3 You always find news about what's going on as well as the latest versions
4 from the curl web pages, located at:
10 Get the main page from Netscape's web-server:
12 curl http://www.netscape.com/
14 Get the README file the user's home directory at funet's ftp-server:
16 curl ftp://ftp.funet.fi/README
18 Get a web page from a server using port 8000:
20 curl http://www.weirdserver.com:8000/
22 Get a directory listing of an FTP site:
24 curl ftp://cool.haxx.se/
26 Get the definition of curl from a dictionary:
28 curl dict://dict.org/m:curl
30 Fetch two documents at once:
32 curl ftp://cool.haxx.se/ http://www.weirdserver.com:8000/
34 Get a file off an FTPS server:
36 curl ftps://files.are.secure.com/secrets.txt
38 or use the more appropriate FTPS way to get the same file:
40 curl --ftp-ssl ftp://files.are.secure.com/secrets.txt
42 Get a file from an SSH server using SFTP:
44 curl -u username sftp://shell.example.com/etc/issue
46 Get a file from an SSH server using SCP using a private key to authenticate:
48 curl -u username: --key ~/.ssh/id_dsa --pubkey ~/.ssh/id_dsa.pub \
49 scp://shell.example.com/~/personal.txt
51 Get the main page from an IPv6 web server:
53 curl "http://[2001:1890:1112:1::20]/"
57 Get a web page and store in a local file with a specific name:
59 curl -o thatpage.html http://www.netscape.com/
61 Get a web page and store in a local file, make the local file get the name
62 of the remote document (if no file name part is specified in the URL, this
65 curl -O http://www.netscape.com/index.html
67 Fetch two files and store them with their remote names:
69 curl -O www.haxx.se/index.html -O curl.haxx.se/download.html
75 To ftp files using name+passwd, include them in the URL like:
77 curl ftp://name:passwd@machine.domain:port/full/path/to/file
79 or specify them with the -u flag like
81 curl -u name:passwd ftp://machine.domain:port/full/path/to/file
85 It is just like for FTP, but you may also want to specify and use
86 SSL-specific options for certificates etc.
88 Note that using FTPS:// as prefix is the "implicit" way as described in the
89 standards while the recommended "explicit" way is done by using FTP:// and
94 This is similar to FTP, but you can specify a private key to use instead of
95 a password. Note that the private key may itself be protected by a password
96 that is unrelated to the login password of the remote system. If you
97 provide a private key file you must also provide a public key file.
101 Curl also supports user and password in HTTP URLs, thus you can pick a file
104 curl http://name:passwd@machine.domain/full/path/to/file
106 or specify user and password separately like in
108 curl -u name:passwd http://machine.domain/full/path/to/file
110 HTTP offers many different methods of authentication and curl supports
111 several: Basic, Digest, NTLM and Negotiate. Without telling which method to
112 use, curl defaults to Basic. You can also ask curl to pick the most secure
113 ones out of the ones that the server accepts for the given URL, by using
116 NOTE! According to the URL specification, HTTP URLs can not contain a user
117 and password, so that style will not work when using curl via a proxy, even
118 though curl allows it at other times. When using a proxy, you _must_ use
119 the -u style for user and password.
123 Probably most commonly used with private certificates, as explained below.
127 curl supports both HTTP and SOCKS proxy servers, with optional authentication.
128 It does not have special support for FTP proxy servers since there are no
129 standards for those, but it can still be made to work with many of them. You
130 can also use both HTTP and SOCKS proxies to transfer files to and from FTP
133 Get an ftp file using an HTTP proxy named my-proxy that uses port 888:
135 curl -x my-proxy:888 ftp://ftp.leachsite.com/README
137 Get a file from an HTTP server that requires user and password, using the
140 curl -u user:passwd -x my-proxy:888 http://www.get.this/
142 Some proxies require special authentication. Specify by using -U as above:
144 curl -U user:passwd -x my-proxy:888 http://www.get.this/
146 A comma-separated list of hosts and domains which do not use the proxy can
149 curl --noproxy localhost,get.this -x my-proxy:888 http://www.get.this/
151 If the proxy is specified with --proxy1.0 instead of --proxy or -x, then
152 curl will use HTTP/1.0 instead of HTTP/1.1 for any CONNECT attempts.
