# curl - transfer a URL - man(1) - [phpMan] > **TLDR:** Transfers data from or to a server. > - Make an HTTP GET request and dump the contents in `stdout`: `curl {{https://example.com}}` - Make an HTTP GET request, follow any `3xx` redirects, and dump the reply headers and contents to `stdout`: `curl {{-L|--location}} {{-D|--dump-header}} - {{https://example.com}}` - Download a file, saving the output under the filename indicated by the URL: `curl {{-O|--remote-name}} {{https://example.com/filename.zip}}` - Send form-encoded data (POST request of type `application/x-www-form-urlencoded`). Use `--data @file_name` or `--data @'-'` to read from `stdin`: `curl {{-X|--request}} POST {{-d|--data}} '{{name=bob}}' {{http://example.com/form}}` - Send a request with an extra header, using a custom HTTP method and over a proxy (such as BurpSuite), ignoring insecure self-signed certificates: `curl {{-k|--insecure}} {{-x|--proxy}} {{http://127.0.0.1:8080}} {{-H|--header}} '{{Authorization: Bearer token}}' {{-X|--request}} {{GET|PUT|POST|DELETE|PATCH|...}} {{https://example.com}}` - Send data in JSON format, specifying the appropriate Content-Type header: `curl {{-d|--data}} '{{{"name":"bob"}}}' {{-H|--header}} '{{Content-Type: application/json}}' {{http://example.com/users/1234}}` - Pass client certificate and private key for the request, skipping certificate validation: `curl {{-E|--cert}} {{client.pem}} --key {{key.pem}} {{-k|--insecure}} {{https://example.com}}` - Resolve a hostname to a custom IP address, with verbose output (similar to editing the `/etc/hosts` file for custom DNS resolution): `curl {{-v|--verbose}} --resolve {{example.com}}:{{80}}:{{127.0.0.1}} {{http://example.com}}` *Source: tldr-pages* --- [_curl_(1)](https://www.chedong.com/phpMan.php/man/curl/1/markdown) curl Manual [_curl_(1)](https://www.chedong.com/phpMan.php/man/curl/1/markdown) ## NAME curl - transfer a URL ## SYNOPSIS ### curl [options / URLs] ## DESCRIPTION **curl **is a tool for transferring data from or to a server using URLs. It supports these proto‐ cols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS. curl is powered by libcurl for all transfer-related features. See [_libcurl(3)](https://www.chedong.com/phpMan.php/man/libcurl/3/markdown)_ for details. ## URL The URL syntax is protocol-dependent. You find a detailed description in RFC 3986. If you provide a URL without a leading **protocol:// **scheme, curl guesses what protocol you want. It then defaults to HTTP but assumes others based on often-used host name prefixes. For example, for host names starting with "ftp." curl assumes you want FTP. You can specify any amount of URLs on the command line. They are fetched in a sequential man‐ ner in the specified order unless you use _-Z,_ _--parallel_. You can specify command line op‐ tions and URLs mixed and in any order on the command line. curl attempts to reuse connections when doing multiple transfers, so that getting many files from the same server do not use multiple connects and setup handshakes. This improves speed. Connection reuse can only be done for URLs specified for a single command line invocation and cannot be performed between separate curl runs. Provide an IPv6 zone id in the URL with an escaped percentage sign. Like in "http://[[fe80::3](https://www.chedong.com/phpMan.php/perldoc/fe80%3A%3A3/markdown)%25eth0]/" Everything provided on the command line that is not a command line option or its argument, curl assumes is a URL and treats it as such. ## GLOBBING You can specify multiple URLs or parts of URLs by writing lists within braces or ranges within brackets. We call this "globbing". Provide a list with three different names like this: ".{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: "[1996-1999]/vol[1-4]/part{a,b,c}.html" You can specify a step counter for the ranges to get every Nth number or letter: "[1-100:10].txt" "[a-z:2].txt" When using [] or {} sequences when invoked from a command line prompt, you probably have to put the full URL within double quotes to avoid the shell from interfering with it. This also goes for other characters treated special, like for example '&', '?' and '*'. Switch off globbing with _-g,_ _--globoff_. ## VARIABLES curl supports command line variables (added in 8.3.0). Set variables with _--variable_ name=content or _--variable_ name@file (where "file" can be stdin if set to a single dash (-)). Variable contents can expanded in option parameters using "{{name}}" (without the quotes) if the option name is prefixed with "--expand-". This gets the contents of the variable "name" inserted, or a blank if the name does not exist as a variable. Insert "{{" verbatim in the string by prefixing it with a backslash, like "\{{". You an access and expand environment variables by first importing them. You can select to ei‐ ther require the environment variable to be set or you can provide a default value in case it is not already set. Plain _--variable_ %name imports the variable called 'name' but exits with an error if that environment variable is not already set. To provide a default value if it is not set, use _--variable_ %name=content or _--variable_ %name@content. Example. Get the USER environment variable into the URL, fail if USER is not set: --variable '%USER' --expand-url = "{{USER}}/method" When expanding variables, curl supports a set of functions that can make the variable con‐ tents more convenient to use. It can trim leading and trailing white space with _trim_, it can output the contents as a JSON quoted string with _json_, URL encode the string with _url_ or base64 encode it with _b64_. You apply function to a variable expansion, add them colon sepa‐ rated to the right side of the variable. Variable content holding null bytes that are not en‐ coded when expanded cause error. Example: get the contents of a file called $HOME/.secret into a variable called "fix". Make sure that the content is trimmed and percent-encoded sent as POST data: --variable %HOME --expand-variable fix@{{HOME}}/.secret --expand-data "{{fix:trim:url}}" Command line variables and expansions were added in in 8.3.0. ## OUTPUT If not told otherwise, curl writes the received data to stdout. It can be instructed to in‐ stead save that data into a local file, using the _-o,_ _--output_ or _-O,_ _--remote-name_ options. If curl is given multiple URLs to transfer on the command line, it similarly needs multiple options for where to save them. curl does not parse or otherwise "understand" the content it gets or writes as output. It does no encoding or decoding, unless explicitly asked to with dedicated command line options. ## PROTOCOLS curl supports numerous protocols, or put in URL terms: schemes. Your particular build may not support them all. DICT Lets you lookup words using online dictionaries. FILE Read or write local files. curl does not support accessing file:// URL remotely, but when running on Microsoft Windows using the native UNC approach works. FTP(S) curl supports the File Transfer Protocol with a lot of tweaks and levers. With or without using TLS. GOPHER(S) Retrieve files. HTTP(S) curl supports HTTP with numerous options and variations. It can speak HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build options and the correct command line op‐ tions. IMAP(S) Using the mail reading protocol, curl can "download" emails for you. With or without using TLS. LDAP(S) curl can do directory lookups for you, with or without TLS. MQTT curl supports MQTT version 3. Downloading over MQTT equals "subscribe" to a topic while uploading/posting equals "publish" on a topic. MQTT over TLS is not supported (yet). POP3(S) Downloading from a pop3 server means getting a mail. With or without using TLS. RTMP(S) The Realtime Messaging Protocol is primarily used to serve streaming media and curl can download it. RTSP curl supports RTSP 1.0 downloads. SCP curl supports SSH version 2 scp transfers. SFTP curl supports SFTP (draft 5) done over SSH version 2. SMB(S) curl supports SMB version 1 for upload and download. SMTP(S) Uploading contents to an SMTP server means sending an email. With or without TLS. TELNET Telling curl to fetch a telnet URL starts an interactive session where it sends what it reads on stdin and outputs what the server sends it. TFTP curl can do TFTP downloads and uploads. ## PROGRESS METER curl normally displays a progress meter during operations, indicating the amount of trans‐ ferred data, transfer speeds and estimated time left, etc. The progress meter displays the transfer rate in bytes per second. The suffixes (k, M, G, T, P) are 1024 based. For example 1k is 1024 bytes. 1M is 1048576 bytes. curl displays this data to the terminal by default, so if you invoke curl to do an operation and it is about to write data to the terminal, it _disables_ the progress meter as otherwise it would mess up the output mixing progress meter and response data. If you want a progress meter for HTTP POST or PUT requests, you need to redirect the response output to a file, using shell redirect (>), _-o,_ _--output_ or similar. This does not apply to FTP upload as that operation does not spit out any response data to the terminal. If you prefer a progress "bar" instead of the regular meter, _-#,_ _--progress-bar_ is your friend. You can also disable the progress meter completely with the _-s,_ _--silent_ option. ## VERSION This man page describes curl 8.5.0. If you use a later version, chances are this man page does not fully document it. If you use an earlier version, this document tries to include version information about which specific version that introduced changes. You can always learn which the latest curl version is by running curl The online version of this man page is always showing the latest incarnation: ## OPTIONS Options start with one or two dashes. Many of the options require an additional value next to them. If provided text does not start with a dash, it is presumed to be and treated as a URL. The short "single-dash" form of the options, -d for example, may be used with or without a space between it and its value, although a space is a recommended separator. The long "dou‐ ble-dash" form, _-d,_ _--data_ for example, requires a space between it and its value. Short version options that do not need any additional values can be used immediately next to each other, like for example you can specify all the options _-O_, _-L_ and _-v_ at once as _-OLv_. In general, all boolean options are enabled with --**option **and yet again disabled with --**no-**option. That is, you use the same option name but prefix it with "no-". However, in this list we mostly only list and show the _--option_ version of them. When _-:,_ _--next_ is used, it resets the parser state and you start again with a clean option state, except for the options that are "global". Global options retain their values and mean‐ ing even after _-:,_ _--next_. The following options are global: _--fail-early_, _--libcurl_, _--parallel-immediate_, _-Z,_ _--paral‐_ _lel_, _-#,_ _--progress-bar_, _--rate_, _-S,_ _--show-error_, _--stderr_, _--styled-output_, _--trace-ascii_, _--trace-config_, _--trace-ids_, _--trace-time_, _--trace_ and _-v,_ _--verbose_. ### --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. If _--abstract-unix-socket_ is provided several times, the last set value is used. Example: curl --abstract-unix-socket socketpath See also _--unix-socket_. Added in 7.53.0. ### --alt-svc (HTTPS) This option enables the alt-svc parser in curl. If the file name points to an existing alt-svc cache file, that gets used. After a completed transfer, the cache is saved to the file name again if it has been modified. Specify a "" file name (zero length) to avoid loading/saving and make curl just handle the cache in memory. If this option is used several times, curl loads contents from all the files but the last one is used for saving. _--alt-svc_ can be used several times in a command line Example: curl --alt-svc svc.txt See also _--resolve_ and _--connect-to_. Added in 7.64.1. ### --anyauth (HTTP) Tells curl to figure out authentication method by itself, and use the most se‐ cure one the remote site claims to support. This is done by first doing a request and checking the response-headers, thus possibly inducing an extra network round-trip. This is used instead of setting a specific authentication method, which you can do with _--basic_, _--digest_, _--ntlm_, and _--negotiate_. Using _--anyauth_ is not recommended if you do uploads from stdin, since it may require data to be sent twice and then the client must be able to rewind. If the need should arise when uploading from stdin, the upload operation fails. Used together with _-u,_ _--user_. Providing _--anyauth_ multiple times has no extra effect. Example: curl --anyauth --user me:pwd See also _--proxy-anyauth_, _--basic_ and _--digest_. ### -a, --append (FTP SFTP) When used in an upload, this option makes curl append to the target file instead of overwriting it. If the remote file does not exist, it is created. Note that this flag is ignored by some SFTP servers (including OpenSSH). Providing _-a,_ _--append_ multiple times has no extra effect. Disable it again with --no-append. Example: curl --upload-file local --append ftp://example.com/ See also _-r,_ _--range_ and _-C,_ _--continue-at_. --aws-sigv4 Use AWS V4 signature authentication in the transfer. The provider argument is a string that is used by the algorithm when creating outgoing authentication headers. The region argument is a string that points to a geographic area of a resources col‐ lection (region-code) when the region name is omitted from the endpoint. The service argument is a string that points to a function provided by a cloud (ser‐ vice-code) when the service name is omitted from the endpoint. If _--aws-sigv4_ is provided several times, the last set value is used. Example: curl --aws-sigv4 "aws:amz:us-east-2:es" --user "key:secret" See also _--basic_ and _-u,_ _--user_. Added in 7.75.0. ### --basic (HTTP) Tells curl to use HTTP Basic authentication with the remote host. This is the default and this option is usually pointless, unless you use it to override a previ‐ ously set option that sets a different authentication method (such as _--ntlm_, _--di‐_ _gest_, or _--negotiate_). Used together with _-u,_ _--user_. Providing _--basic_ multiple times has no extra effect. Example: curl -u name:password --basic See also _--proxy-basic_. ### --ca-native (TLS) Tells curl to use the CA store from the native operating system to verify the peer. By default, curl otherwise uses a CA store provided in a single file or direc‐ tory, but when using this option it interfaces the operating system's own vault. This option only works for curl on Windows when built to use OpenSSL. When curl on Windows is built to use Schannel, this feature is implied and curl then only uses the native CA store. curl built with wolfSSL also supports this option (added in 8.3.0). Providing _--ca-native_ multiple times has no extra effect. Disable it again with --no-ca-native. Example: curl --ca-native See also _--cacert_, _--capath_ and _-k,_ _--insecure_. Added in 8.2.0. ### --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. Nor‐ mally 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 automatically looks for a CA certs file named 'curl-ca-bundle.crt', either in the same directory as curl.exe, or in the Current Working Directory, or in any folder along your PATH. (iOS and macOS only) If curl is built against Secure Transport, then this option is supported for backward compatibility with other SSL engines, but it should not be set. If the option is not set, then curl uses the certificates in the system and user Key‐ chain to verify the peer, which is the preferred method of verifying the peer's cer‐ tificate chain. (Schannel only) This option is supported for Schannel in Windows 7 or later (added in 7.60.0). This option is supported for backward compatibility with other SSL engines; instead it is recommended to use Windows' store of root certificates (the default for Schannel). If _--cacert_ is provided several times, the last set value is used. Example: curl --cacert CA-file.txt See also _--capath_ and _-k,_ _--insecure_. ### --capath (TLS) Tells curl to use the specified certificate directory to verify the peer. Multi‐ ple 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 direc‐ tory 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 is ignored. If _--capath_ is provided several times, the last set value is used. Example: curl --capath /local/directory See also _--cacert_ and _-k,_ _--insecure_. ### --cert-status (TLS) Tells curl to verify the status of the server certificate by using the Certifi‐ cate 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 and GnuTLS backends. Providing _--cert-status_ multiple times has no extra effect. Disable it again with --no-cert-status. Example: curl --cert-status See also _--pinnedpubkey_. ### --cert-type (TLS) Tells curl what type the provided client certificate is using. PEM, DER, ENG and P12 are recognized types. The default type depends on the TLS backend and is usually PEM, however for Secure Transport and Schannel it is P12. If _-E,_ _--cert_ is a pkcs11: URI then ENG is the de‐ fault type. If _--cert-type_ is provided several times, the last set value is used. Example: curl --cert-type PEM --cert file See also _-E,_ _--cert_, _--key_ and _--key-type_. -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 is not specified, it is queried for on the terminal. Note that this option assumes a certificate file that is the private key and the client certificate concate‐ nated. See _-E,_ _--cert_ and _--key_ to specify them independently. In the portion of the argument, you must escape the character ":" as "\:" so that it is not recognized as the password delimiter. Similarly, you must es‐ cape the character "\" as "\\" so that it is not recognized as an escape character. If curl is built against OpenSSL library, and the engine pkcs11 is available, then a PKCS#11 URI (RFC 7512) can be used to specify a certificate located in a PKCS#11 de‐ vice. A string beginning with "pkcs11:" is interpreted as a PKCS#11 URI. If a PKCS#11 URI is provided, then the _--engine_ option is set as "pkcs11" if none was provided and the _--cert-type_ option is set as "ENG" if none was provided. (iOS and macOS only) If curl is built against Secure Transport, then the certificate string can either be the name of a certificate/private key in the system or user key‐ chain, or the path to a PKCS#12-encoded certificate and private key. If you want to use a file from the current directory, please precede it with "./" prefix, in order to avoid confusion with a nickname. (Schannel only) Client certificates must be specified by a path expression to a cer‐ tificate store. (Loading _PFX_ is not supported; you can import it to a store first). You can use "\\" to refer to a certificate in the system certificates store, for example, _"Curren‐_ _tUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a"_. Thumbprint is usually a SHA-1 hex string which you can see in certificate details. Following store locations are sup‐ ported: _CurrentUser_, _LocalMachine_, _CurrentService_, _Services_, _CurrentUserGroupPolicy_, _LocalMachineGroupPolicy_ and _LocalMachineEnterprise_. If _-E,_ _--cert_ is provided several times, the last set value is used. Example: curl --cert certfile --key keyfile See also _--cert-type_, _--key_ and _--key-type_. ### --ciphers (TLS) Specifies which ciphers to use in the connection. The list of ciphers must spec‐ ify valid ciphers. Read up on SSL cipher list details on this URL: If _--ciphers_ is provided several times, the last set value is used. Example: curl --ciphers ECDHE-ECDSA-AES256-CCM8 See also _--tlsv1.3_, _--tls13-ciphers_ and _--proxy-ciphers_. ### --compressed-ssh (SCP SFTP) Enables built-in SSH compression. This is a request, not an order; the server may or may not do it. Providing _--compressed-ssh_ multiple times has no extra