.\" You can view this file with: .\" nroff -man curl.1 .\" Written by Daniel Stenberg .\" .TH curl 1 "20 September 2000" "Curl 7.3" "Curl Manual" .SH NAME curl \- get a URL with FTP, TELNET, LDAP, GOPHER, DICT, FILE, HTTP or HTTPS syntax. .SH SYNOPSIS .B curl [options] .I url .SH DESCRIPTION .B curl is a client to get documents/files from servers, using any of the supported protocols. The command is designed to work without user interaction or any kind of interactivity. curl offers a busload of useful tricks like proxy support, user authentication, ftp upload, HTTP post, SSL (https:) connections, cookies, file transfer resume and more. .SH URL The URL syntax is protocol dependent. You'll find a detailed description in RFC 2396. You can specify multiple URLs or parts of URLs by writing part sets within braces as in: http://site.{one,two,three}.com or you can get sequences of alphanumeric series by using [] as in: ftp://ftp.numericals.com/file[1-100].txt ftp://ftp.numericals.com/file[001-100].txt (with leading zeros) ftp://ftp.letters.com/file[a-z].txt It is possible to specify up to 9 sets or series for a URL, but no nesting is supported at the moment: http://www.any.org/archive[1996-1999]/volume[1-4]part{a,b,c,index}.html .SH OPTIONS .IP "-a/--append" (FTP) When used in a ftp upload, this will tell curl to append to the target file instead of overwriting it. If the file doesn't exist, it will be created. .IP "-A/--user-agent " (HTTP) Specify the User-Agent string to send to the HTTP server. Some badly done CGIs fail if its not set to "Mozilla/4.0". To encode blanks in the string, surround the string with single quote marks. This can also be set with the -H/--header flag of course. .IP "-b/--cookie " (HTTP) Pass the data to the HTTP server as a cookie. It is supposedly the data previously received from the server in a "Set-Cookie:" line. The data should be in the format "NAME1=VALUE1; NAME2=VALUE2". If no '=' letter is used in the line, it is treated as a filename to use to read previously stored cookie lines from, which should be used in this session if they match. Using this method also activates the "cookie parser" which will make curl record incoming cookies too, which may be handy if you're using this in combination with the -L/--location option. The file format of the file to read cookies from should be plain HTTP headers or the netscape cookie file format. .B NOTE that the file specified with -b/--cookie is only used as input. No cookies will be stored in the file. To store cookies, save the HTTP headers to a file using -D/--dump-header! .IP "-B/--use-ascii" Use ASCII transfer when getting an FTP file or LDAP info. For FTP, this can also be enforced by using an URL that ends with ";type=A". This option causes data sent to stdout to be in text mode for win32 systems. .IP "-c/--continue" Continue/Resume a previous file transfer. This instructs curl to continue appending data on the file where it was previously left, possibly because of a broken connection to the server. There must be a named physical file to append to for this to work. Note: Upload resume is depening on a command named SIZE not always present in all ftp servers! Upload resume is for FTP only. HTTP resume is only possible with HTTP/1.1 or later servers. .IP "-C/--continue-at " Continue/Resume a previous file transfer at the given offset. The given offset is the exact number of bytes that will be skipped counted from the beginning of the source file before it is transfered to the destination. If used with uploads, the ftp server command SIZE will not be used by curl. Upload resume is for FTP only. HTTP resume is only possible with HTTP/1.1 or later servers. .IP "-d/--data " (HTTP) Sends the specified data in a POST request to the HTTP server. Note that the data is sent exactly as specified with no extra processing (with all newlines cut off). The data is expected to be "url-encoded". This will cause curl to pass the data to the server using the content-type application/x-www-form-urlencoded. Compare to -F. If you start the data with the letter @, the rest should be a file name to read the data from, or - if you want curl to read the data from stdin. The contents of the file must already be url-encoded. To post data purely binary, you should instead use the --data-binary option. -d/--data is the same as --data-ascii. .IP "--data-ascii " (HTTP) This is an alias for the -d/--data option. .IP "--data-binary " (HTTP) This posts data in a similar manner as --data-ascii does, although when using this option the entire context of the posted data is kept as-is. If you want to post a binary file without the strip-newlines feature of the --data-ascii option, this is for you. .IP "-D/--dump-header " (HTTP/FTP) Write the HTTP headers to this file. Write the FTP file info to this file if -I/--head is used. This option is handy to use when you want to store the cookies that a HTTP site sends to you. The cookies could then be read in a second curl invoke by using the -b/--cookie option! .IP "-e/--referer " (HTTP) Sends the "Referer Page" information to the HTTP server. This can also be set with the -H/--header flag of course. When used with .I -L/--location you can append ";auto" to the referer URL to make curl automatically set the previous URL when it follows a Location: header. The ";auto" string can be used alone, even if you don't set an initial referer. .IP "-E/--cert " (HTTPS) Tells curl to use the specified certificate file when getting a file with HTTPS. The certificate must be in PEM format. If the optional password isn't specified, it will be queried for on the terminal. Note that this certificate is the private key and the private certificate concatenated! .IP "-f/--fail" (HTTP) Fail silently (no output at all) on server errors. This is mostly done like this to better enable scripts etc to better deal with failed attempts. In normal cases when a HTTP server fails