154 curl also supports SOCKS4 and SOCKS5 proxies with --socks4 and --socks5.
156 See also the environment variables Curl supports that offer further proxy
159 Most FTP proxy servers are set up to appear as a normal FTP server from the
160 client's perspective, with special commands to select the remote FTP server.
161 curl supports the -u, -Q and --ftp-account options that can be used to
162 set up transfers through many FTP proxies. For example, a file can be
163 uploaded to a remote FTP server using a Blue Coat FTP proxy with the
166 curl -u "Remote-FTP-Username@remote.ftp.server Proxy-Username:Remote-Pass" \
167 --ftp-account Proxy-Password --upload-file local-file \
168 ftp://my-ftp.proxy.server:21/remote/upload/path/
170 See the manual for your FTP proxy to determine the form it expects to set up
171 transfers, and curl's -v option to see exactly what curl is sending.
175 HTTP 1.1 introduced byte-ranges. Using this, a client can request
176 to get only one or more subparts of a specified document. Curl supports
177 this with the -r flag.
179 Get the first 100 bytes of a document:
181 curl -r 0-99 http://www.get.this/
183 Get the last 500 bytes of a document:
185 curl -r -500 http://www.get.this/
187 Curl also supports simple ranges for FTP files as well. Then you can only
188 specify start and stop position.
190 Get the first 100 bytes of a document using FTP:
192 curl -r 0-99 ftp://www.get.this/README
196 FTP / FTPS / SFTP / SCP
198 Upload all data on stdin to a specified server:
200 curl -T - ftp://ftp.upload.com/myfile
202 Upload data from a specified file, login with user and password:
204 curl -T uploadfile -u user:passwd ftp://ftp.upload.com/myfile
206 Upload a local file to the remote site, and use the local file name at the remote
209 curl -T uploadfile -u user:passwd ftp://ftp.upload.com/
211 Upload a local file to get appended to the remote file:
213 curl -T localfile -a ftp://ftp.upload.com/remotefile
215 Curl also supports ftp upload through a proxy, but only if the proxy is
216 configured to allow that kind of tunneling. If it does, you can run curl in
217 a fashion similar to:
219 curl --proxytunnel -x proxy:port -T localfile ftp.upload.com
223 Upload all data on stdin to a specified HTTP site:
225 curl -T - http://www.upload.com/myfile
227 Note that the HTTP server must have been configured to accept PUT before
228 this can be done successfully.
230 For other ways to do HTTP data upload, see the POST section below.
234 If curl fails where it isn't supposed to, if the servers don't let you in,
235 if you can't understand the responses: use the -v flag to get verbose
236 fetching. Curl will output lots of info and what it sends and receives in
237 order to let the user see all client-server interaction (but it won't show
238 you the actual data).
240 curl -v ftp://ftp.upload.com/
242 To get even more details and information on what curl does, try using the
243 --trace or --trace-ascii options with a given file name to log to, like
246 curl --trace trace.txt www.haxx.se
251 Different protocols provide different ways of getting detailed information
252 about specific files/documents. To get curl to show detailed information
253 about a single file, you should use -I/--head option. It displays all
254 available info on a single file for HTTP and FTP. The HTTP information is a
257 For HTTP, you can get the header information (the same as -I would show)
258 shown before the data by using -i/--include. Curl understands the
259 -D/--dump-header option when getting files from both FTP and HTTP, and it
260 will then store the headers in the specified file.
262 Store the HTTP headers in a separate file (headers.txt in the example):
264 curl --dump-header headers.txt curl.haxx.se
266 Note that headers stored in a separate file can be very useful at a later
267 time if you want curl to use cookies sent by the server. More about that in
272 It's easy to post data using curl. This is done using the -d <data>
273 option. The post data must be urlencoded.
275 Post a simple "name" and "phone" guestbook.
277 curl -d "name=Rafael%20Sagula&phone=3320780" \
278 http://www.where.com/guest.cgi
280 How to post a form with curl, lesson #1:
282 Dig out all the <input> tags in the form that you want to fill in. (There's
283 a perl program called formfind.pl on the curl site that helps with this).
285 If there's a "normal" post, you use -d to post. -d takes a full "post
286 string", which is in the format
288 <variable1>=<data1>&<variable2>=<data2>&...