effect. Disable it again with --no-compressed-ssh. Example: curl --compressed-ssh sftp://example.com/ See also _--compressed_. Added in 7.56.0. ### --compressed (HTTP) Request a compressed response using one of the algorithms curl supports, and automatically decompress the content. Response headers are not modified when saved, so if they are "interpreted" separately again at a later point they might appear to be saying that the content is (still) com‐ pressed; while in fact it has already been decompressed. If this option is used and the server sends an unsupported encoding, curl reports an error. This is a request, not an order; the server may or may not deliver data com‐ pressed. Providing _--compressed_ multiple times has no extra effect. Disable it again with --no-compressed. Example: curl --compressed See also _--compressed-ssh_. ### -K, --config Specify a text file to read curl arguments from. The command line arguments found in the text file are used as if they were provided on the command line. Options and their parameters must be specified on the same line in the file, separated by whitespace, colon, or the equals sign. Long option names can optionally be given in the config file without the initial double dashes and if so, the colon or equals char‐ acters can be used as separators. If the option is specified with one or two dashes, there can be no colon or equals character between the option and its parameter. If the parameter contains whitespace or starts with a colon (:) or equals sign (=), it must be specified enclosed within double quotes ("). Within double quotes the follow‐ ing escape sequences are available: \\, \", \t, \n, \r and \v. A backslash preceding any other letter is ignored. If the first non-blank column of a config line is a '#' character, that line is treated as a comment. Only write one option per physical line in the config file. A single line is required to be no more than 10 megabytes (since 8.2.0). Specify the filename to _-K,_ _--config_ as '-' to make curl read the file from stdin. Note that to be able to specify a URL in the config file, you need to specify it using the _--url_ option, and not by simply writing the URL on its own line. So, it could look similar to this: url = "" # --- 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 = "" # --- End of example file --- When curl is invoked, it (unless _-q,_ _--disable_ is used) checks for a default config file and uses it if found, even when _-K,_ _--config_ is used. The default config file is checked for in the following places in this order: 1) **"$CURL_HOME/.curlrc"** 2) **"$XDG_CONFIG_HOME/curlrc" **(Added in 7.73.0) 3) **"$HOME/.curlrc"** 4) Windows: **"%USERPROFILE%\.curlrc"** 5) Windows: **"%APPDATA%\.curlrc"** 6) Windows: "%USERPROFILE%\Application Data\.curlrc" 7) Non-Windows: use getpwuid to find the home directory 8) On Windows, if it finds no _.curlrc_ file in the sequence described above, it checks for one in the same dir the curl executable is placed. On Windows two filenames are checked per location: _.curlrc_ and __curlrc_, preferring the former. Older versions on Windows checked for __curlrc_ only. _-K,_ _--config_ can be used several times in a command line Example: curl --config file.txt See also _-q,_ _--disable_. ### --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 continues - if not it exits. This option accepts decimal values. The decimal value needs to be provided using a dot (.) as decimal separator - not the local version even if it might be using another separator. The connection phase is considered complete when the DNS lookup and requested TCP, TLS or QUIC handshakes are done. If _--connect-timeout_ is provided several times, the last set value is used. Examples: curl --connect-timeout 20 curl --connect-timeout 3.14 See also _-m,_ _--max-time_. ### --connect-to For a request to the given HOST1:PORT1 pair, connect to HOST2:PORT2 instead. This op‐ tion 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 con‐ nection. It does NOT affect the hostname/port that is used for TLS/SSL (e.g. SNI, cer‐ tificate verification) or for the application protocols. "HOST1" and "PORT1" may be the empty string, meaning "any host/port". "HOST2" and "PORT2" may also be the empty string, meaning "use the request's original host/port". A "host" specified to this option is compared as a string, so it needs to match the name used in request URL. It can be either numerical such as "127.0.0.1" or the full host name such as "example.org". _--connect-to_ can be used several times in a command line Example: curl --connect-to example.com:443:example.net:8443 See also _--resolve_ and _-H,_ _--header_. ### -C, --continue-at Continue/Resume a previous file transfer at the given offset. The given offset is the exact number of bytes that are skipped, counting from the beginning of the source file before it is transferred to the destination. If used with uploads, the FTP server com‐ mand SIZE is not used by curl. Use "-C -" to tell curl to automatically find out where/how to resume the transfer. It then uses the given output/input files to figure that out. If _-C,_ _--continue-at_ is provided several times, the last set value is used. Examples: curl -C - curl -C 400 See also _-r,_ _--range_. ### -c, --cookie-jar (HTTP) Specify to which file you want curl to write all cookies after a completed op‐ eration. Curl writes all cookies from its in-memory cookie storage to the given file at the end of operations. If no cookies are known, no data is written. The file is created using the Netscape cookie file format. If you set the file name to a single dash, "-", the cookies are written to stdout. The file specified with _-c,_ _--cookie-jar_ is only used for output. No cookies are read from the file. To read cookies, use the _-b,_ _--cookie_ option. Both options can specify the same file. This command line option activates the cookie engine that makes curl record and use cookies. The _-b,_ _--cookie_ option also activates it. If the cookie jar cannot be created or written to, the whole curl operation does not fail or even report an error clearly. Using _-v,_ _--verbose_ gets a warning displayed, but that is the only visible feedback you get about this possibly lethal situation. If _-c,_ _--cookie-jar_ is provided several times, the last set value is used. Examples: curl -c store-here.txt curl -c store-here.txt -b read-these See also _-b,_ _--cookie_. ### -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". This makes curl use the cookie header with this content explicitly in all outgoing request(s). If multiple requests are done due to authentication, followed redirects or similar, they all get this cookie passed on. If no '=' symbol is used in the argument, it is instead treated as a filename to read previously stored cookie from. This option also activates the cookie engine which makes curl record incoming cookies, which may be handy if you are using this in combi‐ nation with the _-L,_ _--location_ option or do multiple URL transfers on the same invoke. If the file name is exactly a minus ("-"), curl instead reads the contents from stdin. The file format of the file to read cookies from should be plain HTTP headers (Set-Cookie style) or the Netscape/Mozilla cookie file format. The file specified with _-b,_ _--cookie_ is only used as input. No cookies are written to the file. To store cookies, use the _-c,_ _--cookie-jar_ option. If you use the Set-Cookie file format and do not specify a domain then the cookie is not sent since the domain never matches. To address this, set a domain in Set-Cookie line (doing that includes subdomains) or preferably: use the Netscape format. Users often want to both read cookies from a file and write updated cookies back to a file, so using both _-b,_ _--cookie_ and _-c,_ _--cookie-jar_ in the same command line is com‐ mon. _-b,_ _--cookie_ can be used several times in a command line Examples: curl -b cookiefile curl -b cookiefile -c cookiefile See also _-c,_ _--cookie-jar_ and _-j,_ _--junk-session-cookies_. ### --create-dirs When used in conjunction with the _-o,_ _--output_ option, curl creates the necessary lo‐ cal directory hierarchy as needed. This option creates the directories mentioned with the _-o,_ _--output_ option combined with the path possibly set with _--output-dir_. If the combined output file name uses no directory, or if the directories it mentions already exist, no directories are created. Created directories are made with mode 0750 on unix style file systems. To create remote directories when using FTP or SFTP, try _--ftp-create-dirs_. Providing _--create-dirs_ multiple times has no extra effect. Disable it again with --no-create-dirs. Example: curl --create-dirs --output local/dir/file See also _--ftp-create-dirs_ and _--output-dir_. ### --create-file-mode (SFTP SCP FILE) When curl is used to create files remotely using one of the supported protocols, this option allows the user to set which 'mode' to set on the file at cre‐ ation time, instead of the default 0644. This option takes an octal number as argument. If _--create-file-mode_ is provided several times, the last set value is used. Example: curl --create-file-mode 0777 -T localfile sftp://example.com/new See also _--ftp-create-dirs_. Added in 7.75.0. --crlf (FTP SMTP) Convert line feeds to carriage return plus line feeds in upload. Useful for MVS (OS/390). (SMTP added in 7.40.0) Providing _--crlf_ multiple times has no extra effect. Disable it again with --no-crlf. Example: curl --crlf -T file ftp://example.com/ See also _-B,_ _--use-ascii_. ### --crlfile (TLS) Provide a file using PEM format with a Certificate Revocation List that may specify peer certificates that are to be considered revoked. If _--crlfile_ is provided several times, the last set value is used. Example: curl --crlfile rejects.txt See also _--cacert_ and _--capath_. ### --curves (TLS) Tells curl to request specific curves to use during SSL session establishment according to RFC 8422, 5.1. Multiple algorithms can be provided by separating them with ":" (e.g. "X25519:P-521"). The parameter is available identically in the "openssl s_client/s_server" utilities. _--curves_ allows a OpenSSL powered curl to make SSL-connections with exactly the (EC) curve requested by the client, avoiding nontransparent client/server negotiations. If this option is set, the default curves list built into OpenSSL are ignored. If _--curves_ is provided several times, the last set value is used. Example: curl --curves X25519 See also _--ciphers_. Added in 7.73.0. ### --data-ascii (HTTP) This is just an alias for _-d,_ _--data_. _--data-ascii_ can be used several times in a command line Example: curl --data-ascii @file See also _--data-binary_, _--data-raw_ and _--data-urlencode_. ### --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 _-d,_ _--data_ does, except that newlines and carriage returns are preserved and conversions are never done. Like _-d,_ _--data_ the default content-type sent to the server is applica‐ tion/x-www-form-urlencoded. If you want the data to be treated as arbitrary binary data by the server then set the content-type to octet-stream: -H "Content-Type: appli‐ cation/octet-stream". If this option is used several times, the ones following the first append data as de‐ scribed in _-d,_ _--data_. _--data-binary_ can be used several times in a command line Example: curl --data-binary @filename See also _--data-ascii_. ### --data-raw (HTTP) This posts data similarly to _-d,_ _--data_ but without the special interpretation of the @ character. _--data-raw_ can be used several times in a command line Examples: curl --data-raw "hello" curl --data-raw "@at@at@" See also _-d,_ _--data_. ### --data-urlencode (HTTP) This posts data, similar to the other _-d,_ _--data_ options with the exception that this performs URL-encoding. To be CGI-compliant, the part should begin with a _name_ followed by a separator and a content specification. The part can be passed to curl using one of the following syntaxes: content This makes curl URL-encode the content and pass that on. Just be careful so that the content does not contain any = or @ symbols, as that makes the syntax match one of the other cases below! =content This makes curl URL-encode the content and pass that on. The preceding = symbol is not included in the data. name=content This makes curl URL-encode the content part and pass that on. Note that the name part is expected to be URL-encoded already. @filename This makes curl load data from the given file (including any newlines), URL-en‐ code that data and pass it on in the POST. name@filename This makes curl load data from the given file (including any newlines), URL-en‐ code that data and pass it on in the POST. The name part gets an equal sign ap‐ pended, resulting in _name=urlencoded-file-content_. Note that the name is ex‐ pected to be URL-encoded already. _--data-urlencode_ can be used several times in a command line Examples: curl --data-urlencode name=val curl --data-urlencode =encodethis curl --data-urlencode name@file curl --data-urlencode @fileonly See also _-d,_ _--data_ and _--data-raw_. ### -d, --data (HTTP MQTT) Sends the specified data in a POST request to the HTTP server, in the same way that a browser does when a user has filled in an HTML form and presses the submit button. This makes curl pass the data to the server using the content-type applica‐ tion/x-www-form-urlencoded. Compare to _-F,_ _--form_. _--data-raw_ is almost the same but does not have a special interpretation of the @ character. To post data purely binary, you should instead use the _--data-binary_ op‐ tion. To URL-encode the value of a form field you may use _--data-urlencode_. If any of these options is used more than once on the same command line, the data pieces specified are merged with a separating &-symbol. Thus, using '-d name=daniel -d skill=lousy' would generate a post chunk that looks like 'name=daniel&skill=lousy'. If you start the data with the letter @, the rest should be a file name to read the data from, or - if you want curl to read the data from stdin. Posting data from a file named 'foobar' would thus be done with _-d,_ _--data_ @foobar. When _-d,_ _--data_ is told to read from a file like that, carriage returns and newlines are stripped out. If you do not want the @ character to have a special interpretation use _--data-raw_ instead. The data for this option is passed on to the server exactly as provided on the command line. curl does not convert, change or improve it. It is up to the user to provide the data in the correct form. _-d,_ _--data_ can be used several times in a command line Examples: curl -d "name=curl" curl -d "name=curl" -d "tool=cmdline" curl -d @filename See also _--data-binary_, _--data-urlencode_ and _--data-raw_. This option is mutually ex‐ clusive to _-F,_ _--form_ and _-I,_ _--head_ and _-T,_ _--upload-file_. ### --delegation (GSS/kerberos) Set LEVEL to tell the server what it is allowed to delegate when it comes to user credentials. none Do not allow any delegation. policy Delegates if and only if the OK-AS-DELEGATE flag is set in the Kerberos service ticket, which is a matter of realm policy. always Unconditionally allow the server to delegate. If _--delegation_ is provided several times, the last set value is used. Example: curl --delegation "none" See also _-k,_ _--insecure_ and _--ssl_. ### --digest (HTTP) Enables HTTP Digest authentication. This is an authentication scheme that pre‐ vents the password from being sent over the wire in clear text. Use this in combina‐ tion with the normal _-u,_ _--user_ option to set user name and password. Providing _--digest_ multiple times has no extra effect. Disable it again with --no-di‐ gest. Example: curl -u name:password --digest See also _-u,_ _--user_, _--proxy-digest_ and _--anyauth_. This option is mutually exclusive to _--basic_ and _--ntlm_ and _--negotiate_. ### --disable-eprt (FTP) Tell curl to disable the use of the EPRT and LPRT commands when doing active FTP transfers. Curl normally first attempts to use EPRT before using PORT, but with this option, it uses PORT right away. EPRT is an extension to the original FTP protocol, and does not work on all servers, but enables more functionality in a better way than the traditional PORT command. --eprt can be used to explicitly enable EPRT again and --no-eprt is an alias for _--disable-eprt_. If the server is accessed using IPv6, this option has no effect as EPRT is necessary then. Disabling EPRT only changes the active behavior. If you want to switch to passive mode you need to not use _-P,_ _--ftp-port_ or force it with _--ftp-pasv_. Providing _--disable-eprt_ multiple times has no extra effect. Disable it again with --no-disable-eprt. Example: curl --disable-eprt ftp://example.com/ See also _--disable-epsv_ and _-P,_ _--ftp-port_. ### --disable-epsv (FTP) Tell curl to disable the use of the EPSV command when doing passive FTP trans‐ fers. Curl normally first attempts to use EPSV before PASV, but with this option, it does not try EPSV. --epsv can be used to explicitly enable EPSV again and --no-epsv is an alias for _--disable-epsv_. If the server is an IPv6 host, this option has no effect as EPSV is necessary then. Disabling EPSV only changes the passive behavior. If you want to switch to active mode you need to use _-P,_ _--ftp-port_. Providing _--disable-epsv_ multiple times has no extra effect. Disable it again with --no-disable-epsv. Example: curl --disable-epsv ftp://example.com/ See also _--disable-eprt_ and _-P,_ _--ftp-port_. ### -q, --disable If used as the **first **parameter on the command line, the _curlrc_ config file is not read or used. See the _-K,_ _--config_ for details on the default config file search path. Prior to 7.50.0 curl supported the short option name _q_ but not the long option name _disable_. Providing _-q,_ _--disable_ multiple times has no extra effect. Disable it again with --no-disable. Example: curl -q See also _-K,_ _--config_. ### --disallow-username-in-url (HTTP) This tells curl to exit if passed a URL containing a username. This is probably most useful when the URL is being provided at runtime or similar. Providing _--disallow-username-in-url_ multiple times has no extra effect. Disable it again with --no-disallow-username-in-url. Example: curl --disallow-username-in-url See also _--proto_. Added in 7.61.0. ### --dns-interface (DNS) Tell curl to send outgoing DNS requests through . This option is a counterpart to _--interface_ (which does not affect DNS). The supplied string must be an interface name (not an address). If _--dns-interface_ is provided several times, the last set value is used. Example: curl --dns-interface eth0 See also _--dns-ipv4-addr_ and _--dns-ipv6-addr_. _--dns-interface_ requires that the under‐ lying libcurl was built to support c-ares. ### --dns-ipv4-addr
(DNS) Tell curl to bind to a specific IP address when making IPv4 DNS requests, so that the DNS requests originate from this address. The argument should be a single IPv4 address. If _--dns-ipv4-addr_ is provided several times, the last set value is used. Example: curl --dns-ipv4-addr 10.1.2.3 See also _--dns-interface_ and _--dns-ipv6-addr_. _--dns-ipv4-addr_ requires that the under‐ lying libcurl was built to support c-ares. ### --dns-ipv6-addr