to deliver a document, it returns a HTML document stating so (which often also describes why and more). This flag will prevent curl from outputting that and fail silently instead. .IP "-F/--form " (HTTP) This lets curl emulate a filled in form in which a user has pressed the submit button. This causes curl to POST data using the content-type multipart/form-data according to RFC1867. This enables uploading of binary files etc. To force the 'content' part to be 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 letter <. The difference between @ and < is then that @ makes a file get attached in the post as a file upload, while the < makes a text field and just get the contents for that text field from a file. Example, to send your password file to the server, where 'password' is the name of the form-field to which /etc/passwd will be the input: .B curl -F password=@/etc/passwd www.mypasswords.com To read the file's content from stdin insted of a file, use - where the file name should've been. This goes for both @ and < constructs. .IP "-h/--help" Usage help. .IP "-H/--header
" (HTTP) Extra header to use when getting a web page. You may specify any number of extra headers. Note that if you should add a custom header that has the same name as one of the internal ones curl would use, your externally set header will be used instead of the internal one. This allows you to make even trickier stuff than curl would normally do. You should not replace internally set headers without knowing perfectly well what you're doing. Replacing an internal header with one without content on the right side of the colon will prevent that header from appearing. .IP "-i/--include" (HTTP) Include the HTTP-header in the output. The HTTP-header includes things like server-name, date of the document, HTTP-version and more... .IP "--interface " Perform an operation using a specified interface. You can enter interface name, IP address or host name. An example could look like: .B "curl --interface eth0:1 http://www.netscape.com/" .IP "-I/--head" (HTTP/FTP) Fetch the HTTP-header only! HTTP-servers feature the command HEAD which this uses to get nothing but the header of a document. When used on a FTP file, curl displays the file size only. .IP "--krb4 " (FTP) Enable kerberos4 authentication and use. The level must be entered and should be one of 'clear', 'safe', 'confidential' or 'private'. Should you use a level that is not one of these, 'private' will instead be used. .IP "-K/--config " Specify which config file to read curl arguments from. The config file is a text file in which command line arguments can be written which then will be used as if they were written on the actual command line. If the first column of a config line is a '#' character, the rest of the line will be treated as a comment. Specify the filename as '-' to make curl read the file from stdin. .IP "-l/--list-only" (FTP) When listing an FTP directory, this switch forces a name-only view. Especially useful if you want to machine-parse the contents of an FTP directory since the normal directory view doesn't use a standard look or format. .IP "-L/--location" (HTTP/HTTPS) If the server reports that the requested page has a different location (indicated with the header line Location:) this flag will let curl attempt to reattempt the get on the new place. If used together with -i or -I, headers from all requested pages will be shown. If this flag is used when making a HTTP POST, curl will automatically switch to GET after the initial POST has been done. .IP "-m/--max-time " Maximum time in seconds that you allow the whole operation to take. This is useful for preventing your batch jobs from hanging for hours due to slow networks or links going down. This doesn't work fully in win32 systems. .IP "-M/--manual" Manual. Display the huge help text. .IP "-n/--netrc" Makes curl scan the .I .netrc file in the user's home directory for login name and password. This is typically used for ftp on unix. If used with http, curl will enable user authentication. See .BR netrc(4) for details on the file format. Curl will not complain if that file hasn't the right permissions (it should not be world nor group readable). The environment variable "HOME" is used to find the home directory. A quick and very simple example of how to setup a .I .netrc to allow curl to ftp to the machine host.domain.com with user name 'myself' and password 'secret' should look similar to: .B "machine host.domain.com login myself password secret" .IP "-N/--no-buffer" Disables the buffering of the output stream. In normal work situations, curl will use a standard buffered output stream that will have the effect that it will output the data in chunks, not necessarily exactly when the data arrives. Using this option will disable that buffering. .IP "-o/--output " Write output to instead of stdout. If you are using {} or [] to fetch multiple documents, you can use '#' followed by a number in the specifier. That variable will be replaced with the current string for the URL being fetched. Like in: curl http://{one,two}.site.com -o "file_#1.txt" or use several variables like: curl http://{site,host}.host[1-5].com -o "#1_#2" .IP "-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.) .IP "-p/--proxytunnel" When an HTTP proxy is used, this option will cause non-HTTP protocols to attempt to tunnel through the proxy instead of merely using it to do HTTP-like operations. The tunnel approach is made with the HTTP proxy CONNECT request and requires that the proxy allows direct connect to the remote port number curl wants to tunnel through to. .IP "-P/--ftpport
" (FTP) Reverses the initiator/listener roles when connecting with ftp. This switch makes Curl use the PORT command instead of PASV. In practice, PORT tells the server to connect to the client's specified address and port, while PASV asks the server for an ip address and port to connect to.