290 The 'variable' names are the names set with "name=" in the <input> tags, and
291 the data is the contents you want to fill in for the inputs. The data *must*
292 be properly URL encoded. That means you replace space with + and that you
293 replace weird letters with %XX where XX is the hexadecimal representation of
294 the letter's ASCII code.
298 (page located at http://www.formpost.com/getthis/
300 <form action="post.cgi" method="post">
301 <input name=user size=10>
302 <input name=pass type=password size=10>
303 <input name=id type=hidden value="blablabla">
304 <input name=ding value="submit">
307 We want to enter user 'foobar' with password '12345'.
309 To post to this, you enter a curl command line like:
311 curl -d "user=foobar&pass=12345&id=blablabla&ding=submit" (continues)
312 http://www.formpost.com/getthis/post.cgi
315 While -d uses the application/x-www-form-urlencoded mime-type, generally
316 understood by CGI's and similar, curl also supports the more capable
317 multipart/form-data type. This latter type supports things like file upload.
319 -F accepts parameters like -F "name=contents". If you want the contents to
320 be read from a file, use <@filename> as contents. When specifying a file,
321 you can also specify the file content type by appending ';type=<mime type>'
322 to the file name. You can also post the contents of several files in one
323 field. For example, the field name 'coolfiles' is used to send three files,
324 with different content types using the following syntax:
326 curl -F "coolfiles=@fil1.gif;type=image/gif,fil2.txt,fil3.html" \
327 http://www.post.com/postit.cgi
329 If the content-type is not specified, curl will try to guess from the file
330 extension (it only knows a few), or use the previously specified type (from
331 an earlier file if several files are specified in a list) or else it will
332 use the default type 'application/octet-stream'.
334 Emulate a fill-in form with -F. Let's say you fill in three fields in a
335 form. One field is a file name which to post, one field is your name and one
336 field is a file description. We want to post the file we have written named
337 "cooltext.txt". To let curl do the posting of this data instead of your
338 favourite browser, you have to read the HTML source of the form page and
339 find the names of the input fields. In our example, the input field names
340 are 'file', 'yourname' and 'filedescription'.
342 curl -F "file=@cooltext.txt" -F "yourname=Daniel" \
343 -F "filedescription=Cool text file with cool text inside" \
344 http://www.post.com/postit.cgi
346 To send two files in one post you can do it in two ways:
348 1. Send multiple files in a single "field" with a single field name:
350 curl -F "pictures=@dog.gif,cat.gif"
352 2. Send two fields with two field names:
354 curl -F "docpicture=@dog.gif" -F "catpicture=@cat.gif"
356 To send a field value literally without interpreting a leading '@'
357 or '<', or an embedded ';type=', use --form-string instead of
358 -F. This is recommended when the value is obtained from a user or
359 some other unpredictable source. Under these circumstances, using
360 -F instead of --form-string would allow a user to trick curl into
365 An HTTP request has the option to include information about which address
366 referred it to the actual page. Curl allows you to specify the
367 referrer to be used on the command line. It is especially useful to
368 fool or trick stupid servers or CGI scripts that rely on that information
369 being available or contain certain data.
371 curl -e www.coolsite.com http://www.showme.com/
373 NOTE: The Referer: [sic] field is defined in the HTTP spec to be a full URL.
377 An HTTP request has the option to include information about the browser
378 that generated the request. Curl allows it to be specified on the command
379 line. It is especially useful to fool or trick stupid servers or CGI
380 scripts that only accept certain browsers.