(DNS) Tell curl to bind to a specific IP address when making IPv6 DNS requests, so that the DNS requests originate from this address. The argument should be a single IPv6 address. If _--dns-ipv6-addr_ is provided several times, the last set value is used. Example: curl --dns-ipv6-addr 2a04:[4e42::561](https://www.chedong.com/phpMan.php/perldoc/4e42%3A%3A561/markdown) See also _--dns-interface_ and _--dns-ipv4-addr_. _--dns-ipv6-addr_ requires that the under‐ lying libcurl was built to support c-ares. ### --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 _:_ after each IP address. If _--dns-servers_ is provided several times, the last set value is used. Example: curl --dns-servers 192.168.0.1,192.168.0.2 See also _--dns-interface_ and _--dns-ipv4-addr_. _--dns-servers_ requires that the underly‐ ing libcurl was built to support c-ares. ### --doh-cert-status Same as _--cert-status_ but used for DoH (DNS-over-HTTPS). Providing _--doh-cert-status_ multiple times has no extra effect. Disable it again with --no-doh-cert-status. Example: curl --doh-cert-status --doh-url See also _--doh-insecure_. Added in 7.76.0. ### --doh-insecure Same as _-k,_ _--insecure_ but used for DoH (DNS-over-HTTPS). Providing _--doh-insecure_ multiple times has no extra effect. Disable it again with --no-doh-insecure. Example: curl --doh-insecure --doh-url See also _--doh-url_. Added in 7.76.0. ### --doh-url Specifies which DNS-over-HTTPS (DoH) server to use to resolve hostnames, instead of using the default name resolver mechanism. The URL must be HTTPS. Some SSL options that you set for your transfer also applies to DoH since the name lookups take place over SSL. However, the certificate verification settings are not inherited but are controlled separately via _--doh-insecure_ and _--doh-cert-status_. This option is unset if an empty string "" is used as the URL. (Added in 7.85.0) If _--doh-url_ is provided several times, the last set value is used. Example: curl --doh-url See also _--doh-insecure_. Added in 7.62.0. ### -D, --dump-header (HTTP FTP) Write the received protocol headers to the specified file. If no headers are received, the use of this option creates an empty file. When used in FTP, the FTP server response lines are considered being "headers" and thus are saved there. Having multiple transfers in one set of operations (i.e. the URLs in one _-:,_ _--next_ clause), appends them to the same file, separated by a blank line. If _-D,_ _--dump-header_ is provided several times, the last set value is used. Example: curl --dump-header store.txt See also _-o,_ _--output_. ### --egd-file (TLS) Deprecated option (added in 7.84.0). Prior to that it only had an effect on curl if built to use old versions of OpenSSL. Specify the path name to the Entropy Gathering Daemon socket. The socket is used to seed the random engine for SSL connections. If _--egd-file_ is provided several times, the last set value is used. Example: curl --egd-file /random/here See also _--random-file_. ### --engine (TLS) Select the OpenSSL crypto engine to use for cipher operations. Use _--engine_ list to print a list of build-time supported engines. Note that not all (and possibly none) of the engines may be available at runtime. If _--engine_ is provided several times, the last set value is used. Example: curl --engine flavor See also _--ciphers_ and _--curves_. ### --etag-compare (HTTP) This option makes a conditional HTTP request for the specific ETag read from the given file by sending a custom If-None-Match header using the stored ETag. For correct results, make sure that the specified file contains only a single line with the desired ETag. An empty file is parsed as an empty ETag. Use the option _--etag-save_ to first save the ETag from a response, and then use this option to compare against the saved ETag in a subsequent request. If _--etag-compare_ is provided several times, the last set value is used. Example: curl --etag-compare etag.txt See also _--etag-save_ and _-z,_ _--time-cond_. Added in 7.68.0. ### --etag-save (HTTP) This option saves an HTTP ETag to the specified file. An ETag is a caching re‐ lated header, usually returned in a response. If no ETag is sent by the server, an empty file is created. If _--etag-save_ is provided several times, the last set value is used. Example: curl --etag-save storetag.txt See also _--etag-compare_. Added in 7.68.0. ### --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 waits one second. This option accepts decimal values! When curl stops waiting, it continues as if the response has been received. The decimal value needs to provided using a dot (.) as decimal separator - not the lo‐ cal version even if it might be using another separator. If _--expect100-timeout_ is provided several times, the last set value is used. Example: curl --expect100-timeout 2.5 -T file See also _--connect-timeout_. ### --fail-early Fail and exit on the first detected transfer error. When curl is used to do multiple transfers on the command line, it attempts to operate on each given URL, one by one. By default, it ignores errors if there are more URLs given and the last URL's success determines the error code curl returns. So early failures are "hidden" by subsequent successful transfers. Using this option, curl instead returns an error on the first transfer that fails, in‐ dependent of the amount of URLs that are given on the command line. This way, no transfer failures go undetected by scripts and similar. This option does not imply _-f,_ _--fail_, which causes transfers to fail due to the server's HTTP status code. You can combine the two options, however note _-f,_ _--fail_ is not global and is therefore contained by _-:,_ _--next_. This option is global and does not need to be specified for each use of --next. Providing _--fail-early_ multiple times has no extra effect. Disable it again with --no-fail-early. Example: curl --fail-early See also _-f,_ _--fail_ and _--fail-with-body_. Added in 7.52.0. ### --fail-with-body (HTTP) Return an error on server errors where the HTTP response code is 400 or greater). In normal cases when an HTTP server fails to deliver a document, it returns an HTML document stating so (which often also describes why and more). This flag al‐ lows curl to output and save that content but also to return error 22. This is an alternative option to _-f,_ _--fail_ which makes curl fail for the same circum‐ stances but without saving the content. Providing _--fail-with-body_ multiple times has no extra effect. Disable it again with --no-fail-with-body. Example: curl --fail-with-body See also _-f,_ _--fail_ and _--fail-early_. This option is mutually exclusive to _-f,_ _--fail_. Added in 7.76.0. ### -f, --fail (HTTP) Fail fast with no output at all on server errors. This is useful to enable scripts and users to better deal with failed attempts. In normal cases when an HTTP server fails to deliver a document, it returns an HTML document stating so (which of‐ ten also describes why and more). This flag prevents curl from outputting that and re‐ turn error 22. This method is not fail-safe and there are occasions where non-successful response codes slip through, especially when authentication is involved (response codes 401 and 407). Providing _-f,_ _--fail_ multiple times has no extra effect. Disable it again with --no-fail. Example: curl --fail See also _--fail-with-body_ and _--fail-early_. This option is mutually exclusive to _--fail-with-body_. ### --false-start (TLS) Tells curl to use false start during the TLS handshake. False start is a mode where a TLS client starts sending application data before verifying the server's Fin‐ ished message, thus saving a round trip when performing a full handshake. This is currently only implemented in the Secure Transport (on iOS 7.0 or later, or OS X 10.9 or later) backend. Providing _--false-start_ multiple times has no extra effect. Disable it again with --no-false-start. Example: curl --false-start See also _--tcp-fastopen_. ### --form-escape (HTTP) Tells curl to pass on names of multipart form fields and files using back‐ slash-escaping instead of percent-encoding. If _--form-escape_ is provided several times, the last set value is used. Example: curl --form-escape -F 'field\name=curl' -F 'file=@load"this' See also _-F,_ _--form_. Added in 7.81.0. ### --form-string (HTTP SMTP IMAP) Similar to _-F,_ _--form_ except that the value string for the named pa‐ rameter is used literally. Leading '@' and '<' characters, and the ';type=' string in the value have no special meaning. Use this in preference to _-F,_ _--form_ if there is any possibility that the string value may accidentally trigger the '@' or '<' features of _-F,_ _--form_. _--form-string_ can be used several times in a command line Example: curl --form-string "data" See also _-F,_ _--form_. ### -F, --form (HTTP SMTP IMAP) For HTTP protocol family, this lets curl emulate a filled-in form in which a user has pressed the submit button. This causes curl to POST data using the Content-Type multipart/form-data according to RFC 2388. For SMTP and IMAP protocols, this is the means to compose a multipart mail message to transmit. This enables uploading of binary files etc. To force the 'content' part to be a file, prefix the file name with an @ sign. To just get the content part from a file, prefix the file name with the symbol <. The difference between @ and < is then that @ makes a file get attached in the post as a file upload, while the < makes a text field and just get the contents for that text field from a file. Tell curl to read content from stdin instead of a file by using - as filename. This goes for both @ and < constructs. When stdin is used, the contents is buffered in mem‐ ory first by curl to determine its size and allow a possible resend. Defining a part's data from a named non-regular file (such as a named pipe or similar) is not subject to buffering and is instead read at transmission time; since the full size is unknown be‐ fore the transfer starts, such data is sent as chunks by HTTP and rejected by IMAP. Example: send an image to an HTTP server, where 'profile' is the name of the form-field to which the file **portrait.jpg **is the input: curl -F profile=@portrait.jpg Example: send your name and shoe size in two text fields to the server: curl -F name=John -F shoesize=11 Example: send your essay in a text field to the server. Send it as a plain text field, but get the contents for it from a local file: curl -F "story= 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 file‐ name=, like this: curl -F "file=@localfile;filename=nameinpost" example.com If filename/path contains ',' or ';', it must be quoted by double-quotes like: curl -F "file=@\"local,file\";filename=\"name;in;post\"" example.com or curl -F 'file=@"local,file";filename="name;in;post"' example.com Note that if a filename/path is quoted by double-quotes, any double-quote or backslash within the filename must be escaped by backslash. Quoting must also be applied to non-file data if it contains semicolons, lead‐ ing/trailing spaces or leading double quotes: curl -F 'colors="red; green; blue";type=text/x-myapp' example.com You can add custom headers to the field by setting headers=, like curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com or curl -F "submit=OK;headers=@headerfile" example.com The headers= keyword may appear more that once and above notes about quoting apply. When headers are read from a file, Empty lines and lines starting with '#' are com‐ ments and ignored; each header can be folded by splitting between two words and start‐ ing the continuation line with a space; embedded carriage-returns and trailing spaces are stripped. Here is an example of a header file contents: # This file contain two headers. X-header-1: this is a header # The following header is folded. X-header-2: this is another header To support sending multipart mail messages, the syntax is extended as follows: - name can be omitted: the equal sign is the first character of the argument, - if data starts with '(', this signals to start a new multipart: it can be followed by a content type specification. - a multipart can be terminated with a '=)' argument. Example: the following command sends an SMTP mime email consisting in an inline part in two alternative formats: plain text and HTML. It attaches a text file: curl -F '=(;type=multipart/alternative' \ -F '=plain text message' \ -F '= HTML message;type=text/html' \ -F '=)' -F '=@textfile.txt' ... smtp://example.com Data can be encoded for transfer using encoder=. Available encodings are _binary_ and _8bit_ that do nothing else than adding the corresponding Content-Transfer-Encoding header, _7bit_ that only rejects 8-bit characters with a transfer error, _quoted-print‐_ _able_ and _base64_ that encodes data according to the corresponding schemes, limiting lines length to 76 characters. Example: send multipart mail with a quoted-printable text message and a base64 at‐ tached file: curl -F '=text message;encoder=quoted-printable' \ -F '=@localfile;encoder=base64' ... smtp://example.com See further examples and details in the MANUAL. _-F,_ _--form_ can be used several times in a command line Example: curl --form "name=curl" --form "file=@loadthis" See also _-d,_ _--data_, _--form-string_ and _--form-escape_. This option is mutually exclu‐ sive to _-d,_ _--data_ and _-I,_ _--head_ and _-T,_ _--upload-file_. ### --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 _--ftp-account_ is provided several times, the last set value is used. Example: curl --ftp-account "mr.robot" ftp://example.com/ See also _-u,_ _--user_. ### --ftp-alternative-to-user (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 cer‐ tificate, using "SITE AUTH" tells the server to retrieve the username from the cer‐ tificate. If _--ftp-alternative-to-user_ is provided several times, the last set value is used. Example: curl --ftp-alternative-to-user "U53r" ftp://example.com See also _--ftp-account_ and _-u,_ _--user_. ### --ftp-create-dirs (FTP SFTP) When an FTP or SFTP URL/operation uses a path that does not currently exist on the server, the standard behavior of curl is to fail. Using this option, curl in‐ stead attempts to create missing directories. Providing _--ftp-create-dirs_ multiple times has no extra effect. Disable it again with --no-ftp-create-dirs. Example: curl --ftp-create-dirs -T file ftp://example.com/remote/path/file See also _--create-dirs_. ### --ftp-method (FTP) Control what method curl should use to reach a file on an FTP(S) server. The method argument should be one of the following alternatives: multicwd curl does a single CWD operation for each path part in the given URL. For deep hierarchies this means many commands. This is how RFC 1738 says it should be done. This is the default but the slowest behavior. nocwd curl does no CWD at all. curl does SIZE, RETR, STOR etc and give a full path to the server for all these commands. This is the fastest behavior. singlecwd curl does one CWD with the full target directory and then operates on the file "normally" (like in the multicwd case). This is somewhat more standards compli‐ ant than 'nocwd' but without the full penalty of 'multicwd'. If _--ftp-method_ is provided several times, the last set value is used. Examples: curl --ftp-method multicwd ftp://example.com/dir1/dir2/file curl --ftp-method nocwd ftp://example.com/dir1/dir2/file curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file See also _-l,_ _--list-only_. ### --ftp-pasv (FTP) Use passive mode for the data connection. Passive is the internal default behav‐ ior, but using this option can be used to override a previous _-P,_ _--ftp-port_ option. Reversing an enforced passive really is not doable but you must then instead enforce the correct _-P,_ _--ftp-port_ again. Passive mode means that curl tries the EPSV command first and then PASV, unless _--dis‐_ _able-epsv_ is used. Providing _--ftp-pasv_ multiple times has no extra effect. Disable it again with --no-ftp-pasv. Example: curl --ftp-pasv ftp://example.com/ See also _--disable-epsv_. ### -P, --ftp-port
(FTP) Reverses the default initiator/listener roles when connecting with FTP. This op‐ tion 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: interface e.g. "eth0" to specify which interface's IP address you want to use (Unix only) IP address e.g. "192.168.10.1" to specify the exact IP address host name e.g. "my.host.domain" to specify the machine - make curl pick the same IP address that is already used for the control connec‐ tion Disable the use of PORT with _--ftp-pasv_. Disable the attempt to use the EPRT command instead of PORT by using _--disable-eprt_. EPRT is really PORT++. You can also append ":[start]-[end]" to the right of the address, to tell curl what TCP port range to use. That means you specify a port range, from a lower to a higher number. A single number works as well, but do note that it increases the risk of fail‐ ure since the port may not be available. If _-P,_ _--ftp-port_ is provided several times, the last set value is used. Examples: curl -P - ftp:/example.com curl -P eth0 ftp:/example.com curl -P 192.168.0.2 ftp:/example.com See also _--ftp-pasv_ and _--disable-eprt_. ### --ftp-pret (FTP) Tell curl to send a PRET command before PASV (and EPSV). Certain FTP servers, mainly drftpd, require this non-standard command for directory listings as well as up and downloads in PASV mode. Providing _--ftp-pret_ multiple times has no extra effect. Disable it again with --no-ftp-pret. Example: curl --ftp-pret ftp://example.com/ See also _-P,_ _--ftp-port_ and _--ftp-pasv_. ### --ftp-skip-pasv-ip (FTP) Tell curl to not use the IP address the server suggests in its response to curl's PASV command when curl connects the data connection. Instead curl reuses the same IP address it already uses for the control connection. This option is enabled by default (added in 7.74.0). This option has no effect if PORT, EPRT or EPSV is used instead of PASV. Providing _--ftp-skip-pasv-ip_ multiple times has no extra effect. Disable it again with --no-ftp-skip-pasv-ip. Example: curl --ftp-skip-pasv-ip ftp://example.com/ See also _--ftp-pasv_. ### --ftp-ssl-ccc-mode (FTP) Sets the CCC mode. The passive mode does not initiate the shutdown, but instead waits for the server to do it, and does not reply to the shutdown from the server. The active mode initiates the shutdown and waits for a reply from the server. Providing _--ftp-ssl-ccc-mode_ multiple times has no extra effect. Disable it again with --no-ftp-ssl-ccc-mode. Example: curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/ See also _--ftp-ssl-ccc_. ### --ftp-ssl-ccc (FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenticat‐ ing. The rest of the control channel communication is be unencrypted. This allows NAT routers to follow the FTP transaction. The default mode is passive. Providing _--ftp-ssl-ccc_ multiple times has no extra effect. Disable it again with --no-ftp-ssl-ccc. Example: curl --ftp-ssl-ccc ftps://example.com/ See also _--ssl_ and _--ftp-ssl-ccc-mode_. ### --ftp-ssl-control (FTP) Require SSL/TLS for the FTP login, clear for transfer. Allows secure authenti‐ cation, but non-encrypted data transfers for efficiency. Fails the transfer if the server does not support SSL/TLS. Providing _--ftp-ssl-control_ multiple times has no extra effect. Disable it again with --no-ftp-ssl-control. Example: curl --ftp-ssl-control ftp://example.com See also _--ssl_. ### -G, --get When used, this option makes all data specified with _-d,_ _--data_, _--data-binary_ or _--data-urlencode_ to be used in an HTTP GET request instead of the POST request that otherwise would be used. The data is appended to the URL with a '?' separator. If used in combination with _-I,_ _--head_, the POST data is instead appended to the URL with a HEAD request. Providing _-G,_ _--get_ multiple times has no extra effect. Disable it again with --no-get. Examples: curl --get curl --get -d "tool=curl" -d "age=old" curl --get -I -d "tool=curl" See also _-d,_ _--data_ and _-X,_ _--request_. ### -g, --globoff This option switches off the "URL globbing parser". When you set this option, you can specify URLs that contain the letters {}[] without having curl itself interpret them. Note that these letters are not normal legal URL contents but they should be encoded according to the URI standard. Providing _-g,_ _--globoff_ multiple times has no extra effect. Disable it again with --no-globoff. Example: curl -g "{[]}}}}" See also _-K,_ _--config_ and _-q,_ _--disable_. ### --happy-eyeballs-timeout-ms Happy Eyeballs is an algorithm that attempts to connect to both IPv4 and IPv6 ad‐ dresses for dual-stack hosts, giving IPv6 a head-start of the specified number of mil‐ liseconds. If the IPv6 address cannot be connected to within that time, then a connec‐ tion attempt is made to the IPv4 address in parallel. The first connection to be es‐ tablished is the one that is used. The range of suggested useful values is limited. Happy Eyeballs RFC 6555 says "It is RECOMMENDED that connection attempts be paced 150-250 ms apart to balance human fac‐ tors against network load." libcurl currently defaults to 200 ms. Firefox and Chrome currently default to 300 ms. If _--happy-eyeballs-timeout-ms_ is provided several times, the last set value is used. Example: curl --happy-eyeballs-timeout-ms 500 See also _-m,_ _--max-time_ and _--connect-timeout_. Added in 7.59.0. ### --haproxy-clientip (HTTP) Sets a client IP in HAProxy PROXY protocol v1 header at the beginning of the connection. For valid requests, IPv4 addresses must be indicated as a series of exactly 4 integers in the range [0..255] inclusive written in decimal representation separated by exactly one dot between each other. Heading zeroes are not permitted in front of numbers in order to avoid any possible confusion with octal numbers. IPv6 addresses must be indi‐ cated as series of 4 hexadecimal digits (upper or lower case) delimited by colons be‐ tween each other, with the acceptance of one double colon sequence to replace the largest acceptable range of consecutive zeroes. The total number of decoded bits must exactly be 128. Otherwise, any string can be accepted for the client IP and get sent. It replaces _--haproxy-protocol_ if used, it is not necessary to specify both flags. This option is primarily useful when sending test requests to verify a service is working as intended. If _--haproxy-clientip_ is provided several times, the last set value is used. Example: curl --haproxy-clientip $IP See also _-x,_ _--proxy_. Added in 8.2.0. ### --haproxy-protocol (HTTP) Send a HAProxy PROXY protocol v1 header at the beginning of the connection. This is used by some load balancers and reverse proxies to indicate the client's true IP address and port. This option is primarily useful when sending test requests to a service that expects this header. Providing _--haproxy-protocol_ multiple times has no extra effect. Disable it again with --no-haproxy-protocol. Example: curl --haproxy-protocol See also _-x,_ _--proxy_. Added in 7.60.0. ### -I, --head (HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the command HEAD which this uses to get nothing but the header of a document. When used on an FTP or FILE file, curl displays the file size and last modification time only. Providing _-I,_ _--head_ multiple times has no extra effect. Disable it again with --no-head. Example: curl -I See also _-G,_ _--get_, _-v,_ _--verbose_ and _--trace-ascii_. ### -H, --header
