makes it gigabytes. Examples: 200K, 3m and 1G. If you also use the \fI-Y, --speed-limit\fP 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. .IP "-l, --list-only" (FTP POP3) (FTP) When listing an FTP directory, this switch forces a name-only view. This is especially useful if the user wants to machine-parse the contents of an FTP directory since the normal directory view doesn't use a standard look or format. When used like this, the option causes a NLST command to be sent to the server instead of LIST. Note: Some FTP servers list only files in their response to NLST; they do not include sub-directories and symbolic links. (POP3) When retrieving a specific email from POP3, this switch forces a LIST command to be performed instead of RETR. This is particularly useful if the user wants to see if a specific message id exists on the server and what size it is. Note: When combined with \fI-X, --request\fP, this option can be used to send an UIDL command instead, so the user may use the email's unique identifier rather than it's message id to make the request. Added in 7.21.5. .IP "--local-port " Set a preferred single number or range (FROM-TO) of local port numbers to use for the connection(s). Note that port numbers by nature are a scarce resource that will be busy at times so setting this range to something too narrow might cause unnecessary connection setup failures. Added in 7.15.2. .IP "--location-trusted" (HTTP) Like \fI-L, --location\fP, 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). See also \fI-u, --user\fP. .IP "-L, --location" (HTTP) If the server reports that the requested page has moved to a different location (indicated with a Location: header and a 3XX response code), this option will make curl redo the request on the new place. If used together with \fI-i, --include\fP or \fI-I, --head\fP, 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 \fI--location-trusted\fP on how to change this. You can limit the amount of redirects to follow by using the \fI--max-redirs\fP 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. You can tell curl to not change the non-GET request method to GET after a 30x response by using the dedicated options for that: \fI--post301\fP, \fI--post302\fP and \fI--post303\fP. .IP "--login-options " (IMAP POP3 SMTP) Specify the login options to use during server authentication. You can use the login options to specify protocol specific options that may be used during authentication. At present only IMAP, POP3 and SMTP support login options. For more information about the 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. Added in 7.34.0. .IP "--mail-auth
" (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. See also \fI--mail-rcpt\fP and \fI--mail-from\fP. Added in 7.25.0. .IP "--mail-from
" (SMTP) Specify a single address that the given mail should get sent from. See also \fI--mail-rcpt\fP and \fI--mail-auth\fP. Added in 7.20.0. .IP "--mail-rcpt
" (SMTP) Specify a single address, user name or mailing list name. Repeat this option several times to send to multiple recipients. When performing a mail transfer, the recipient should specify a valid email address to send the mail to. When performing an address verification (VRFY command), the recipient should be specified as the user name or user name and domain (as per Section 3.5 of RFC5321). (Added in 7.34.0) When performing a mailing list expand (EXPN command), the recipient should be specified using the mailing list name, such as "Friends" or "London-Office". (Added in 7.34.0) Added in 7.20.0. .IP "-M, --manual" Manual. Display the huge help text. .IP "--max-filesize " 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. \fBNOTE:\fP 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. See also \fI--limit-rate\fP. .IP "--max-redirs " (HTTP) Set maximum number of redirection-followings allowed. When \fI-L, --location\fP is used, is 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 unlimited. If this option is used several times, the last one will be used. .IP "-m, --max-time