384 curl -A 'Mozilla/3.0 (Win95; I)' http://www.nationsbank.com/
386 Other common strings:
387 'Mozilla/3.0 (Win95; I)' Netscape Version 3 for Windows 95
388 'Mozilla/3.04 (Win95; U)' Netscape Version 3 for Windows 95
389 'Mozilla/2.02 (OS/2; U)' Netscape Version 2 for OS/2
390 'Mozilla/4.04 [en] (X11; U; AIX 4.2; Nav)' NS for AIX
391 'Mozilla/4.05 [en] (X11; U; Linux 2.0.32 i586)' NS for Linux
393 Note that Internet Explorer tries hard to be compatible in every way:
394 'Mozilla/4.0 (compatible; MSIE 4.01; Windows 95)' MSIE for W95
396 Mozilla is not the only possible User-Agent name:
397 'Konqueror/1.0' KDE File Manager desktop client
398 'Lynx/2.7.1 libwww-FM/2.14' Lynx command line browser
402 Cookies are generally used by web servers to keep state information at the
403 client's side. The server sets cookies by sending a response line in the
404 headers that looks like 'Set-Cookie: <data>' where the data part then
405 typically contains a set of NAME=VALUE pairs (separated by semicolons ';'
406 like "NAME1=VALUE1; NAME2=VALUE2;"). The server can also specify for what
407 path the "cookie" should be used for (by specifying "path=value"), when the
408 cookie should expire ("expire=DATE"), for what domain to use it
409 ("domain=NAME") and if it should be used on secure connections only
412 If you've received a page from a server that contains a header like:
413 Set-Cookie: sessionid=boo123; path="/foo";
415 it means the server wants that first pair passed on when we get anything in
416 a path beginning with "/foo".
418 Example, get a page that wants my name passed in a cookie:
420 curl -b "name=Daniel" www.sillypage.com
422 Curl also has the ability to use previously received cookies in following
423 sessions. If you get cookies from a server and store them in a file in a
426 curl --dump-header headers www.example.com
428 ... you can then in a second connect to that (or another) site, use the
429 cookies from the 'headers' file like:
431 curl -b headers www.example.com
433 While saving headers to a file is a working way to store cookies, it is
434 however error-prone and not the preferred way to do this. Instead, make curl
435 save the incoming cookies using the well-known netscape cookie format like
438 curl -c cookies.txt www.example.com
440 Note that by specifying -b you enable the "cookie awareness" and with -L
441 you can make curl follow a location: (which often is used in combination
442 with cookies). So that if a site sends cookies and a location, you can
443 use a non-existing file to trigger the cookie awareness like:
445 curl -L -b empty.txt www.example.com
447 The file to read cookies from must be formatted using plain HTTP headers OR
448 as netscape's cookie file. Curl will determine what kind it is based on the
449 file contents. In the above command, curl will parse the header and store
450 the cookies received from www.example.com. curl will send to the server the
451 stored cookies which match the request as it follows the location. The
452 file "empty.txt" may be a nonexistent file.
454 Alas, to both read and write cookies from a netscape cookie file, you can
455 set both -b and -c to use the same file:
457 curl -b cookies.txt -c cookies.txt www.example.com
461 The progress meter exists to show a user that something actually is
462 happening. The different fields in the output have the following meaning:
464 % Total % Received % Xferd Average Speed Time Curr.
465 Dload Upload Total Current Left Speed
466 0 151M 0 38608 0 0 9406 0 4:41:43 0:00:04 4:41:39 9287
469 % - percentage completed of the whole transfer
470 Total - total size of the whole expected transfer
471 % - percentage completed of the download
472 Received - currently downloaded amount of bytes
473 % - percentage completed of the upload
474 Xferd - currently uploaded amount of bytes
476 Dload - the average transfer speed of the download
478 Upload - the average transfer speed of the upload
479 Time Total - expected time to complete the operation
480 Time Current - time passed since the invoke
481 Time Left - expected time left to completion
482 Curr.Speed - the average transfer speed the last 5 seconds (the first
483 5 seconds of a transfer is based on less time of course.)
485 The -# option will display a totally different progress bar that doesn't
486 need much explanation!
490 Curl allows the user to set the transfer speed conditions that must be met
491 to let the transfer keep going. By using the switch -y and -Y you
492 can make curl abort transfers if the transfer speed is below the specified
493 lowest limit for a specified time.
495 To have curl abort the download if the speed is slower than 3000 bytes per
496 second for 1 minute, run:
498 curl -Y 3000 -y 60 www.far-away-site.com
500 This can very well be used in combination with the overall time limit, so
501 that the above operation must be completed in whole within 30 minutes:
503 curl -m 1800 -Y 3000 -y 60 www.far-away-site.com
505 Forcing curl not to transfer data faster than a given rate is also possible,
506 which might be useful if you're using a limited bandwidth connection and you
507 don't want your transfer to use all of it (sometimes referred to as
508 "bandwidth throttle").