(HTTP IMAP SMTP) Extra header to include in information sent. When used within an HTTP request, it is added to the regular request headers. For an IMAP or SMTP MIME uploaded mail built with _-F,_ _--form_ options, it is prepended to the resulting MIME document, effectively including it at the mail global level. It does not affect raw uploaded mails (Added in 7.56.0). You may specify any number of extra headers. Note that if you should add a custom header that has the same name as one of the internal ones curl would use, your exter‐ nally set header is used instead of the internal one. This allows you to make even trickier stuff than curl would normally do. You should not replace internally set headers without knowing perfectly well what you are doing. Remove an internal header by giving a replacement without content on the right side of the colon, as in: -H "Host:". If you send the custom header with no-value then its header must be termi‐ nated with a semicolon, such as -H "X-Custom-Header;" to send "X-Custom-Header:". curl makes sure that each header you add/replace is sent with the proper end-of-line marker, you should thus **not **add that as a part of the header content: do not add new‐ lines or carriage returns, they only mess things up for you. curl passes on the verba‐ tim string you give it without any filter or other safe guards. That includes white space and control characters. This option can take an argument in @filename style, which then adds a header for each line in the input file. Using @- makes curl read the header file from stdin. Added in 7.55.0. Please note that most anti-spam utilities check the presence and value of several MIME mail headers: these are "From:", "To:", "Date:" and "Subject:" among others and should be added with this option. You need _--proxy-header_ to send custom headers intended for an HTTP proxy. Added in 7.37.0. Passing on a "Transfer-Encoding: chunked" header when doing an HTTP request with a re‐ quest body, makes curl send the data using chunked encoding. **WARNING**: headers set with this option are set in all HTTP requests - even after redi‐ rects are followed, like when told with _-L,_ _--location_. This can lead to the header being sent to other hosts than the original host, so sensitive headers should be used with caution combined with following redirects. _-H,_ _--header_ can be used several times in a command line Examples: curl -H "X-First-Name: Joe" curl -H "User-Agent: yes-please/2000" curl -H "Host:" curl -H @headers.txt See also _-A,_ _--user-agent_ and _-e,_ _--referer_. ### -h, --help Usage help. This lists all curl command line options within the given **category**. If no argument is provided, curl displays only the most important command line argu‐ ments. For category **all**, curl displays help for all options. If **category **is specified, curl displays all available help categories. Example: curl --help all See also _-v,_ _--verbose_. ### --hostpubmd5 (SFTP SCP) Pass a string containing 32 hexadecimal digits. The string should be the 128 bit MD5 checksum of the remote host's public key, curl refuses the connection with the host unless the md5sums match. If _--hostpubmd5_ is provided several times, the last set value is used. Example: curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/ See also _--hostpubsha256_. ### --hostpubsha256 (SFTP SCP) Pass a string containing a Base64-encoded SHA256 hash of the remote host's public key. Curl refuses the connection with the host unless the hashes match. This feature requires libcurl to be built with libssh2 and does not work with other SSH backends. If _--hostpubsha256_ is provided several times, the last set value is used. Example: curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/ See also _--hostpubmd5_. Added in 7.80.0. ### --hsts (HTTPS) This option enables HSTS for the transfer. If the file name points to an ex‐ isting HSTS cache file, that is used. After a completed transfer, the cache is saved to the file name again if it has been modified. If curl is told to use HTTP:// for a transfer involving a host name that exists in the HSTS cache, it upgrades the transfer to use HTTPS. Each HSTS cache entry has an indi‐ vidual life time after which the upgrade is no longer performed. Specify a "" file name (zero length) to avoid loading/saving and make curl just handle HSTS in memory. If this option is used several times, curl loads contents from all the files but the last one is used for saving. _--hsts_ can be used several times in a command line Example: curl --hsts cache.txt See also _--proto_. Added in 7.74.0. --http0.9 (HTTP) Tells curl to be fine with HTTP version 0.9 response. HTTP/0.9 is a response without headers and therefore you can also connect with this to non-HTTP servers and still get a response since curl simply transparently downgrades - if allowed. HTTP/0.9 is disabled by default (added in 7.66.0) Providing _--http0.9_ multiple times has no extra effect. Disable it again with --no-http0.9. Example: curl --http0.9 See also _--http1.1_, _--http2_ and _--http3_. Added in 7.64.0. -0, --http1.0 (HTTP) Tells curl to use HTTP version 1.0 instead of using its internally preferred HTTP version. Providing _-0,_ _--http1.0_ multiple times has no extra effect. Example: curl --http1.0 See also _--http0.9_ and _--http1.1_. This option is mutually exclusive to _--http1.1_ and _--http2_ and _--http2-prior-knowledge_ and _--http3_. --http1.1 (HTTP) Tells curl to use HTTP version 1.1. Providing _--http1.1_ multiple times has no extra effect. Example: curl --http1.1 See also _-0,_ _--http1.0_ and _--http0.9_. This option is mutually exclusive to _-0,_ _--http1.0_ and _--http2_ and _--http2-prior-knowledge_ and _--http3_. ### --http2-prior-knowledge (HTTP) Tells curl to issue its non-TLS HTTP requests using HTTP/2 without HTTP/1.1 Up‐ grade. It requires prior knowledge that the server supports HTTP/2 straight away. HTTPS requests still do HTTP/2 the standard way with negotiated protocol version in the TLS handshake. Providing _--http2-prior-knowledge_ multiple times has no extra effect. Disable it again with --no-http2-prior-knowledge. Example: curl --http2-prior-knowledge See also _--http2_ and _--http3_. _--http2-prior-knowledge_ requires that the underlying libcurl was built to support HTTP/2. This option is mutually exclusive to _--http1.1_ and _-0,_ _--http1.0_ and _--http2_ and _--http3_. ### --http2 (HTTP) Tells curl to use HTTP version 2. For HTTPS, this means curl negotiates HTTP/2 in the TLS handshake. curl does this by default. For HTTP, this means curl attempts to upgrade the request to HTTP/2 using the Upgrade: request header. When curl uses HTTP/2 over HTTPS, it does not itself insist on TLS 1.2 or higher even though that is required by the specification. A user can add this version requirement with _--tlsv1.2_. Providing _--http2_ multiple times has no extra effect. Example: curl --http2 See also _--http1.1_, _--http3_ and _--no-alpn_. _--http2_ requires that the underlying libcurl was built to support HTTP/2. This option is mutually exclusive to _--http1.1_ and _-0,_ _--http1.0_ and _--http2-prior-knowledge_ and _--http3_. ### --http3-only (HTTP) **WARNING**: this option is experimental. Do not use in production. Instructs curl to use HTTP/3 to the host in the URL, with no fallback to earlier HTTP versions. HTTP/3 can only be used for HTTPS and not for HTTP URLs. For HTTP, this op‐ tion triggers an error. This option allows a user to avoid using the Alt-Svc method of upgrading to HTTP/3 when you know that the target speaks HTTP/3 on the given host and port. This option makes curl fail if a QUIC connection cannot be established, it does not attempt any other HTTP versions on its own. Use _--http3_ for similar functionality _with_ a fallback. Providing _--http3-only_ multiple times has no extra effect. Example: curl --http3-only See also _--http1.1_, _--http2_ and _--http3_. _--http3-only_ requires that the underlying libcurl was built to support HTTP/3. This option is mutually exclusive to _--http1.1_ and _-0,_ _--http1.0_ and _--http2_ and _--http2-prior-knowledge_ and _--http3_. Added in 7.88.0. ### --http3 (HTTP) **WARNING**: this option is experimental. Do not use in production. Tells curl to try HTTP/3 to the host in the URL, but fallback to earlier HTTP versions if the HTTP/3 connection establishment fails. HTTP/3 is only available for HTTPS and not for HTTP URLs. This option allows a user to avoid using the Alt-Svc method of upgrading to HTTP/3 when you know that the target speaks HTTP/3 on the given host and port. When asked to use HTTP/3, curl issues a separate attempt to use older HTTP versions with a slight delay, so if the HTTP/3 transfer fails or is slow, curl still tries to proceed with an older HTTP version. Use _--http3-only_ for similar functionality _without_ a fallback. Providing _--http3_ multiple times has no extra effect. Example: curl --http3 See also _--http1.1_ and _--http2_. _--http3_ requires that the underlying libcurl was built to support HTTP/3. This option is mutually exclusive to _--http1.1_ and _-0,_ _--http1.0_ and _--http2_ and _--http2-prior-knowledge_ and _--http3-only_. Added in 7.66.0. ### --ignore-content-length (FTP HTTP) For HTTP, Ignore the Content-Length header. This is particularly useful for servers running Apache 1.x, which reports incorrect Content-Length for files larger than 2 gigabytes. For FTP, this makes curl skip the SIZE command to figure out the size before download‐ ing a file. This option does not work for HTTP if libcurl was built to use hyper. Providing _--ignore-content-length_ multiple times has no extra effect. Disable it again with --no-ignore-content-length. Example: curl --ignore-content-length See also _--ftp-skip-pasv-ip_. ### -i, --include Include the HTTP response headers in the output. The HTTP response headers can include things like server name, cookies, date of the document, HTTP version and more... To view the request headers, consider the _-v,_ _--verbose_ option. Prior to 7.75.0 curl did not print the headers if _-f,_ _--fail_ was used in combination with this option and there was error reported by server. Providing _-i,_ _--include_ multiple times has no extra effect. Disable it again with --no-include. Example: curl -i See also _-v,_ _--verbose_. ### -k, --insecure (TLS SFTP SCP) By default, every secure connection curl makes is verified to be secure before the transfer takes place. This option makes curl skip the verification step and proceed without checking. When this option is not used for protocols using TLS, curl verifies the server's TLS certificate before it continues: that the certificate contains the right name which matches the host name used in the URL and that the certificate has been signed by a CA certificate present in the cert store. See this online resource for further details: For SFTP and SCP, this option makes curl skip the _known_hosts_ verification. _known_hosts_ is a file normally stored in the user's home directory in the ".ssh" sub‐ directory, which contains host names and their public keys. **WARNING**: using this option makes the transfer insecure. When curl uses secure protocols it trusts responses and allows for example HSTS and Alt-Svc information to be stored and used subsequently. Using _-k,_ _--insecure_ can make curl trust and use such information from malicious servers. Providing _-k,_ _--insecure_ multiple times has no extra effect. Disable it again with --no-insecure. Example: curl --insecure See also _--proxy-insecure_, _--cacert_ and _--capath_. ### --interface Perform an operation using a specified interface. You can enter interface name, IP ad‐ dress or host name. An example could look like: curl --interface eth0:1 On Linux it can be used to specify a **VRF**, but the binary needs to either have **CAP_NET_RAW **or to be run as root. More information about Linux **VRF**: ‐ nel.org/doc/Documentation/networking/vrf.txt If _--interface_ is provided several times, the last set value is used. Example: curl --interface eth0 See also _--dns-interface_. ### --ipfs-gateway Specify which gateway to use for IPFS and IPNS URLs. Not specifying this will instead make curl check if the IPFS_GATEWAY environment variable is set, or if a ~/.ipfs/gate‐ way file holding the gateway URL exists. If you run a local IPFS node, this gateway is by default available under ‐ host:8080. A full example URL would look like: curl --ipfs-gateway ipfs://bafybeigagd5nmnn2iys2f3doro7ydrevyr2mzarwidgadawmamiteydbzi There are many public IPFS gateways. See for example: WARNING: If you opt to go for a remote gateway you should be aware that you completely trust the gateway. This is fine in local gateways as you host it yourself. With remote gateways there could potentially be a malicious actor returning you data that does not match the request you made, inspect or even interfere with the request. You will not notice this when using curl. A mitigation could be to go for a "trustless" gateway. This means you locally verify that the data. Consult the docs page on trusted vs trustless: If _--ipfs-gateway_ is provided several times, the last set value is used. Example: curl --ipfs-gateway ipfs:// See also _-h,_ _--help_ and _-M,_ _--manual_. Added in 8.4.0. -4, --ipv4 This option tells curl to use IPv4 addresses only when resolving host names, and not for example try IPv6. Providing _-4,_ _--ipv4_ multiple times has no extra effect. Example: curl --ipv4 See also _--http1.1_ and _--http2_. This option is mutually exclusive to _-6,_ _--ipv6_. -6, --ipv6 This option tells curl to use IPv6 addresses only when resolving host names, and not for example try IPv4. Providing _-6,_ _--ipv6_ multiple times has no extra effect. Example: curl --ipv6 See also _--http1.1_ and _--http2_. This option is mutually exclusive to _-4,_ _--ipv4_. ### --json (HTTP) Sends the specified JSON data in a POST request to the HTTP server. _--json_ works as a shortcut for passing on these three options: --data [arg] --header "Content-Type: application/json" --header "Accept: application/json" There is no verification that the passed in data is actual JSON or that the syntax is correct. If you start the data with the letter @, the rest should be a file name to read the data from, or a single dash (-) if you want curl to read the data from stdin. Posting data from a file named 'foobar' would thus be done with _--json_ @foobar and to instead read the data from stdin, use _--json_ @-. If this option is used more than once on the same command line, the additional data pieces are concatenated to the previous before sending. The headers this option sets can be overridden with _-H,_ _--header_ as usual. _--json_ can be used several times in a command line Examples: curl --json '{ "drink": "coffe" }' curl --json '{ "drink":' --json ' "coffe" }' curl --json @prepared curl --json @- < json.txt See also _--data-binary_ and _--data-raw_. This option is mutually exclusive to _-F,_ _--form_ and _-I,_ _--head_ and _-T,_ _--upload-file_. Added in 7.82.0. ### -j, --junk-session-cookies (HTTP) When curl is told to read cookies from a given file, this option makes it dis‐ card all "session cookies". This has the same effect as if a new session is started. Typical browsers discard session cookies when they are closed down. Providing _-j,_ _--junk-session-cookies_ multiple times has no extra effect. Disable it again with --no-junk-session-cookies. Example: curl --junk-session-cookies -b cookies.txt See also _-b,_ _--cookie_ and _-c,_ _--cookie-jar_. ### --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). Keepalives are used by the TCP stack to detect broken networks on idle connections. The number of missed keepalive probes before de‐ claring the connection down is OS dependent and is commonly 9 or 10. This option has no effect if _--no-keepalive_ is used. If unspecified, the option defaults to 60 seconds. If _--keepalive-time_ is provided several times, the last set value is used. Example: curl --keepalive-time 20 See also _--no-keepalive_ and _-m,_ _--max-time_. ### --key-type (TLS) Private key file type. Specify which type your _--key_ provided private key is. DER, PEM, and ENG are supported. If not specified, PEM is assumed. If _--key-type_ is provided several times, the last set value is used. Example: curl --key-type DER --key here See also _--key_. ### --key (TLS SSH) Private key file name. Allows you to provide your private key in this sepa‐ rate file. For SSH, if not specified, curl tries the following candidates in order: '~/.ssh/id_rsa', '~/.ssh/id_dsa', './id_rsa', './id_dsa'. If curl is built against OpenSSL library, and the engine pkcs11 is available, then a PKCS#11 URI (RFC 7512) can be used to specify a private key located in a PKCS#11 de‐ vice. A string beginning with "pkcs11:" is interpreted as a PKCS#11 URI. If a PKCS#11 URI is provided, then the _--engine_ option is set as "pkcs11" if none was provided and the _--key-type_ option is set as "ENG" if none was provided. If curl is built against Secure Transport or Schannel then this option is ignored for TLS protocols (HTTPS, etc). Those backends expect the private key to be already present in the keychain or PKCS#12 file containing the certificate. If _--key_ is provided several times, the