should be one of: .RS .TP 12 .B interface i.e "eth0" to specify which interface's IP address you want to use (Unix only) .TP .B "IP address" i.e "192.168.10.1" to specify exact IP number .TP .B "host name" i.e "my.host.domain" to specify machine .TP .B "-" (any single-letter string) to make it pick the machine's default .RE .IP "-q" If used as the first parameter on the command line, the .I $HOME/.curlrc file will not be read and used as a config file. .IP "-Q/--quote " (FTP) Send an arbitrary command to the remote FTP server, by using the QUOTE command of the server. Not all servers support this command, and the set of QUOTE commands are server specific! Quote commands are sent BEFORE the transfer is taking place. To make commands take place after a successful transfer, prefix them with a dash '-'. You may specify any amount of commands to be run before and after the transfer. If the server returns failure for one of the commands, the entire operation will be aborted. .IP "-r/--range " (HTTP/FTP) Retrieve a byte range (i.e a partial document) from a HTTP/1.1 or FTP server. Ranges can be specified in a number of ways. .RS .TP 10 .B 0-499 specifies the first 500 bytes .TP .B 500-999 specifies the second 500 bytes .TP .B -500 specifies the last 500 bytes .TP .B 9500 specifies the bytes from offset 9500 and forward .TP .B 0-0,-1 specifies the first and last byte only(*)(H) .TP .B 500-700,600-799 specifies 300 bytes from offset 500(H) .TP .B 100-199,500-599 specifies two separate 100 bytes ranges(*)(H) .RE (*) = NOTE that this will cause the server to reply with a multipart response! You should also be aware that many HTTP/1.1 servers do not have this feature enabled, so that when you attempt to get a range, you'll instead get the whole document. FTP range downloads only support the simple syntax 'start-stop' (optionally with one of the numbers omitted). It depends on the non-RFC command SIZE. .IP "-s/--silent" Silent mode. Don't show progress meter or error messages. Makes Curl mute. .IP "-S/--show-error" When used with -s it makes curl show error message if it fails. .IP "-t/--upload" Transfer the stdin data to the specified file. Curl will read everything from stdin until EOF and store with the supplied name. If this is used on a http(s) server, the PUT command will be used. .IP "-T/--upload-file " Like -t, but this transfers the specified local file. If there is no file part in the specified URL, Curl will append the local file name. NOTE that you must use a trailing / on the last directory to really prove to Curl that there is no file name or curl will think that your last directory name is the remote file name to use. That will most likely cause the upload operation to fail. If this is used on a http(s) server, the PUT command will be used. .IP "-u/--user " Specify user and password to use when fetching. See README.curl for detailed examples of how to use this. If no password is specified, curl will ask for it interactively. .IP "-U/--proxy-user " Specify user and password to use for Proxy authentication. If no password is specified, curl will ask for it interactively. .IP "-v/--verbose" Makes the fetching more verbose/talkative. Mostly usable for debugging. Lines starting with '>' means data sent by curl, '<' means data received by curl that is hidden in normal cases and lines starting with '*' means additional info provided by curl. .IP "-V/--version" Displays the full version of curl, libcurl and other 3rd party libraries linked with the executable. .IP "-w/--write-out " Defines what to display after a completed and successful operation. The format is a string that may contain plain text mixed with any number of variables. The string can be specified as "string", to get read from a particular file you specify it "@filename" and to tell curl to read the format from stdin you write "@-". The variables present in the output format will be substituted by the value or text that curl thinks fit, as described below. All variables are specified like %{variable_name} and to output a normal % you just write them like %%. You can output a newline by using \\n, a carrige return with \\r and a tab space with \\t. .B NOTE: The %-letter is a special letter in the win32-environment, where all occurrences of % must be doubled when using this option. Available variables are at this point: .RS .TP 15 .B url_effective The URL that was fetched last. This is mostly meaningful if you've told curl to follow location: headers. .TP .B http_code The numerical code that was found in the last retrieved HTTP(S) page. .TP .B time_total The total time, in seconds, that the full operation lasted. The time will be displayed with millisecond resolution. .TP .B time_namelookup The time, in seconds, it took from the start until the name resolving was completed. .TP .B time_connect The time, in seconds, it took from the start until the connect to the remote host (or proxy) was completed. .TP .B time_pretransfer The time, in seconds, it took from the start until the file transfer is just about to begin. This includes all pre-transfer commands and negotiations that are specific to the particular protocol(s) involved. .TP .B size_download The total amount of bytes that were downloaded. .TP .B size_upload The total amount of bytes that were uploaded. .TP .B speed_download The average download speed that curl measured for the complete download. .TP .B speed_upload The average upload speed that curl measured for the complete download. .RE .IP "-x/--proxy " Use specified proxy. If the port number is not specified, it is assumed at port 1080. .IP "-X/--request " (HTTP) Specifies a custom request to use when communicating with the HTTP server. The specified request will be used instead of the standard GET. Read the HTTP 1.1 specification for details and explanations. (FTP) Specifies a custom FTP command to use instead of LIST when doing file lists with ftp. .IP "-y/--speed-time