510 Make curl transfer data no faster than 10 kilobytes per second:
512 curl --limit-rate 10K www.far-away-site.com
516 curl --limit-rate 10240 www.far-away-site.com
518 Or prevent curl from uploading data faster than 1 megabyte per second:
520 curl -T upload --limit-rate 1M ftp://uploadshereplease.com
522 When using the --limit-rate option, the transfer rate is regulated on a
523 per-second basis, which will cause the total transfer speed to become lower
524 than the given number. Sometimes of course substantially lower, if your
525 transfer stalls during periods.
529 Curl automatically tries to read the .curlrc file (or _curlrc file on win32
530 systems) from the user's home dir on startup.
532 The config file could be made up with normal command line switches, but you
533 can also specify the long options without the dashes to make it more
534 readable. You can separate the options and the parameter with spaces, or
535 with = or :. Comments can be used within the file. If the first letter on a
536 line is a '#'-symbol the rest of the line is treated as a comment.
538 If you want the parameter to contain spaces, you must enclose the entire
539 parameter within double quotes ("). Within those quotes, you specify a
542 NOTE: You must specify options and their arguments on the same line.
544 Example, set default time out and proxy in a config file:
546 # We want a 30 minute timeout:
548 # ... and we use a proxy for all accesses:
549 proxy = proxy.our.domain.com:8080
551 White spaces ARE significant at the end of lines, but all white spaces
552 leading up to the first characters of each line are ignored.
554 Prevent curl from reading the default file by using -q as the first command
555 line parameter, like:
557 curl -q www.thatsite.com
559 Force curl to get and display a local help page in case it is invoked
560 without URL by making a config file similar to:
563 url = "http://help.with.curl.com/curlhelp.html"
565 You can specify another config file to be read by using the -K/--config
566 flag. If you set config file name to "-" it'll read the config from stdin,
567 which can be handy if you want to hide options from being visible in process
570 echo "user = user:passwd" | curl -K - http://that.secret.site.com
574 When using curl in your own very special programs, you may end up needing
575 to pass on your own custom headers when getting a web page. You can do
576 this by using the -H flag.
578 Example, send the header "X-you-and-me: yes" to the server when getting a
581 curl -H "X-you-and-me: yes" www.love.com
583 This can also be useful in case you want curl to send a different text in a
584 header than it normally does. The -H header you specify then replaces the
585 header curl would normally send. If you replace an internal header with an
586 empty one, you prevent that header from being sent. To prevent the Host:
587 header from being used:
589 curl -H "Host:" www.server.com
593 Do note that when getting files with the ftp:// URL, the given path is
594 relative the directory you enter. To get the file 'README' from your home
595 directory at your ftp site, do:
597 curl ftp://user:passwd@my.site.com/README
599 But if you want the README file from the root directory of that very same
600 site, you need to specify the absolute file name:
602 curl ftp://user:passwd@my.site.com//README
604 (I.e with an extra slash in front of the file name.)
606 SFTP and SCP and PATH NAMES
608 With sftp: and scp: URLs, the path name given is the absolute name on the
609 server. To access a file relative to the remote user's home directory,
610 prefix the file with /~/ , such as:
612 curl -u $USER sftp://home.example.com/~/.bashrc
616 The FTP protocol requires one of the involved parties to open a second
617 connection as soon as data is about to get transferred. There are two ways to
620 The default way for curl is to issue the PASV command which causes the
621 server to open another port and await another connection performed by the
622 client. This is good if the client is behind a firewall that doesn't allow
623 incoming connections.
625 curl ftp.download.com
627 If the server, for example, is behind a firewall that doesn't allow connections
628 on ports other than 21 (or if it just doesn't support the PASV command), the
629 other way to do it is to use the PORT command and instruct the server to
630 connect to the client on the given IP number and port (as parameters to the
633 The -P flag to curl supports a few different options. Your machine may have
634 several IP-addresses and/or network interfaces and curl allows you to select
635 which of them to use. Default address can also be used:
637 curl -P - ftp.download.com
639 Download with PORT but use the IP address of our 'le0' interface (this does
640 not work on windows):
642 curl -P le0 ftp.download.com
644 Download with PORT but use 192.168.0.10 as our IP address to use:
646 curl -P 192.168.0.10 ftp.download.com
650 Get a web page from a server using a specified port for the interface:
652 curl --interface eth0:1 http://www.netscape.com/
656 curl --interface 192.168.1.10 http://www.netscape.com/
660 Secure HTTP requires SSL libraries to be installed and used when curl is
661 built. If that is done, curl is capable of retrieving and posting documents
662 using the HTTPS protocol.