last set value is used. Example: curl --cert certificate --key here See also _--key-type_ and _-E,_ _--cert_. ### --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' is used. If _--krb_ is provided several times, the last set value is used. Example: curl --krb clear ftp://example.com/ See also _--delegation_ and _--ssl_. _--krb_ requires that the underlying libcurl was built to support Kerberos. ### --libcurl Append this option to any ordinary curl command line, and you get libcurl-using C source code written to the file that does the equivalent of what your command-line op‐ eration does! This option is global and does not need to be specified for each use of --next. If _--libcurl_ is provided several times, the last set value is used. Example: curl --libcurl client.c See also _-v,_ _--verbose_. ### --limit-rate Specify the maximum transfer rate you want curl to use - for both downloads and up‐ loads. This feature is useful if you have a limited pipe and you would like your transfer not to use your entire bandwidth. To make it slower than it otherwise would be. The given speed is measured in bytes/second, unless a suffix is appended. Appending 'k' or 'K' counts the number as kilobytes, 'm' or 'M' makes it megabytes, while 'g' or 'G' makes it gigabytes. The suffixes (k, M, G, T, P) are 1024 based. For example 1k is 1024. Examples: 200K, 3m and 1G. The rate limiting logic works on averaging the transfer speed to no more than the set threshold over a period of multiple seconds. If you also use the _-Y,_ _--speed-limit_ option, that option takes precedence and might cripple the rate-limiting slightly, to help keeping the speed-limit logic working. If _--limit-rate_ is provided several times, the last set value is used. Examples: curl --limit-rate 100K curl --limit-rate 1000 curl --limit-rate 10M See also _--rate_, _-Y,_ _--speed-limit_ and _-y,_ _--speed-time_. ### -l, --list-only (FTP POP3 SFTP) (FTP) When listing an FTP directory, this switch forces a name-only view. This is especially useful if the user wants to machine-parse the contents of an FTP directory since the normal directory view does not use a standard look or format. When used like this, the option causes an NLST command to be sent to the server in‐ stead of LIST. Note: Some FTP servers list only files in their response to NLST; they do not include sub-directories and symbolic links. (SFTP) When listing an SFTP directory, this switch forces a name-only view, one per line. This is especially useful if the user wants to machine-parse the contents of an SFTP directory since the normal directory view provides more information than just file names. (POP3) When retrieving a specific email from POP3, this switch forces a LIST command to be performed instead of RETR. This is particularly useful if the user wants to see if a specific message-id exists on the server and what size it is. Note: When combined with _-X,_ _--request_, this option can be used to send a UIDL command instead, so the user may use the email's unique identifier rather than its message-id to make the request. Providing _-l,_ _--list-only_ multiple times has no extra effect. Disable it again with --no-list-only. Example: curl --list-only ftp://example.com/dir/ See also _-Q,_ _--quote_ and _-X,_ _--request_. ### --local-port Set a preferred single number or range (FROM-TO) of local port numbers to use for the connection(s). Note that port numbers by nature are a scarce resource so setting this range to something too narrow might cause unnecessary connection setup failures. If _--local-port_ is provided several times, the last set value is used. Example: curl --local-port 1000-3000 See also _-g,_ _--globoff_. ### --location-trusted (HTTP) Like _-L,_ _--location_, but allows sending the name + password to all hosts that the site may redirect to. This may or may not introduce a security breach if the site redirects you to a site to which you send your authentication info (which is plaintext in the case of HTTP Basic authentication). Providing _--location-trusted_ multiple times has no extra effect. Disable it again with --no-location-trusted. Example: curl --location-trusted -u user:password See also _-u,_ _--user_. ### -L, --location (HTTP) If the server reports that the requested page has moved to a different location (indicated with a Location: header and a 3XX response code), this option makes curl redo the request on the new place. If used together with _-i,_ _--include_ or _-I,_ _--head_, headers from all requested pages are shown. When authentication is used, curl only sends its credentials to the initial host. If a redirect takes curl to a different host, it does not get the user+password pass on. See also _--location-trusted_ on how to change this. Limit the amount of redirects to follow by using the _--max-redirs_ option. When curl follows a redirect and if the request is a POST, it sends the following re‐ quest with a GET if the HTTP response was 301, 302, or 303. If the response code was any other 3xx code, curl resends the following request using the same unmodified method. You can tell curl to not change POST requests to GET after a 30x response by using the dedicated options for that: _--post301_, _--post302_ and _--post303_. The method set with _-X,_ _--request_ overrides the method curl would otherwise select to use. Providing _-L,_ _--location_ multiple times has no extra effect. Disable it again with --no-location. Example: curl -L See also _--resolve_ and _--alt-svc_. ### --login-options (IMAP LDAP POP3 SMTP) Specify the login options to use during server authentication. You can use login options to specify protocol specific options that may be used during authentication. At present only IMAP, POP3 and SMTP support login options. For more information about login options please see RFC 2384, RFC 5092 and the IETF draft . Since 8.2.0, IMAP supports the login option "AUTH=+LOGIN". With this option, curl uses the plain (not SASL) LOGIN IMAP command even if the server advertises SASL authentica‐ tion. Care should be taken in using this option, as it sends your password over the network in plain text. This does not work if the IMAP server disables the plain LOGIN (e.g. to prevent password snooping). If _--login-options_ is provided several times, the last set value is used. Example: curl --login-options 'AUTH=*' imap://example.com See also _-u,_ _--user_. ### --mail-auth
(SMTP) Specify a single address. This is used to specify the authentication address (identity) of a submitted message that is being relayed to another server. If _--mail-auth_ is provided several times, the last set value is used. Example: curl --mail-auth -T mail smtp://example.com/ See also _--mail-rcpt_ and _--mail-from_. ### --mail-from
(SMTP) Specify a single address that the given mail should get sent from. If _--mail-from_ is provided several times, the last set value is used. Example: curl --mail-from -T mail smtp://example.com/ See also _--mail-rcpt_ and _--mail-auth_. ### --mail-rcpt-allowfails (SMTP) When sending data to multiple recipients, by default curl aborts SMTP conversa‐ tion if at least one of the recipients causes RCPT TO command to return an error. The default behavior can be changed by passing _--mail-rcpt-allowfails_ command-line op‐ tion which makes curl ignore errors and proceed with the remaining valid recipients. If all recipients trigger RCPT TO failures and this flag is specified, curl still aborts the SMTP conversation and returns the error received from to the last RCPT TO command. Providing _--mail-rcpt-allowfails_ multiple times has no extra effect. Disable it again with --no-mail-rcpt-allowfails. Example: curl --mail-rcpt-allowfails --mail-rcpt smtp://example.com See also _--mail-rcpt_. Added in 7.69.0. ### --mail-rcpt
(SMTP) Specify a single email address, user name or mailing list name. Repeat this op‐ tion several times to send to multiple recipients. When performing an address verification (**VRFY **command), the recipient should be speci‐ fied as the user name or user name and domain (as per Section 3.5 of RFC 5321). When performing a mailing list expand (EXPN command), the recipient should be speci‐ fied using the mailing list name, such as "Friends" or "London-Office". _--mail-rcpt_ can be used several times in a command line Example: curl --mail-rcpt smtp://example.com See also _--mail-rcpt-allowfails_. ### -M, --manual Manual. Display the huge help text. Example: curl --manual See also _-v,_ _--verbose_, _--libcurl_ and _--trace_. ### --max-filesize (FTP HTTP MQTT) Specify the maximum size (in bytes) of a file to download. If the file requested is larger than this value, the transfer does not start and curl returns with exit code 63. A size modifier may be used. For example, Appending 'k' or 'K' counts the number as kilobytes, 'm' or 'M' makes it megabytes, while 'g' or 'G' makes it gigabytes. Exam‐ ples: 200K, 3m and 1G. (Added in 7.58.0) **NOTE**: before curl 8.4.0, when the file size is not known prior to download, for such files this option has no effect even if the file transfer ends up being larger than this given limit. Starting with curl 8.4.0, this option aborts the transfer if it reaches the threshold during transfer. If _--max-filesize_ is provided several times, the last set value is used. Example: curl --max-filesize 100K See also _--limit-rate_. ### --max-redirs (HTTP) Set maximum number of redirections to follow. When _-L,_ _--location_ is used, to prevent curl from following too many redirects, by default, the limit is set to 50 redirects. Set this option to -1 to make it unlimited. If _--max-redirs_ is provided several times, the last set value is used. Example: curl --max-redirs 3 --location See also _-L,_ _--location_. ### -m, --max-time Maximum time in seconds that you allow each transfer to take. This is useful for pre‐ venting your batch jobs from hanging for hours due to slow networks or links going down. This option accepts decimal values. If you enable retrying the transfer (_--retry_) then the maximum time counter is reset each time the transfer is retried. You can use _--retry-max-time_ to limit the retry time. The decimal value needs to provided using a dot (.) as decimal separator - not the lo‐ cal version even if it might be using another separator. If _-m,_ _--max-time_ is provided several times, the last set value is used. Examples: curl --max-time 10 curl --max-time 2.92 See also _--connect-timeout_ and _--retry-max-time_. ### --metalink This option was previously used to specify a Metalink resource. Metalink support is disabled in curl for security reasons (added in 7.78.0). If _--metalink_ is provided several times, the last set value is used. Example: curl --metalink file See also _-Z,_ _--parallel_. ### --negotiate (HTTP) Enables Negotiate (SPNEGO) authentication. This option requires a library built with GSS-API or SSPI support. Use _-V,_ _--version_ to see if your curl supports GSS-API/SSPI or SPNEGO. When using this option, you must also provide a fake _-u,_ _--user_ option to activate the authentication code properly. Sending a '-u :' is enough as the user name and password from the _-u,_ _--user_ option are not actually used. Providing _--negotiate_ multiple times has no extra effect. Example: curl --negotiate -u : See also _--basic_, _--ntlm_, _--anyauth_ and _--proxy-negotiate_. ### --netrc-file This option is similar to _-n,_ _--netrc_, except that you provide the path (absolute or relative) to the netrc file that curl should use. You can only specify one netrc file per invocation. It abides by _--netrc-optional_ if specified. If _--netrc-file_ is provided several times, the last set value is used. Example: curl --netrc-file netrc See also _-n,_ _--netrc_, _-u,_ _--user_ and _-K,_ _--config_. This option is mutually exclusive to _-n,_ _--netrc_. ### --netrc-optional Similar to _-n,_ _--netrc_, but this option makes the .netrc usage **optional **and not manda‐ tory as the _-n,_ _--netrc_ option does. Providing _--netrc-optional_ multiple times has no extra effect. Disable it again with --no-netrc-optional. Example: curl --netrc-optional See also _--netrc-file_. This option is mutually exclusive to _-n,_ _--netrc_. ### -n, --netrc Makes curl scan the _.netrc_ file in the user's home directory for login name and pass‐ word. This is typically used for FTP on Unix. If used with HTTP, curl enables user au‐ thentication. See [_netrc(5)](https://www.chedong.com/phpMan.php/man/netrc/5/markdown)_ and [_ftp(1)](https://www.chedong.com/phpMan.php/man/ftp/1/markdown)_ for details on the file format. Curl does not complain if that file does not have the right permissions (it should be neither world- nor group-readable). The environment variable "HOME" is used to find the home direc‐ tory. On Windows two filenames in the home directory are checked: _.netrc_ and __netrc_, prefer‐ ring the former. Older versions on Windows checked for __netrc_ only. A quick and simple example of how to setup a _.netrc_ to allow curl to FTP to the ma‐ chine host.domain.com with user name 'myself' and password 'secret' could look similar to: machine host.domain.com login myself password secret Providing _-n,_ _--netrc_ multiple times has no extra effect. Disable it again with --no-netrc. Example: curl --netrc See also _--netrc-file_, _-K,_ _--config_ and _-u,_ _--user_. This option is mutually exclusive to _--netrc-file_ and _--netrc-optional_. -:, --next Tells curl to use a separate operation for the following URL and associated options. This allows you to send several URL requests, each with their own specific options, for example, such as different user names or custom requests for each. _-:,_ _--next_ resets all local options and only global ones have their values survive over to the operation following the _-:,_ _--next_ instruction. Global options include _-v,_ _--verbose_, _--trace_, _--trace-ascii_ and _--fail-early_. For example, you can do both a GET and a POST in a single command line: curl www1.example.com --next -d postthis www2.example.com _-:,_ _--next_ can be used several times in a command line Examples: curl --next -d postthis www2.example.com curl -I --next See also _-Z,_ _--parallel_ and _-K,_ _--config_. ### --no-alpn (HTTPS) Disable the ALPN TLS extension. ALPN is enabled by default if libcurl was built with an SSL library that supports ALPN. ALPN is used by a libcurl that supports HTTP/2 to negotiate HTTP/2 support with the server during https sessions. Note that this is the negated option name documented. You can use --alpn to enable ALPN. Providing _--no-alpn_ multiple times has no extra effect. Disable it again with --alpn. Example: curl --no-alpn See also _--no-npn_ and _--http2_. _--no-alpn_ requires that the underlying libcurl was built to support TLS. ### -N, --no-buffer Disables the buffering of the output stream. In normal work situations, curl uses a standard buffered output stream that has the effect that it outputs the data in chunks, not necessarily exactly when the data arrives. Using this option disables that buffering. Note that this is the negated option name documented. You can use --buffer to enable buffering again. Providing _-N,_ _--no-buffer_ multiple times has no extra effect. Disable it again with --buffer. Example: curl --no-buffer See also _-#,_ _--progress-bar_. ### --no-clobber When used in conjunction with the _-o,_ _--output_, _-J,_ _--remote-header-name_, _-O,_ _--re‐_ _mote-name_, or _--remote-name-all_ options, curl avoids overwriting files that already exist. Instead, a dot and a number gets appended to the name of the file that would be created, up to filename.100 after which it does not create any file. Note that this is the negated option name documented. You can thus use --clobber to enforce the clobbering, even if _-J,_ _--remote-header-name_ is specified. Providing _--no-clobber_ multiple times has no extra effect. Disable it again with --clobber. Example: curl --no-clobber --output local/dir/file See also _-o,_ _--output_ and _-O,_ _--remote-name_. Added in 7.83.0. ### --no-keepalive Disables the use of keepalive messages on the TCP connection. curl otherwise enables them by default. Note that this is the negated option name documented. You can thus use --keepalive to enforce keepalive. Providing _--no-keepalive_ multiple times has no extra effect. Disable it again with --keepalive. Example: curl --no-keepalive See also _--keepalive-time_. ### --no-npn (HTTPS) curl never uses NPN, this option has no effect (added in 7.86.0). Disable the NPN TLS extension. NPN is enabled by default if libcurl was built with an SSL library that supports NPN. NPN is used by a libcurl that supports HTTP/2 to nego‐ tiate HTTP/2 support with the server during https sessions. Providing _--no-npn_ multiple times has no extra effect. Disable it again with --npn. Example: curl --no-npn See also _--no-alpn_ and _--http2_. _--no-npn_ requires that the underlying libcurl was built to support TLS. ### --no-progress-meter Option to switch off the progress meter output without muting or otherwise affecting warning and informational messages like _-s,_ _--silent_ does. Note that this is the negated option name documented. You can thus use --progress-me‐ ter to enable the progress meter again. Providing _--no-progress-meter_ multiple times has no extra effect. Disable it again with --progress-meter. Example: curl --no-progress-meter -o store See also _-v,_ _--verbose_ and _-s,_ _--silent_. Added in 7.67.0. ### --no-sessionid (TLS) Disable curl's use of SSL session-ID caching. By default all transfers are done using the cache. Note that while nothing should ever get hurt by attempting to reuse SSL session-IDs, there seem to be broken SSL implementations in the wild that may re‐ quire you to disable this in order for you to succeed. Note that this is the negated option name documented. You can thus use --sessionid to enforce session-ID caching. Providing _--no-sessionid_ multiple times has no extra effect. Disable it again with --sessionid. Example: curl --no-sessionid See also _-k,_ _--insecure_. ### --noproxy Comma-separated list of hosts for which not to use a proxy, if one is specified. The only wildcard is a single * character, which matches all hosts, and effectively dis‐ ables the proxy. Each name in this list is matched as either a domain which contains the hostname, or the hostname itself. For example, local.com would match local.com, local.com:80, and www.local.com, but not www.notlocal.com. This option overrides the environment variables that disable the proxy ('no_proxy' and 'NO_PROXY') (added in 7.53.0). If there is an environment variable disabling a proxy, you can set the no proxy list to "" to override it. IP addresses specified to this option can be provided using CIDR notation (added in 7.86.0): an appended slash and number specifies the number of "network bits" out of the address to use in the comparison. For example "192.168.0.0/16" would match all ad‐ dresses starting with "192.168". If _--noproxy_ is provided several times, the last set value is used. Example: curl --noproxy "www.example" See also _-x,_ _--proxy_. ### --ntlm-wb (HTTP) Enables NTLM much in the style _--ntlm_ does, but hand over the authentication to the separate binary ntlmauth application that is executed when needed. Providing _--ntlm-wb_ multiple times has no extra effect. Example: curl --ntlm-wb -u user:password See also _--ntlm_ and _--proxy-ntlm_. --ntlm (HTTP) Enables NTLM authentication. The NTLM authentication method was designed by Mi‐ crosoft and is used by IIS web servers. It is a proprietary protocol, reverse-engi‐ neered 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_. Providing _--ntlm_ multiple times has no extra effect. Example: curl --ntlm -u user:password See also _--proxy-ntlm_. _--ntlm_ requires that the underlying libcurl was built to sup‐ port TLS. This option is mutually exclusive to _--basic_ and _--negotiate_ and _--digest_ and _--anyauth_. ### --oauth2-bearer (IMAP LDAP POP3 SMTP HTTP) Specify the Bearer Token for OAUTH 2.0 server