666 curl https://www.secure-site.com
668 Curl is also capable of using your personal certificates to get/post files
669 from sites that require valid certificates. The only drawback is that the
670 certificate needs to be in PEM-format. PEM is a standard and open format to
671 store certificates with, but it is not used by the most commonly used
672 browsers (Netscape and MSIE both use the so called PKCS#12 format). If you
673 want curl to use the certificates you use with your (favourite) browser, you
674 may need to download/compile a converter that can convert your browser's
675 formatted certificates to PEM formatted ones. This kind of converter is
676 included in recent versions of OpenSSL, and for older versions Dr Stephen
677 N. Henson has written a patch for SSLeay that adds this functionality. You
678 can get his patch (that requires an SSLeay installation) from his site at:
679 http://www.drh-consultancy.demon.co.uk/
681 Example on how to automatically retrieve a document using a certificate with
684 curl -E /path/to/cert.pem:password https://secure.site.com/
686 If you neglect to specify the password on the command line, you will be
687 prompted for the correct password before any data can be received.
689 Many older SSL-servers have problems with SSLv3 or TLS, which newer versions
690 of OpenSSL etc use, therefore it is sometimes useful to specify what
691 SSL-version curl should use. Use -3, -2 or -1 to specify that exact SSL
692 version to use (for SSLv3, SSLv2 or TLSv1 respectively):
694 curl -2 https://secure.site.com/
696 Otherwise, curl will first attempt to use v3 and then v2.
698 To use OpenSSL to convert your favourite browser's certificate into a PEM
699 formatted one that curl can use, do something like this:
701 In Netscape, you start with hitting the 'Security' menu button.
703 Select 'certificates->yours' and then pick a certificate in the list
705 Press the 'Export' button
707 enter your PIN code for the certs
709 select a proper place to save it
711 Run the 'openssl' application to convert the certificate. If you cd to the
712 openssl installation, you can do it like:
714 # ./apps/openssl pkcs12 -in [file you saved] -clcerts -out [PEMfile]
716 In Firefox, select Options, then Advanced, then the Encryption tab,
717 View Certificates. This opens the Certificate Manager, where you can
718 Export. Be sure to select PEM for the Save as type.
720 In Internet Explorer, select Internet Options, then the Content tab, then
721 Certificates. Then you can Export, and depending on the format you may
722 need to convert to PEM.
724 In Chrome, select Settings, then Show Advanced Settings. Under HTTPS/SSL
725 select Manage Certificates.
727 RESUMING FILE TRANSFERS
729 To continue a file transfer where it was previously aborted, curl supports
730 resume on HTTP(S) downloads as well as FTP uploads and downloads.
732 Continue downloading a document:
734 curl -C - -o file ftp://ftp.server.com/path/file
736 Continue uploading a document(*1):
738 curl -C - -T file ftp://ftp.server.com/path/file
740 Continue downloading a document from a web server(*2):
742 curl -C - -o file http://www.server.com/
744 (*1) = This requires that the FTP server supports the non-standard command
745 SIZE. If it doesn't, curl will say so.
747 (*2) = This requires that the web server supports at least HTTP/1.1. If it
748 doesn't, curl will say so.
752 HTTP allows a client to specify a time condition for the document it
753 requests. It is If-Modified-Since or If-Unmodified-Since. Curl allows you to
754 specify them with the -z/--time-cond flag.
756 For example, you can easily make a download that only gets performed if the
757 remote file is newer than a local copy. It would be made like:
759 curl -z local.html http://remote.server.com/remote.html
761 Or you can download a file only if the local file is newer than the remote
762 one. Do this by prepending the date string with a '-', as in:
764 curl -z -local.html http://remote.server.com/remote.html
766 You can specify a "free text" date as condition. Tell curl to only download
767 the file if it was updated since January 12, 2012:
769 curl -z "Jan 12 2012" http://remote.server.com/remote.html
771 Curl will then accept a wide range of date formats. You always make the date
772 check the other way around by prepending it with a dash '-'.
778 curl dict://dict.org/m:curl
779 curl dict://dict.org/d:heisenbug:jargon
780 curl dict://dict.org/d:daniel:web1913
782 Aliases for 'm' are 'match' and 'find', and aliases for 'd' are 'define'
783 and 'lookup'. For example,
785 curl dict://dict.org/find:curl
787 Commands that break the URL description of the RFC (but not the DICT
790 curl dict://dict.org/show:db
791 curl dict://dict.org/show:strat
793 Authentication is still missing (but this is not required by the RFC)
797 If you have installed the OpenLDAP library, curl can take advantage of it
798 and offer ldap:// support.
800 LDAP is a complex thing and writing an LDAP query is not an easy task. I do
801 advise you to dig up the syntax description for that elsewhere. Two places
802 that might suit you are:
804 Netscape's "Netscape Directory SDK 3.0 for C Programmer's Guide Chapter 10:
805 Working with LDAP URLs":
806 http://developer.netscape.com/docs/manuals/dirsdk/csdk30/url.htm
808 RFC 2255, "The LDAP URL Format" http://curl.haxx.se/rfc/rfc2255.txt
810 To show you an example, this is how I can get all people from my local LDAP
811 server that has a certain sub-domain in their email address:
813 curl -B "ldap://ldap.frontec.se/o=frontec??sub?mail=*sth.frontec.se"
815 If I want the same info in HTML format, I can get it by not using the -B
816 (enforce ASCII) flag.
818 ENVIRONMENT VARIABLES
820 Curl reads and understands the following environment variables:
822 http_proxy, HTTPS_PROXY, FTP_PROXY
824 They should be set for protocol-specific proxies. General proxy should be
829 A comma-separated list of host names that shouldn't go through any proxy is
830 set in (only an asterisk, '*' matches all hosts)
834 If the host name matches one of these strings, or the host is within the
835 domain of one of these strings, transactions with that node will not be
839 The usage of the -x/--proxy flag overrides the environment variables.
843 Unix introduced the .netrc concept a long time ago. It is a way for a user
844 to specify name and password for commonly visited FTP sites in a file so
845 that you don't have to type them in each time you visit those sites. You
846 realize this is a big security risk if someone else gets hold of your
847 passwords, so therefore most unix programs won't read this file unless it is
848 only readable by yourself (curl doesn't care though).
850 Curl supports .netrc files if told to (using the -n/--netrc and
851 --netrc-optional options). This is not restricted to just FTP,
852 so curl can use it for all protocols where authentication is used.
854 A very simple .netrc file could look something like:
856 machine curl.haxx.se login iamdaniel password mysecret
860 To better allow script programmers to get to know about the progress of
861 curl, the -w/--write-out option was introduced. Using this, you can specify
862 what information from the previous transfer you want to extract.
864 To display the amount of bytes downloaded together with some text and an
867 curl -w 'We downloaded %{size_download} bytes\n' www.download.com
869 KERBEROS FTP TRANSFER
871 Curl supports kerberos4 and kerberos5/GSSAPI for FTP transfers. You need
872 the kerberos package installed and used at curl build time for it to be
875 First, get the krb-ticket the normal way, like with the kinit/kauth tool.
876 Then use curl in way similar to:
878 curl --krb private ftp://krb4site.com -u username:fakepwd
880 There's no use for a password on the -u switch, but a blank one will make
881 curl ask for one and you already entered the real password to kinit/kauth.
885 The curl telnet support is basic and very easy to use. Curl passes all data
886 passed to it on stdin to the remote server. Connect to a remote telnet
887 server using a command line similar to:
889 curl telnet://remote.server.com
891 And enter the data to pass to the server on stdin. The result will be sent
892 to stdout or to the file you specify with -o.
894 You might want the -N/--no-buffer option to switch off the buffered output
895 for slow connections or similar.
897 Pass options to the telnet protocol negotiation, by using the -t option. To
898 tell the server we use a vt100 terminal, try something like:
900 curl -tTTYPE=vt100 telnet://remote.server.com
902 Other interesting options for it -t include:
904 - XDISPLOC=<X display> Sets the X display location.