authentica‐ tion. The Bearer Token is used in conjunction with the user name which can be speci‐ fied as part of the _--url_ or _-u,_ _--user_ options. The Bearer Token and user name are formatted according to RFC 6750. If _--oauth2-bearer_ is provided several times, the last set value is used. Example: curl --oauth2-bearer "mF_9.B5f-4.1JqM" See also _--basic_, _--ntlm_ and _--digest_. ### --output-dir This option specifies the directory in which files should be stored, when _-O,_ _--re‐_ _mote-name_ or _-o,_ _--output_ are used. The given output directory is used for all URLs and output options on the command line, up until the first _-:,_ _--next_. If the specified target directory does not exist, the operation fails unless _--cre‐_ _ate-dirs_ is also used. If _--output-dir_ is provided several times, the last set value is used. Example: curl --output-dir "tmp" -O See also _-O,_ _--remote-name_ and _-J,_ _--remote-header-name_. Added in 7.73.0. ### -o, --output Write output to instead of stdout. If you are using {} or [] to fetch multiple documents, you should quote the URL and you can use '#' followed by a number in the specifier. That variable is replaced with the current string for the URL being fetched. Like in: curl "http://{one,two}.example.com" -o "file_#1.txt" or use several variables like: curl "http://{site,host}.host[1-5].example" -o "#1_#2" You may use this option as many times as the number of URLs you have. For example, if you specify two URLs on the same command line, you can use it like this: curl -o aa example.com -o bb example.net and the order of the -o options and the URLs does not matter, just that the first -o is for the first URL and so on, so the above command line can also be written as curl example.com example.net -o aa -o bb See also the _--create-dirs_ option to create the local directories dynamically. Speci‐ fying the output as '-' (a single dash) passes the output to stdout. To suppress response bodies, you can redirect output to /dev/null: curl example.com -o /dev/null Or for Windows: curl example.com -o nul _-o,_ _--output_ can be used several times in a command line Examples: curl -o file curl "http://{one,two}.example.com" -o "file_#1.txt" curl "http://{site,host}.host[1-5].example" -o "#1_#2" curl -o file -o file2 See also _-O,_ _--remote-name_, _--remote-name-all_ and _-J,_ _--remote-header-name_. ### --parallel-immediate When doing parallel transfers, this option instructs curl that it should rather prefer opening up more connections in parallel at once rather than waiting to see if new transfers can be added as multiplexed streams on another connection. This option is global and does not need to be specified for each use of --next. Providing _--parallel-immediate_ multiple times has no extra effect. Disable it again with --no-parallel-immediate. Example: curl --parallel-immediate -Z -o file1 -o file2 See also _-Z,_ _--parallel_ and _--parallel-max_. Added in 7.68.0. ### --parallel-max When asked to do parallel transfers, using _-Z,_ _--parallel_, this option controls the maximum amount of transfers to do simultaneously. This option is global and does not need to be specified for each use of _-:,_ _--next_. The default is 50. If _--parallel-max_ is provided several times, the last set value is used. Example: curl --parallel-max 100 -Z ftp://example.com/ See also _-Z,_ _--parallel_. Added in 7.66.0. ### -Z, --parallel Makes curl perform its transfers in parallel as compared to the regular serial manner. This option is global and does not need to be specified for each use of --next. Providing _-Z,_ _--parallel_ multiple times has no extra effect. Disable it again with --no-parallel. Example: curl --parallel -o file1 -o file2 See also _-:,_ _--next_ and _-v,_ _--verbose_. Added in 7.66.0. ### --pass (SSH TLS) Passphrase for the private key. If _--pass_ is provided several times, the last set value is used. Example: curl --pass secret --key file See also _--key_ and _-u,_ _--user_. ### --path-as-is Tell curl to not handle sequences of /../ or /./ in the given URL path. Normally curl squashes or merges them according to standards but with this option set you tell it not to do that. Providing _--path-as-is_ multiple times has no extra effect. Disable it again with --no-path-as-is. Example: curl --path-as-is See also _--request-target_. ### --pinnedpubkey (TLS) Tells curl to use the specified public key file (or hashes) to verify the peer. This can be a path to a file which contains a single public key in PEM or DER format, or any number of base64 encoded sha256 hashes preceded by 'sha256//' and separated by ';'. When negotiating a TLS or SSL connection, the server sends a certificate indicating its identity. A public key is extracted from this certificate and if it does not ex‐ actly match the public key provided to this option, curl aborts the connection before sending or receiving any data. This option is independent of option _-k,_ _--insecure_. If you use both options together then the peer is still verified by public key. PEM/DER support: OpenSSL and GnuTLS, wolfSSL (added in 7.43.0), mbedTLS , Secure Transport macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1) sha256 support: OpenSSL, GnuTLS and wolfSSL, mbedTLS (added in 7.47.0), Secure Transport macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1) Other SSL backends not supported. If _--pinnedpubkey_ is provided several times, the last set value is used. Examples: curl --pinnedpubkey keyfile curl --pinnedpubkey 'sha256//ce118b51897f4452dc' See also _--hostpubsha256_. ### --post301 (HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST requests into GET re‐ quests when following a 301 redirection. The non-RFC behavior is ubiquitous in web browsers, so curl does the conversion by default to maintain consistency. However, a server may require a POST to remain a POST after such a redirection. This option is meaningful only when using _-L,_ _--location_. Providing _--post301_ multiple times has no extra effect. Disable it again with --no-post301. Example: curl --post301 --location -d "data" See also _--post302_, _--post303_ and _-L,_ _--location_. ### --post302 (HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST requests into GET re‐ quests when following a 302 redirection. The non-RFC behavior is ubiquitous in web browsers, so curl does the conversion by default to maintain consistency. However, a server may require a POST to remain a POST after such a redirection. This option is meaningful only when using _-L,_ _--location_. Providing _--post302_ multiple times has no extra effect. Disable it again with --no-post302. Example: curl --post302 --location -d "data" See also _--post301_, _--post303_ and _-L,_ _--location_. ### --post303 (HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST requests into GET re‐ quests when following 303 redirections. A server may require a POST to remain a POST after a 303 redirection. This option is meaningful only when using _-L,_ _--location_. Providing _--post303_ multiple times has no extra effect. Disable it again with --no-post303. Example: curl --post303 --location -d "data" See also _--post302_, _--post301_ and _-L,_ _--location_. --preproxy [protocol://]host[:port] Use the specified SOCKS proxy before connecting to an HTTP or HTTPS _-x,_ _--proxy_. In such a case curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. Hence pre proxy. The pre proxy string should be specified with a protocol:// prefix to specify alterna‐ tive proxy protocols. Use socks4://, socks4a://, socks5:// or socks5h:// to request the specific SOCKS version to be used. No protocol specified makes curl default to SOCKS4. If the port number is not specified in the proxy string, it is assumed to be 1080. User and password that might be provided in the proxy string are URL decoded by curl. This allows you to pass in special characters such as @ by using %40 or pass in a colon with %3a. If _--preproxy_ is provided several times, the last set value is used. Example: curl --preproxy socks5://proxy.example -x See also _-x,_ _--proxy_ and _--socks5_. Added in 7.52.0. -#, --progress-bar Make curl display transfer progress as a simple progress bar instead of the standard, more informational, meter. This progress bar draws a single line of '#' characters across the screen and shows a percentage if the transfer size is known. For transfers without a known size, there is a space ship (-=o=-) that moves back and forth but only while data is being trans‐ ferred, with a set of flying hash sign symbols on top. This option is global and does not need to be specified for each use of --next. Providing _-#,_ _--progress-bar_ multiple times has no extra effect. Disable it again with --no-progress-bar. Example: curl -# -O See also _--styled-output_. ### --proto-default Tells curl to use _protocol_ for any URL missing a scheme name. An unknown or unsupported protocol causes error _CURLE_UNSUPPORTED_PROTOCOL_ (1). This option does not change the default proxy protocol (http). Without this option set, curl guesses protocol based on the host name, see _--url_ for details. If _--proto-default_ is provided several times, the last set value is used. Example: curl --proto-default https ftp.example.com See also _--proto_ and _--proto-redir_. ### --proto-redir Tells curl to limit what protocols it may use on redirect. Protocols denied by _--proto_ are not overridden by this option. See _--proto_ for how protocols are represented. Example, allow only HTTP and HTTPS on redirect: curl --proto-redir -all,http,https By default curl only allows HTTP, HTTPS, FTP and FTPS on redirects (added in 7.65.2). Specifying _all_ or _+all_ enables all protocols on redirects, which is not good for secu‐ rity. If _--proto-redir_ is provided several times, the last set value is used. Example: curl --proto-redir =http,https See also _--proto_. ### --proto Tells curl to limit what protocols it may use for transfers. Protocols are evaluated left to right, are comma separated, and are each a protocol name or 'all', optionally prefixed by zero or more modifiers. Available modifiers are: **+ **Permit this protocol in addition to protocols already permitted (this is the de‐ fault if no modifier is used). **- **Deny this protocol, removing it from the list of protocols already permitted. **= **Permit only this protocol (ignoring the list already permitted), though subject to later modification by subsequent entries in the comma separated list. For example: _--proto_ **-ftps **uses the default protocols, but disables ftps _--proto_ **-all,https,+http** only enables http and https _--proto_ **=http,https** also only enables http and https Unknown and disabled protocols produce a warning. This allows scripts to safely rely on being able to disable potentially dangerous 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 con‐ catenating the protocols into one instance of the option. If _--proto_ is provided several times, the last set value is used. Example: curl --proto =http,https,sftp See also _--proto-redir_ and _--proto-default_. ### --proxy-anyauth Tells curl to pick a suitable authentication method when communicating with the given HTTP proxy. This might cause an extra request/response round-trip. Providing _--proxy-anyauth_ multiple times has no extra effect. Example: curl --proxy-anyauth --proxy-user user:passwd -x proxy See also _-x,_ _--proxy_, _--proxy-basic_ and _--proxy-digest_. ### --proxy-basic Tells curl to use HTTP Basic authentication when communicating with the given proxy. Use _--basic_ for enabling HTTP Basic with a remote host. Basic is the default authenti‐ cation method curl uses with proxies. Providing _--proxy-basic_ multiple times has no extra effect. Example: curl --proxy-basic --proxy-user user:passwd -x proxy See also _-x,_ _--proxy_, _--proxy-anyauth_ and _--proxy-digest_. ### --proxy-ca-native (TLS) Tells curl to use the CA store from the native operating system to verify the HTTPS proxy. By default, curl uses a CA store provided in a single file or directory, but when using this option it interfaces the operating system's own vault. This option only works for curl on Windows when built to use OpenSSL. When curl on Windows is built to use Schannel, this feature is implied and curl then only uses the native CA store. curl built with wolfSSL also supports this option (added in 8.3.0). Providing _--proxy-ca-native_ multiple times has no extra effect. Disable it again with --no-proxy-ca-native. Example: curl --ca-native See also _--cacert_, _--capath_ and _-k,_ _--insecure_. Added in 8.2.0. ### --proxy-cacert Same as _--cacert_ but used in HTTPS proxy context. If _--proxy-cacert_ is provided several times, the last set value is used. Example: curl --proxy-cacert CA-file.txt -x See also _--proxy-capath_, _--cacert_, _--capath_ and _-x,_ _--proxy_. Added in 7.52.0. ### --proxy-capath Same as _--capath_ but used in HTTPS proxy context. If _--proxy-capath_ is provided several times, the last set value is used. Example: curl --proxy-capath /local/directory -x See also _--proxy-cacert_, _-x,_ _--proxy_ and _--capath_. Added in 7.52.0. ### --proxy-cert-type Same as _--cert-type_ but used in HTTPS proxy context. If _--proxy-cert-type_ is provided several times, the last set value is used. Example: curl --proxy-cert-type PEM --proxy-cert file -x See also _--proxy-cert_. Added in 7.52.0. --proxy-cert Same as _-E,_ _--cert_ but used in HTTPS proxy context. If _--proxy-cert_ is provided several times, the last set value is used. Example: curl --proxy-cert file -x See also _--proxy-cert-type_. Added in 7.52.0. ### --proxy-ciphers Same as _--ciphers_ but used in HTTPS proxy context. Specifies which ciphers to use in the connection to the HTTPS proxy. The list of ci‐ phers must specify valid ciphers. Read up on SSL cipher list details on this URL: If _--proxy-ciphers_ is provided several times, the last set value is used. Example: curl --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x See also _--ciphers_, _--curves_ and _-x,_ _--proxy_. Added in 7.52.0. ### --proxy-crlfile Same as _--crlfile_ but used in HTTPS proxy context. If _--proxy-crlfile_ is provided several times, the last set value is used. Example: curl --proxy-crlfile rejects.txt -x See also _--crlfile_ and _-x,_ _--proxy_. Added in 7.52.0. ### --proxy-digest Tells curl to use HTTP Digest authentication when communicating with the given proxy. Use _--digest_ for enabling HTTP Digest with a remote host. Providing _--proxy-digest_ multiple times has no extra effect. Example: curl --proxy-digest --proxy-user user:passwd -x proxy See also _-x,_ _--proxy_, _--proxy-anyauth_ and _--proxy-basic_. ### --proxy-header
(HTTP) Extra header to include in the request when sending HTTP to a proxy. You may specify any number of extra headers. This is the equivalent option to _-H,_ _--header_ but is for proxy communication only like in CONNECT requests when you want a separate header sent to the proxy to what is sent to the actual remote host. curl makes sure that each header you add/replace is sent with the proper end-of-line marker, you should thus **not **add that as a part of the header content: do not add new‐ lines or carriage returns, they only mess things up for you. Headers specified with this option are not included in requests that curl knows are not be sent to a proxy. This option can take an argument in @filename style, which then adds a header for each line in the input file (added in 7.55.0). Using @- makes curl read the headers from stdin. This option can be used multiple times to add/replace/remove multiple headers. _--proxy-header_ can be used several times in a command line Examples: curl --proxy-header "X-First-Name: Joe" -x curl --proxy-header "User-Agent: surprise" -x curl --proxy-header "Host:" -x See also _-x,_ _--proxy_. ### --proxy-http2 (HTTP) Tells curl to try negotiate HTTP version 2 with an HTTPS proxy. The proxy might still only offer HTTP/1 and then curl sticks to using that version. This has no effect for any other kinds of proxies. Providing _--proxy-http2_ multiple times has no extra effect. Disable it again with --no-proxy-http2. Example: curl --proxy-http2 -x proxy See also _-x,_ _--proxy_. _--proxy-http2_ requires that the underlying libcurl was built to support HTTP/2. Added in 8.1.0. ### --proxy-insecure Same as _-k,_ _--insecure_ but used in HTTPS proxy context. Providing _--proxy-insecure_ multiple times has no extra effect. Disable it again with --no-proxy-insecure. Example: curl --proxy-insecure -x See also _-x,_ _--proxy_ and _-k,_ _--insecure_. Added in 7.52.0. ### --proxy-key-type Same as _--key-type_ but used in HTTPS proxy context. If _--proxy-key-type_ is provided several times, the last set value is used. Example: curl --proxy-key-type DER --proxy-key here -x See also _--proxy-key_ and _-x,_ _--proxy_. Added in 7.52.0. ### --proxy-key Same as _--key_ but used in HTTPS proxy context. If _--proxy-key_ is provided several times, the last set value is used. Example: curl --proxy-key here -x See also _--proxy-key-type_ and _-x,_ _--proxy_. Added in 7.52.0. ### --proxy-negotiate Tells curl to use HTTP Negotiate (SPNEGO) authentication when communicating with the given proxy. Use _--negotiate_ for enabling HTTP Negotiate (SPNEGO) with a remote host. Providing _--proxy-negotiate_ multiple times has no extra effect. Example: curl --proxy-negotiate --proxy-user user:passwd -x proxy See also _--proxy-anyauth_ and _--proxy-basic_. ### --proxy-ntlm Tells curl to use HTTP NTLM authentication when communicating with the given proxy. Use _--ntlm_ for enabling NTLM with a remote host. Providing _--proxy-ntlm_ multiple times has no extra effect. Example: curl --proxy-ntlm --proxy-user user:passwd -x See also _--proxy-negotiate_ and _--proxy-anyauth_. ### --proxy-pass Same as _--pass_ but used in HTTPS proxy context. If _--proxy-pass_ is provided several times, the last set value is used. Example: curl --proxy-pass secret --proxy-key here -x See also _-x,_ _--proxy_ and _--proxy-key_. Added in 7.52.0. ### --proxy-pinnedpubkey (TLS) Tells curl to use the specified public key file (or hashes) to verify the proxy. This can be a path to a file which contains a single public key in PEM or DER format, or any number of base64 encoded sha256 hashes preceded by 'sha256//' and separated by ';'. When negotiating a TLS or SSL connection, the server sends a certificate indicating its identity. A public key is extracted from this certificate and if it does not ex‐ actly match the public key provided to this option, curl aborts the connection before sending or receiving any data. If _--proxy-pinnedpubkey_ is provided several times, the last set value is used. Examples: curl --proxy-pinnedpubkey keyfile curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' See also _--pinnedpubkey_ and _-x,_ _--proxy_. Added in 7.59.0. ### --proxy-service-name This option allows you to change the service name for proxy negotiation. If _--proxy-service-name_ is provided several times, the last set value is used. Example: curl --proxy-service-name "shrubbery" -x proxy See also _--service-name_ and _-x,_ _--proxy_. ### --proxy-ssl-allow-beast Same as _--ssl-allow-beast_ but used in HTTPS proxy context. Providing _--proxy-ssl-allow-beast_ multiple times has no extra effect. Disable it again with --no-proxy-ssl-allow-beast. Example: curl --proxy-ssl-allow-beast -x See also _--ssl-allow-beast_ and _-x,_ _--proxy_. Added in 7.52.0. ### --proxy-ssl-auto-client-cert Same as _--ssl-auto-client-cert_ but used in HTTPS proxy context. Providing _--proxy-ssl-auto-client-cert_ multiple times has no extra effect. Disable it again with --no-proxy-ssl-auto-client-cert. Example: curl --proxy-ssl-auto-client-cert -x See also _--ssl-auto-client-cert_ and _-x,_ _--proxy_. Added in 7.77.0. ### --proxy-tls13-ciphers (TLS) Specifies which cipher suites to use in the connection to your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers suites must specify valid ciphers. Read up on TLS 1.3 cipher suite details on this URL: This option is currently used only when curl is built to use OpenSSL 1.1.1 or later. If you are using a different SSL backend you can try setting TLS 1.3 cipher suites by using the _--proxy-ciphers_ option. If _--proxy-tls13-ciphers_ is provided several times, the last set value is used. Example: curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy See also _--tls13-ciphers_, _--curves_ and _--proxy-ciphers_. Added in 7.61.0. ### --proxy-tlsauthtype Same as _--tlsauthtype_ but used in HTTPS proxy context. If _--proxy-tlsauthtype_ is provided several times, the last set value is used. Example: curl --proxy-tlsauthtype SRP -x See also _-x,_ _--proxy_ and _--proxy-tlsuser_. Added in 7.52.0. ### --proxy-tlspassword Same as _--tlspassword_ but used in HTTPS proxy context. If _--proxy-tlspassword_ is provided several times, the last set value is used. Example: curl --proxy-tlspassword passwd -x See also _-x,_ _--proxy_ and _--proxy-tlsuser_. Added in 7.52.0. ### --proxy-tlsuser Same as _--tlsuser_ but used in HTTPS proxy context. If _--proxy-tlsuser_ is provided several times, the last set value is used. Example: curl --proxy-tlsuser smith -x See also _-x,_ _--proxy_ and _--proxy-tlspassword_. Added in 7.52.0. ### --proxy-tlsv1 Same as _-1,_ _--tlsv1_ but used in HTTPS proxy context. Providing _--proxy-tlsv1_ multiple times has no extra effect. Example: curl --proxy-tlsv1 -x See also _-x,_ _--proxy_. Added in 7.52.0. ### -U, --proxy-user Specify the user name and password to use for proxy authentication. If you use a Windows SSPI-enabled curl binary and do either Negotiate or NTLM authen‐ tication then you can tell curl to select the user name and password from your envi‐ ronment by specifying a single colon with this option: "-U :". On systems where it works, curl hides the given option argument from process listings. This is not enough to protect credentials from possibly getting seen by other users on the same system as they still are visible for a moment before cleared. Such sensitive data should be retrieved from a file instead or similar and never used in clear text in a command line. If _-U,_ _--proxy-user_ is provided several times, the last set value is used. Example: curl --proxy-user name:pwd -x proxy See also _--proxy-pass_. -x, --proxy [protocol://]host[:port] Use the specified proxy. The proxy string can be specified with a protocol:// prefix. No protocol specified or http:// it is treated as an HTTP proxy. Use socks4://, socks4a://, socks5:// or socks5h:// to request a specific SOCKS version to be used. Unix domain sockets are supported for socks proxy. Set localhost for the host part. e.g. socks5h://localhost/path/to/socket.sock HTTPS proxy support works set with the https:// protocol prefix for OpenSSL and GnuTLS (added in 7.52.0). It also works for BearSSL, mbedTLS, rustls, Schannel, Secure Trans‐ port and wolfSSL (added in 7.87.0). Unrecognized and unsupported proxy protocols cause an error (added in 7.52.0). An‐ cient curl versions ignored unknown schemes and used http:// instead. If the port number is not specified in the proxy string, it is assumed to be 1080. This option overrides existing environment variables that set the proxy to use. If there is an environment variable setting a proxy, you can set proxy to "" to override it. All operations that are performed over an HTTP proxy are transparently converted to HTTP. It means that certain protocol specific operations might not be available. This is not the case if you can tunnel through the proxy, as one with the _-p,_ _--proxytunnel_ option. User and password that might be provided in the proxy string are URL decoded by curl. This allows you to pass in special characters such as @ by using %40 or pass in a colon with %3a. The proxy host can be specified the same way as the proxy environment variables, in‐ cluding the protocol prefix (http://) and the embedded user + password. When a proxy is used, the active FTP mode as set with _-P,_ _--ftp-port_, cannot be used. If _-x,_ _--proxy_ is provided several times, the last set value is used. Example: curl --proxy See also _--socks5_ and _--proxy-basic_. --proxy1.0 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 at‐ tempts to use CONNECT through the proxy specifies an HTTP 1.0 protocol instead of the default HTTP 1.1. Providing _--proxy1.0_ multiple times has no extra effect. Example: curl --proxy1.0 -x See also _-x,_ _--proxy_, _--socks5_ and _--preproxy_. ### -p, --proxytunnel When an HTTP proxy is used _-x,_ _--proxy_, this option makes curl tunnel the traffic through the proxy. The tunnel approach is made with the HTTP proxy CONNECT request and requires that the proxy allows direct connect to the remote port number curl wants to tunnel through to. To suppress proxy CONNECT response headers when curl is set to output headers use _--suppress-connect-headers_. Providing _-p,_ _--proxytunnel_ multiple times has no extra effect. Disable it again with --no-proxytunnel. Example: curl --proxytunnel -x See also _-x,_ _--proxy_. ### --pubkey (SFTP SCP) Public key file name. Allows you to provide your public key in this sepa‐ rate file. curl attempts to automatically extract the public key from the private key file, so passing this option is generally not required. Note that this public key extraction requires libcurl to be linked against a copy of libssh2 1.2.8 or higher that is itself linked against OpenSSL. If _--pubkey_ is provided several times, the last set value is used. Example: curl --pubkey file.pub sftp://example.com/ See also _--pass_. ### -Q, --quote (FTP SFTP) Send an arbitrary command to the remote FTP or SFTP server. Quote commands are sent BEFORE the transfer takes place (just after the initial **PWD **command in an FTP transfer, to be exact). To make commands take place after a successful transfer, pre‐ fix them with a dash '-'. (FTP only) To make commands be sent after curl has changed the working directory, just before the file transfer command(s), prefix the command with a '+'. This is not per‐ formed when a directory listing is performed. You may specify any number of commands. By default curl stops at first failure. To make curl continue even if the command fails, prefix the command with an asterisk (*). Otherwise, if the server returns fail‐ ure for one of the commands, the entire operation is aborted. You must send syntactically correct FTP commands as RFC 959 defines to FTP servers, or one of the commands listed below to SFTP servers. SFTP is a binary protocol. Unlike for FTP, curl interprets SFTP quote commands itself before sending them to the server. File names may be quoted shell-style to embed spaces or special characters. Following is the list of all supported SFTP quote com‐ mands: "atime date file" The atime command sets the last access time of the file named by the file operand. The can be all sorts of date strings, see the [_curl_getdate(3)](https://www.chedong.com/phpMan.php/man/curlgetdate/3/markdown)_ man page for date expression details. (Added in 7.73.0) "chgrp group file" The chgrp command sets the group ID of the file named by the file operand to the group ID specified by the group operand. The group operand is a decimal in‐ teger group ID. "chmod mode file" The chmod command modifies the file mode bits of the specified file. The mode operand is an octal integer mode number. "chown user file" The chown command sets the owner of the file named by the file operand to the user ID specified by the user operand. The user operand is a decimal integer user ID. "ln source_file target_file" The ln and symlink commands create a symbolic link at the target_file location pointing to the source_file location. "mkdir directory_name" The mkdir command creates the directory named by the directory_name operand. "mtime date file" The mtime command sets the last modification time of the file named by the file operand. The can be all sorts of date strings, see the [_curl_getdate(3)](https://www.chedong.com/phpMan.php/man/curlgetdate/3/markdown)_ man page for date expression details. (Added in 7.73.0) **"pwd" **The pwd command returns the absolute path name 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 operand, provided it is empty. "symlink source_file target_file" See ln. _-Q,_ _--quote_ can be used several times in a command line Example: curl --quote "DELE file" ftp://example.com/foo See also _-X,_ _--request_. ### --random-file Deprecated option. This option is ignored (added in 7.84.0). Prior to that it only had an effect on curl if built to use old versions of OpenSSL. Specify the path name to file containing random data. The data may be used to seed the random engine for SSL connections. If _--random-file_ is provided several times, the last set value is used. Example: curl --random-file rubbish See also _--egd-file_. ### -r, --range (HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial document) from an HTTP/1.1, FTP or SFTP server or a local FILE. Ranges can be specified in a number of ways. **0-499 **specifies the first 500 bytes **500-999 **specifies the second 500 bytes **-500 **specifies the last 500 bytes **9500- **specifies the bytes from offset 9500 and forward **0-0,-1 **specifies the first and last byte only(*)(HTTP) **100-199,500-599** specifies two separate 100-byte ranges(*) (HTTP) (*) = NOTE that this causes the server to reply with a multipart response, which is returned as-is by curl! Parsing or otherwise transforming this response is the respon‐ sibility of the caller. Only digit characters (0-9) are valid in the 'start' and 'stop' fields of the 'start-stop' range syntax. If a non-digit character is given in the range, the server's response is unspecified, depending on the server's configuration. Many HTTP/1.1 servers do not have this feature enabled, so that when you attempt to get a range, curl instead gets the whole document. FTP and SFTP range downloads only support the simple 'start-stop' syntax (optionally with one of the numbers omitted). FTP use depends on the extended FTP command SIZE. If _-r,_ _--range_ is provided several times, the last set value is used. Example: curl --range 22-44 See also _-C,_ _--continue-at_ and _-a,_ _--append_. ### --rate Specify the maximum transfer frequency you allow curl to use - in number of transfer starts per time unit (sometimes called request rate). Without this option, curl starts the next transfer as fast as possible. If given several URLs and a transfer completes faster than the allowed rate, curl waits until the next transfer is started to maintain the requested rate. This option has no effect when _-Z,_ _--parallel_ is used. The request rate is provided as "N/U" where N is an integer number and U is a time unit. Supported units are 's' (second), 'm' (minute), 'h' (hour) and 'd' /(day, as in a 24 hour unit). The default time unit, if no "/U" is provided, is number of transfers per hour. If curl is told to allow 10 requests per minute, it does not start the next request until 6 seconds have elapsed since the previous transfer was started. This function uses millisecond resolution. If the allowed frequency is set more than 1000 per second, it instead runs unrestricted. When retrying transfers, enabled with _--retry_, the separate retry delay logic is used and not this setting. This option is global and does not need to be specified for each use of --next. If _--rate_ is provided several times, the last set value is used. Examples: curl --rate 2/s ... curl --rate 3/h ... curl --rate 14/m ... See also _--limit-rate_ and _--retry-delay_. Added in 7.84.0. --raw (HTTP) When used, it disables all internal HTTP decoding of content or transfer encod‐ ings and instead makes them passed on unaltered, raw. Providing _--raw_ multiple times has no extra effect. Disable it again with --no-raw. Example: curl --raw See also _--tr-encoding_. ### -e, --referer (HTTP) Sends the "Referrer Page" information to the HTTP server. This can also be set with the _-H,_ _--header_ flag of course. When used with _-L,_ _--location_ you can append ";auto" to the _-e,_ _--referer_ URL to make curl automatically set the previous URL when it follows a Location: header. The ";auto" string can be used alone, even if you do not set an initial _-e,_ _--referer_. If _-e,_ _--referer_ is provided several times, the last set value is used. Examples: curl --referer "" curl --referer "" -L curl --referer ";auto" -L See also _-A,_ _--user-agent_ and _-H,_ _--header_. ### -J, --remote-header-name (HTTP) This option tells the _-O,_ _--remote-name_ option to use the server-specified Con‐ tent-Disposition filename instead of extracting a filename from the URL. If the server-provided file name contains a path, that is stripped off before the file name is used. The file is saved in the current directory, or in the directory specified with _--out‐_ _put-dir_. If the server specifies a file name and a file with that name already exists in the destination directory, it is not overwritten and an error occurs - unless you allow it by using the --clobber option. If the server does not specify a file name then this option has no effect. There is no attempt to decode %-sequences (yet) in the provided file name, so this op‐ tion may provide you with rather unexpected file names. This feature uses the name from the "filename" field, it does not yet support the "filename*" field (filenames with explicit character sets). **WARNING**: Exercise judicious use of this option, especially on Windows. A rogue server could send you the name of a DLL or other file that could be loaded automatically by Windows or some third party software. Providing _-J,_ _--remote-header-name_ multiple times has no extra effect. Disable it again with --no-remote-header-name. Example: curl -OJ See also _-O,_ _--remote-name_. ### --remote-name-all This option changes the default action for all given URLs to be dealt with as if _-O,_ _--remote-name_ were used for each one. So if you want to disable that for a specific URL after _--remote-name-all_ has been used, you must use "-o -" or --no-remote-name. Providing _--remote-name-all_ multiple times has no extra effect. Disable it again with --no-remote-name-all. Example: curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2 See also _-O,_ _--remote-name_. ### -O, --remote-name Write output to a local file named like the remote file we get. (Only the file part of the remote file is used, the path is cut off.) The file is saved in the current working directory. If you want the file saved in a different directory, make sure you change the current working directory before invok‐ ing curl with this option or use _--output-dir_. The remote file name to use for saving is extracted from the given URL, nothing else, and if it already exists it is overwritten. If you want the server to be able to choose the file name refer to _-J,_ _--remote-header-name_ which can be used in addition to this option. If the server chooses a file name and that name already exists it is not overwritten. There is no URL decoding done on the file name. If it has %20 or other URL encoded parts of the name, they end up as-is as file name. You may use this option as many times as the number of URLs you have. _-O,_ _--remote-name_ can be used several times in a command line Example: curl -O See also _--remote-name-all_, _--output-dir_ and _-J,_ _--remote-header-name_. ### -R, --remote-time Makes curl attempt to figure out the timestamp of the remote file that is getting downloaded, and if that is available make the local file get that same timestamp. Providing _-R,_ _--remote-time_ multiple times has no extra effect. Disable it again with --no-remote-time. Example: curl --remote-time -o foo See also _-O,_ _--remote-name_ and _-z,_ _--time-cond_. ### --remove-on-error When curl returns an error when told to save output in a local file, this option re‐ moves that saved file before exiting. This prevents curl from leaving a partial file in the case of an error during transfer. If the output is not a file, this option has no effect. Providing _--remove-on-error_ multiple times has no extra effect. Disable it again with --no-remove-on-error. Example: curl --remove-on-error -o output See also _-f,_ _--fail_. Added in 7.83.0. ### --request-target (HTTP) Tells curl to use an alternative "target" (path) instead of using the path as provided in the URL. Particularly useful when wanting to issue HTTP requests without leading slash or other data that does not follow the regular URL pattern, like "OP‐ TIONS *". curl passes on the verbatim string you give it its the request without any filter or other safe guards. That includes white space and control characters. If _--request-target_ is provided several times, the last set value is used. Example: curl --request-target "*" -X OPTIONS See also _-X,_ _--request_. Added in 7.55.0. ### -X, --request Change the method to use when starting the transfer. curl passes on the verbatim string you give it its the request without any filter or other safe guards. That includes white space and control characters. **HTTP **Specifies a custom request method to use when communicating with the HTTP server. The specified request method is used instead of the method otherwise used (which defaults to _GET_). Read the HTTP 1.1 specification for details and explanations. Common additional HTTP requests include _PUT_ and _DELETE_, but related technologies like WebDAV offers _PROPFIND_, _COPY_, _MOVE_ and more. Normally you do not need this option. All sorts of _GET_, _HEAD_, _POST_ and _PUT_ requests are rather invoked by using dedicated command line op‐ tions. This option only changes the actual word used in the HTTP request, it does not alter the way curl behaves. So for example if you want to make a proper HEAD request, using -X HEAD does not suffice. You need to use the _-I,_ _--head_ option. The method string you set with _-X,_ _--request_ is used for all requests, which if you for example use _-L,_ _--location_ may cause unintended side-effects when curl does not change request method according to the HTTP 30x response codes - and similar. **FTP **Specifies a custom FTP command to use instead of _LIST_ when doing file lists with FTP. **POP3 **Specifies a custom POP3 command to use instead of _LIST_ or _RETR_. **IMAP **Specifies a custom IMAP command to use instead of _LIST_. **SMTP **Specifies a custom SMTP command to use instead of _HELP_ or **VRFY**. If _-X,_ _--request_ is provided several times, the last set value is used. Examples: curl -X "DELETE" curl -X NLST ftp://example.com/ See also _--request-target_. --resolve <[+]host:port:addr[,addr]...