906 - NEW_ENV=<var,val> Sets an environment variable.
908 NOTE: The telnet protocol does not specify any way to login with a specified
909 user and password so curl can't do that automatically. To do that, you need
910 to track when the login prompt is received and send the username and
911 password accordingly.
913 PERSISTENT CONNECTIONS
915 Specifying multiple files on a single command line will make curl transfer
916 all of them, one after the other in the specified order.
918 libcurl will attempt to use persistent connections for the transfers so that
919 the second transfer to the same host can use the same connection that was
920 already initiated and was left open in the previous transfer. This greatly
921 decreases connection time for all but the first transfer and it makes a far
922 better use of the network.
924 Note that curl cannot use persistent connections for transfers that are used
925 in subsequence curl invokes. Try to stuff as many URLs as possible on the
926 same command line if they are using the same host, as that'll make the
927 transfers faster. If you use an HTTP proxy for file transfers, practically
928 all transfers will be persistent.
930 MULTIPLE TRANSFERS WITH A SINGLE COMMAND LINE
932 As is mentioned above, you can download multiple files with one command line
933 by simply adding more URLs. If you want those to get saved to a local file
934 instead of just printed to stdout, you need to add one save option for each
935 URL you specify. Note that this also goes for the -O option (but not
938 For example: get two files and use -O for the first and a custom file
941 curl -O http://url.com/file.txt ftp://ftp.com/moo.exe -o moo.jpg
943 You can also upload multiple files in a similar fashion:
945 curl -T local1 ftp://ftp.com/moo.exe -T local2 ftp://ftp.com/moo2.txt
949 curl will connect to a server with IPv6 when a host lookup returns an IPv6
950 address and fall back to IPv4 if the connection fails. The --ipv4 and --ipv6
951 options can specify which address to use when both are available. IPv6
952 addresses can also be specified directly in URLs using the syntax:
954 http://[2001:1890:1112:1::20]/overview.html
956 When this style is used, the -g option must be given to stop curl from
957 interpreting the square brackets as special globbing characters. Link local
958 and site local addresses including a scope identifier, such as fe80::1234%1,
959 may also be used, but the scope portion must be numeric or match an existing
960 network interface on Linux and the percent character must be URL escaped. The
961 previous example in an SFTP URL might look like:
963 sftp://[fe80::1234%251]/
965 IPv6 addresses provided other than in URLs (e.g. to the --proxy, --interface
966 or --ftp-port options) should not be URL encoded.
970 Curl supports Metalink (both version 3 and 4 (RFC 5854) are supported), a way
971 to list multiple URIs and hashes for a file. Curl will make use of the mirrors
972 listed within for failover if there are errors (such as the file or server not
973 being available). It will also verify the hash of the file after the download
974 completes. The Metalink file itself is downloaded and processed in memory and
975 not stored in the local file system.
977 Example to use a remote Metalink file:
979 curl --metalink http://www.example.com/example.metalink
981 To use a Metalink file in the local file system, use FILE protocol (file://):
983 curl --metalink file://example.metalink
985 Please note that if FILE protocol is disabled, there is no way to use a local
986 Metalink file at the time of this writing. Also note that if --metalink and
987 --include are used together, --include will be ignored. This is because including
988 headers in the response will break Metalink parser and if the headers are included
989 in the file described in Metalink file, hash check will fail.
993 For your convenience, we have several open mailing lists to discuss curl,
994 its development and things relevant to this. Get all info at
995 http://curl.haxx.se/mail/. Some of the lists available are:
999 Users of the command line tool. How to use it, what doesn't work, new
1000 features, related tools, questions, news, installations, compilations,
1001 running, porting etc.
1005 Developers using or developing libcurl. Bugs, extensions, improvements.
1009 Low-traffic. Only receives announcements of new public versions. At worst,
1010 that makes something like one or two mails per month, but usually only one
1011 mail every second month.
1015 Using the curl functions in PHP. Everything curl with a PHP angle. Or PHP
1020 Python hackers using curl with or without the python binding pycurl.
1022 Please direct curl questions, feature requests and trouble reports to one of
1023 these mailing lists instead of mailing any individual.