> Provide a custom address for a specific host and port pair. Using this, you can make the curl requests(s) use a specified address and prevent the otherwise normally re‐ solved address to be used. Consider it a sort of /etc/hosts alternative provided on the command line. The port number should be the number used for the specific protocol the host is used for. It means you need several entries if you want to provide address for the same host but different ports. By specifying '*' as host you can tell curl to resolve any host and specific port pair to the specified address. Wildcard is resolved last so any _--resolve_ with a specific host and port is used first. The provided address set by this option is used even if _-4,_ _--ipv4_ or _-6,_ _--ipv6_ is set to make curl use another IP version. By prefixing the host with a '+' you can make the entry time out after curl's default timeout (1 minute). Note that this only makes sense for long running parallel trans‐ fers with a lot of files. In such cases, if this option is used curl tries to resolve the host as it normally would once the timeout has expired. Support for providing the IP address within [brackets] was added in 7.57.0. Support for providing multiple IP addresses per entry was added in 7.59.0. Support for resolving with wildcard was added in 7.64.0. Support for the '+' prefix was was added in 7.75.0. _--resolve_ can be used several times in a command line Example: curl --resolve example.com:443:127.0.0.1 See also _--connect-to_ and _--alt-svc_. ### --retry-all-errors Retry on any error. This option is used together with _--retry_. This option is the "sledgehammer" of retrying. Do not use this option by default (for example in your **curlrc**), there may be unintended consequences such as sending or re‐ ceiving duplicate data. Do not use with redirected input or output. You'd be much bet‐ ter off handling your unique problems in shell script. Please read the example below. **WARNING**: For server compatibility curl attempts to retry failed flaky transfers as close as possible to how they were started, but this is not possible with redirected input or output. For example, before retrying it removes output data from a failed partial transfer that was written to an output file. However this is not true of data redirected to a | pipe or > file, which are not reset. We strongly suggest you do not parse or record output via redirect in combination with this option, since you may re‐ ceive duplicate data. By default curl does not return error for transfers with an HTTP response code that indicates an HTTP error, if the transfer was successful. For example, if a server replies 404 Not Found and the reply is fully received then that is not an error. When _--retry_ is used then curl retries on some HTTP response codes that indicate transient HTTP errors, but that does not include most 4xx response codes such as 404. If you want to retry on all response codes that indicate HTTP errors (4xx and 5xx) then com‐ bine with _-f,_ _--fail_. Providing _--retry-all-errors_ multiple times has no extra effect. Disable it again with --no-retry-all-errors. Example: curl --retry 5 --retry-all-errors See also _--retry_. Added in 7.71.0. ### --retry-connrefused In addition to the other conditions, consider ECONNREFUSED as a transient error too for _--retry_. This option is used together with _--retry_. Providing _--retry-connrefused_ multiple times has no extra effect. Disable it again with --no-retry-connrefused. Example: curl --retry-connrefused --retry 7 See also _--retry_ and _--retry-all-errors_. Added in 7.52.0. ### --retry-delay Make curl sleep this amount of time before each retry when a transfer has failed with a transient error (it changes the default backoff time algorithm between retries). This option is only interesting if _--retry_ is also used. Setting this delay to zero makes curl use the default backoff time. If _--retry-delay_ is provided several times, the last set value is used. Example: curl --retry-delay 5 --retry 7 See also _--retry_. ### --retry-max-time The retry timer is reset before the first transfer attempt. Retries are done as usual (see _--retry_) as long as the timer has not reached this given limit. Notice that if the timer has not reached the limit, the request is made and while performing, it may take longer than this given time period. To limit a single request's maximum time, use _-m,_ _--max-time_. Set this option to zero to not timeout retries. If _--retry-max-time_ is provided several times, the last set value is used. Example: curl --retry-max-time 30 --retry 10 See also _--retry_. ### --retry If a transient error is returned when curl tries to perform a transfer, it retries this number of times before giving up. Setting the number to 0 makes curl do no re‐ tries (which is the default). Transient error means either: a timeout, an FTP 4xx re‐ sponse code or an HTTP 408, 429, 500, 502, 503 or 504 response code. When curl is about to retry a transfer, it first waits one second and then for all forthcoming retries it doubles the waiting time until it reaches 10 minutes which then remains delay between the rest of the retries. By using _--retry-delay_ you disable this exponential backoff algorithm. See also _--retry-max-time_ to limit the total time al‐ lowed for retries. curl complies with the Retry-After: response header if one was present to know when to issue the next retry (added in 7.66.0). If _--retry_ is provided several times, the last set value is used. Example: curl --retry 7 See also _--retry-max-time_. ### --sasl-authzid Use this authorization identity (**authzid**), during SASL PLAIN authentication, in addi‐ tion to the authentication identity (**authcid**) as specified by _-u,_ _--user_. If the option is not specified, the server derives the **authzid **from the **authcid**, but if specified, and depending on the server implementation, it may be used to access an‐ other user's inbox, that the user has been granted access to, or a shared mailbox for example. If _--sasl-authzid_ is provided several times, the last set value is used. Example: curl --sasl-authzid zid imap://example.com/ See also _--login-options_. Added in 7.66.0. ### --sasl-ir Enable initial response in SASL authentication. Providing _--sasl-ir_ multiple times has no extra effect. Disable it again with --no-sasl-ir. Example: curl --sasl-ir imap://example.com/ See also _--sasl-authzid_. ### --service-name This option allows you to change the service name for SPNEGO. If _--service-name_ is provided several times, the last set value is used. Example: curl --service-name sockd/server See also _--negotiate_ and _--proxy-service-name_. ### -S, --show-error When used with _-s,_ _--silent_, it makes curl show an error message if it fails. This option is global and does not need to be specified for each use of --next. Providing _-S,_ _--show-error_ multiple times has no extra effect. Disable it again with --no-show-error. Example: curl --show-error --silent See also _--no-progress-meter_. ### -s, --silent Silent or quiet mode. Do not show progress meter or error messages. Makes Curl mute. It still outputs the data you ask for, potentially even to the terminal/stdout unless you redirect it. Use _-S,_ _--show-error_ in addition to this option to disable progress meter but still show error messages. Providing _-s,_ _--silent_ multiple times has no extra effect. Disable it again with --no-silent. Example: curl -s See also _-v,_ _--verbose_, _--stderr_ and _--no-progress-meter_. --socks4 Use the specified SOCKS4 proxy. If the port number is not specified, it is assumed at port 1080. Using this socket type make curl resolve the host name and passing the ad‐ dress on to the proxy. To specify proxy on a unix domain socket, use localhost for host, e.g. socks4://lo‐ calhost/path/to/socket.sock This option overrides any previous use of _-x,_ _--proxy_, as they are mutually exclusive. This option is superfluous since you can specify a socks4 proxy with _-x,_ _--proxy_ using a socks4:// protocol prefix. _--preproxy_ can be used to specify a SOCKS proxy at the same time proxy is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. If _--socks4_ is provided several times, the last set value is used. Example: curl --socks4 hostname:4096 See also _--socks4a_, _--socks5_ and _--socks5-hostname_. --socks4a Use the specified SOCKS4a proxy. If the port number is not specified, it is assumed at port 1080. This asks the proxy to resolve the host name. To specify proxy on a unix domain socket, use localhost for host, e.g. socks4a://lo‐ calhost/path/to/socket.sock This option overrides any previous use of _-x,_ _--proxy_, as they are mutually exclusive. This option is superfluous since you can specify a socks4a proxy with _-x,_ _--proxy_ us‐ ing a socks4a:// protocol prefix. _--preproxy_ can be used to specify a SOCKS proxy at the same time _-x,_ _--proxy_ is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. If _--socks4a_ is provided several times, the last set value is used. Example: curl --socks4a hostname:4096 See also _--socks4_, _--socks5_ and _--socks5-hostname_. ### --socks5-basic Tells curl to use username/password authentication when connecting to a SOCKS5 proxy. The username/password authentication is enabled by default. Use _--socks5-gssapi_ to force GSS-API authentication to SOCKS5 proxies. Providing _--socks5-basic_ multiple times has no extra effect. Example: curl --socks5-basic --socks5 hostname:4096 See also _--socks5_. Added in 7.55.0. ### --socks5-gssapi-nec As part of the GSS-API negotiation a protection mode is negotiated. RFC 1961 says in section 4.3/4.4 it should be protected, but the NEC reference implementation does not. The option _--socks5-gssapi-nec_ allows the unprotected exchange of the protection mode negotiation. Providing _--socks5-gssapi-nec_ multiple times has no extra effect. Disable it again with --no-socks5-gssapi-nec. Example: curl --socks5-gssapi-nec --socks5 hostname:4096 See also _--socks5_. ### --socks5-gssapi-service The default service name for a socks server is **rcmd/server-fqdn**. This option allows you to change it. If _--socks5-gssapi-service_ is provided several times, the last set value is used. Example: curl --socks5-gssapi-service sockd --socks5 hostname:4096 See also _--socks5_. ### --socks5-gssapi Tells curl to use GSS-API authentication when connecting to a SOCKS5 proxy. The GSS-API authentication is enabled by default (if curl is compiled with GSS-API sup‐ port). Use _--socks5-basic_ to force username/password authentication to SOCKS5 prox‐ ies. Providing _--socks5-gssapi_ multiple times has no extra effect. Disable it again with --no-socks5-gssapi. Example: curl --socks5-gssapi --socks5 hostname:4096 See also _--socks5_. Added in 7.55.0. --socks5-hostname Use the specified SOCKS5 proxy (and let the proxy resolve the host name). If the port number is not specified, it is assumed at port 1080. To specify proxy on a unix domain socket, use localhost for host, e.g. socks5h://lo‐ calhost/path/to/socket.sock This option overrides any previous use of _-x,_ _--proxy_, as they are mutually exclusive. This option is superfluous since you can specify a socks5 hostname proxy with _-x,_ _--proxy_ using a socks5h:// protocol prefix. _--preproxy_ can be used to specify a SOCKS proxy at the same time _-x,_ _--proxy_ is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. If _--socks5-hostname_ is provided several times, the last set value is used. Example: curl --socks5-hostname proxy.example:7000 See also _--socks5_ and _--socks4a_. --socks5 Use the specified SOCKS5 proxy - but resolve the host name locally. If the port number is not specified, it is assumed at port 1080. To specify proxy on a unix domain socket, use localhost for host, e.g. socks5://lo‐ calhost/path/to/socket.sock This option overrides any previous use of _-x,_ _--proxy_, as they are mutually exclusive. This option is superfluous since you can specify a socks5 proxy with _-x,_ _--proxy_ using a socks5:// protocol prefix. _--preproxy_ can be used to specify a SOCKS proxy at the same time _-x,_ _--proxy_ is used with an HTTP/HTTPS proxy (added in 7.52.0). In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. This option (as well as _--socks4_) does not work with IPV6, FTPS or LDAP. If _--socks5_ is provided several times, the last set value is used. Example: curl --socks5 proxy.example:7000 See also _--socks5-hostname_ and _--socks4a_. ### -Y, --speed-limit If a transfer is slower than this given speed (in bytes per second) for speed-time seconds it gets aborted. speed-time is set with _-y,_ _--speed-time_ and is 30 if not set. If _-Y,_ _--speed-limit_ is provided several times, the last set value is used. Example: curl --speed-limit 300 --speed-time 10 See also _-y,_ _--speed-time_, _--limit-rate_ and _-m,_ _--max-time_. ### -y, --speed-time If a transfer runs slower than speed-limit bytes per second during a speed-time pe‐ riod, the transfer is aborted. If speed-time is used, the default speed-limit is 1 un‐ less set with _-Y,_ _--speed-limit_. This option controls transfers (in both directions) but does not affect slow connects etc. If this is a concern for you, try the _--connect-timeout_ option. If _-y,_ _--speed-time_ is provided several times, the last set value is used. Example: curl --speed-limit 300 --speed-time 10 See also _-Y,_ _--speed-limit_ and _--limit-rate_. ### --ssl-allow-beast This option tells curl to not work around a security flaw in the SSL3 and TLS1.0 pro‐ tocols known as BEAST. If this option is not used, the SSL layer may use workarounds known to cause interoperability problems with some older SSL implementations. **WARNING**: this option loosens the SSL security, and by using this flag you ask for ex‐ actly that. Providing _--ssl-allow-beast_ multiple times has no extra effect. Disable it again with --no-ssl-allow-beast. Example: curl --ssl-allow-beast See also _--proxy-ssl-allow-beast_ and _-k,_ _--insecure_. ### --ssl-auto-client-cert (Schannel) Tell libcurl to automatically locate and use a client certificate for au‐ thentication, when requested by the server. Since the server can request any certifi‐ cate that supports client authentication in the OS certificate store it could be a privacy violation and unexpected. Providing _--ssl-auto-client-cert_ multiple times has no extra effect. Disable it again with --no-ssl-auto-client-cert. Example: curl --ssl-auto-client-cert See also _--proxy-ssl-auto-client-cert_. Added in 7.77.0. ### --ssl-no-revoke (Schannel) This option tells curl to disable certificate revocation checks. WARNING: this option loosens the SSL security, and by using this flag you ask for exactly that. Providing _--ssl-no-revoke_ multiple times has no extra effect. Disable it again with --no-ssl-no-revoke. Example: curl --ssl-no-revoke See also _--crlfile_. ### --ssl-reqd (FTP IMAP POP3 SMTP LDAP) Require SSL/TLS for the connection. Terminates the connec‐ tion if the transfer cannot be upgraded to use SSL/TLS. This option is handled in LDAP (added in 7.81.0). It is fully supported by the OpenL‐ DAP backend and rejected by the generic ldap backend if explicit TLS is required. This option is unnecessary if you use a URL scheme that in itself implies immediate and implicit use of TLS, like for FTPS, IMAPS, POP3S, SMTPS and LDAPS. Such a transfer always fails if the TLS handshake does not work. This option was formerly known as --ftp-ssl-reqd. Providing _--ssl-reqd_ multiple times has no extra effect. Disable it again with --no-ssl-reqd. Example: curl --ssl-reqd ftp://example.com See also _--ssl_ and _-k,_ _--insecure_. ### --ssl-revoke-best-effort (Schannel) This option tells curl to ignore certificate revocation checks when they failed due to missing/offline distribution points for the revocation check lists. Providing _--ssl-revoke-best-effort_ multiple times has no extra effect. Disable it again with --no-ssl-revoke-best-effort. Example: curl --ssl-revoke-best-effort See also _--crlfile_ and _-k,_ _--insecure_. Added in 7.70.0. --ssl (FTP IMAP POP3 SMTP LDAP) Warning: this is considered an insecure option. Consider us‐ ing _--ssl-reqd_ instead to be sure curl upgrades to a secure connection. Try to use SSL/TLS for the connection. Reverts to a non-secure connection if the server does not support SSL/TLS. See also _--ftp-ssl-control_ and _--ssl-reqd_ for differ‐ ent levels of encryption required. This option is handled in LDAP (added in 7.81.0). It is fully supported by the OpenL‐ DAP backend and ignored by the generic ldap backend. Please note that a server may close the connection if the negotiation does not suc‐ ceed. This option was formerly known as --ftp-ssl. That option name can still be used but might be removed in a future version. Providing _--ssl_ multiple times has no extra effect. Disable it again with --no-ssl. Example: curl --ssl pop3://example.com/ See also _--ssl-reqd_, _-k,_ _--insecure_ and _--ciphers_. -2, --sslv2 (SSL) This option previously asked curl to use SSLv2, but is now ignored (added in 7.77.0). SSLv2 is widely considered insecure (see RFC 6176). Providing _-2,_ _--sslv2_ multiple times has no extra effect. Example: curl --sslv2 See also _--http1.1_ and _--http2_. _-2,_ _--sslv2_ requires that the underlying libcurl was built to support TLS. This option is mutually exclusive to _-3,_ _--sslv3_ and _-1,_ _--tlsv1_ and _--tlsv1.1_ and _--tlsv1.2_. -3, --sslv3 (SSL) This option previously asked curl to use SSLv3, but is now ignored (added in 7.77.0). SSLv3 is widely considered insecure (see RFC 7568). Providing _-3,_ _--sslv3_ multiple times has no extra effect. Example: curl --sslv3 See also _--http1.1_ and _--http2_. _-3,_ _--sslv3_ requires that the underlying libcurl was built to support TLS. This option is mutually exclusive to _-2,_ _--sslv2_ and _-1,_ _--tlsv1_ and _--tlsv1.1_ and _--tlsv1.2_. ### --stderr Redirect all writes to stderr to the specified file instead. If the file name is a plain '-', it is instead written to stdout. This option is global and does not need to be specified for each use of --next. If _--stderr_ is provided several times, the last set value is used. Example: curl --stderr output.txt See also _-v,_ _--verbose_ and _-s,_ _--silent_. ### --styled-output Enables the automatic use of bold font styles when writing HTTP headers to the termi‐ nal. Use --no-styled-output to switch them off. Styled output requires a terminal that supports bold fonts. This feature is not present on curl for Windows due to lack of this capability. This option is global and does not need to be specified for each use of --next. Providing _--styled-output_ multiple times has no extra effect. Disable it again with --no-styled-output. Example: curl --styled-output -I See also _-I,_ _--head_ and _-v,_ _--verbose_. Added in 7.61.0. ### --suppress-connect-headers When _-p,_ _--proxytunnel_ is used and a CONNECT request is made do not output proxy CON‐ NECT response headers. This option is meant to be used with _-D,_ _--dump-header_ or _-i,_ _--include_ which are used to show protocol headers in the output. It has no effect on debug options such as _-v,_ _--verbose_ or _--trace_, or any statistics. Providing _--suppress-connect-headers_ multiple times has no extra effect. Disable it again with --no-suppress-connect-headers. Example: curl --suppress-connect-headers --include -x proxy See also _-D,_ _--dump-header_, _-i,_ _--include_ and _-p,_ _--proxytunnel_. Added in 7.54.0. ### --tcp-fastopen Enable use of TCP Fast Open (RFC 7413). TCP Fast Open is a TCP extension that allows data to get sent earlier over the connection (before the final handshake ACK) if the client and server have been connected previously. Providing _--tcp-fastopen_ multiple times has no extra effect. Disable it again with --no-tcp-fastopen. Example: curl --tcp-fastopen See also _--false-start_. ### --tcp-nodelay Turn on the TCP_NODELAY option. See the [_curl_easy_setopt(3)](https://www.chedong.com/phpMan.php/man/curleasysetopt/3/markdown)_ man page for details about this option. curl sets this option by default and you need to explicitly switch it off if you do not want it on (added in 7.50.2). Providing _--tcp-nodelay_ multiple times has no extra effect. Disable it again with --no-tcp-nodelay. Example: curl --tcp-nodelay See also _-N,_ _--no-buffer_. ### -t, --telnet-option Pass options to the telnet protocol. Supported options are: **TTYPE**= Sets the terminal type. **XDISPLOC**= Sets the X display location. **NEW_ENV**= Sets an environment variable. _-t,_ _--telnet-option_ can be used several times in a command line Example: curl -t TTYPE=vt100 telnet://example.com/ See also _-K,_ _--config_. ### --tftp-blksize (TFTP) Set the TFTP **BLKSIZE **option (must be >512). This is the block size that curl tries to use when transferring data to or from a TFTP server. By default 512 bytes are used. If _--tftp-blksize_ is provided several times, the last set value is used. Example: curl --tftp-blksize 1024 tftp://example.com/file See also _--tftp-no-options_. ### --tftp-no-options (TFTP) Tells curl not to send TFTP options requests. This option improves interop with some legacy servers that do not acknowledge or prop‐ erly implement TFTP options. When this option is used _--tftp-blksize_ is ignored. Providing _--tftp-no-options_ multiple times has no extra effect. Disable it again with --no-tftp-no-options. Example: curl --tftp-no-options tftp://192.168.0.1/ See also _--tftp-blksize_. ### -z, --time-cond