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 root README file from funet's ftp-server:
16 curl ftp://ftp.funet.fi/README
18 Get a gopher document from funet's gopher server:
20 curl gopher://gopher.funet.fi
22 Get a web page from a server using port 8000:
24 curl http://www.weirdserver.com:8000/
26 Get a list of the root directory of an FTP site:
28 curl ftp://ftp.fts.frontec.se/
30 Get the definition of curl from a dictionary:
32 curl dict://dict.org/m:curl
36 Get a web page and store in a local file:
38 curl -o thatpage.html http://www.netscape.com/
40 Get a web page and store in a local file, make the local file get the name
41 of the remote document (if no file name part is specified in the URL, this
44 curl -O http://www.netscape.com/index.html
50 To ftp files using name+passwd, include them in the URL like:
52 curl ftp://name:passwd@machine.domain:port/full/path/to/file
54 or specify them with the -u flag like
56 curl -u name:passwd ftp://machine.domain:port/full/path/to/file
60 The HTTP URL doesn't support user and password in the URL string. Curl
61 does support that anyway to provide a ftp-style interface and thus you can
64 curl http://name:passwd@machine.domain/full/path/to/file
66 or specify user and password separately like in
68 curl -u name:passwd http://machine.domain/full/path/to/file
70 NOTE! Since HTTP URLs don't support user and password, you can't use that
71 style when using Curl via a proxy. You _must_ use the -u style fetch
72 during such circumstances.
76 Probably most commonly used with private certificates, as explained below.
80 Curl features no password support for gopher.
84 Get an ftp file using a proxy named my-proxy that uses port 888:
86 curl -x my-proxy:888 ftp://ftp.leachsite.com/README
88 Get a file from a HTTP server that requires user and password, using the
91 curl -u user:passwd -x my-proxy:888 http://www.get.this/
93 Some proxies require special authentication. Specify by using -U as above:
95 curl -U user:passwd -x my-proxy:888 http://www.get.this/
97 See also the environment variables Curl support that offer further proxy
102 With HTTP 1.1 byte-ranges were introduced. Using this, a client can request
103 to get only one or more subparts of a specified document. Curl supports
104 this with the -r flag.
106 Get the first 100 bytes of a document:
108 curl -r 0-99 http://www.get.this/
110 Get the last 500 bytes of a document:
112 curl -r -500 http://www.get.this/
114 Curl also supports simple ranges for FTP files as well. Then you can only
115 specify start and stop position.
117 Get the first 100 bytes of a document using FTP:
119 curl -r 0-99 ftp://www.get.this/README
125 Upload all data on stdin to a specified ftp site:
127 curl -t ftp://ftp.upload.com/myfile
129 Upload data from a specified file, login with user and password:
131 curl -T uploadfile -u user:passwd ftp://ftp.upload.com/myfile
133 Upload a local file to the remote site, and use the local file name remote
136 curl -T uploadfile -u user:passwd ftp://ftp.upload.com/
138 Upload a local file to get appended to the remote file using ftp:
140 curl -T localfile -a ftp://ftp.upload.com/remotefile
142 Curl also supports ftp upload through a proxy, but only if the proxy is
143 configured to allow that kind of tunneling. If it does, you can run curl in
144 a fashion similar to:
146 curl --proxytunnel -x proxy:port -T localfile ftp.upload.com
150 Upload all data on stdin to a specified http site:
152 curl -t http://www.upload.com/myfile
154 Note that the http server must've been configured to accept PUT before this
155 can be done successfully.
157 For other ways to do http data upload, see the POST section below.
161 If curl fails where it isn't supposed to, if the servers don't let you
162 in, if you can't understand the responses: use the -v flag to get VERBOSE
163 fetching. Curl will output lots of info and all data it sends and
164 receives in order to let the user see all client-server interaction.
166 curl -v ftp://ftp.upload.com/
170 Different protocols provide different ways of getting detailed information
171 about specific files/documents. To get curl to show detailed information
172 about a single file, you should use -I/--head option. It displays all
173 available info on a single file for HTTP and FTP. The HTTP information is a
176 For HTTP, you can get the header information (the same as -I would show)
177 shown before the data by using -i/--include. Curl understands the
178 -D/--dump-header option when getting files from both FTP and HTTP, and it
179 will then store the headers in the specified file.
181 Store the HTTP headers in a separate file:
183 curl --dump-header headers.txt curl.haxx.se
185 Note that headers stored in a separate file can be very useful at a later
186 time if you want curl to use cookies sent by the server. More about that in
191 It's easy to post data using curl. This is done using the -d <data>
192 option. The post data must be urlencoded.
194 Post a simple "name" and "phone" guestbook.
196 curl -d "name=Rafael%20Sagula&phone=3320780" \
197 http://www.where.com/guest.cgi
199 How to post a form with curl, lesson #1:
201 Dig out all the <input> tags in the form that you want to fill in. (There's
202 a perl program called formfind.pl on the curl site that helps with this).
204 If there's a "normal" post, you use -d to post. -d takes a full "post
205 string", which is in the format
207 <variable1>=<data1>&<variable2>=<data2>&...
209 The 'variable' names are the names set with "name=" in the <input> tags, and
210 the data is the contents you want to fill in for the inputs. The data *must*
211 be properly URL encoded. That means you replace space with + and that you
212 write weird letters with %XX where XX is the hexadecimal representation of
213 the letter's ASCII code.
217 (page located at http://www.formpost.com/getthis/
219 <form action="post.cgi" method="post">
220 <input name=user size=10>
221 <input name=pass type=password size=10>
222 <input name=id type=hidden value="blablabla">
223 <input name=ding value="submit">
226 We want to enter user 'foobar' with password '12345'.
228 To post to this, you enter a curl command line like:
230 curl -d "user=foobar&pass=12345&id=blablabla&dig=submit" (continues)
231 http://www.formpost.com/getthis/post.cgi
234 While -d uses the application/x-www-form-urlencoded mime-type, generally
235 understood by CGI's and similar, curl also supports the more capable
236 multipart/form-data type. This latter type supports things like file upload.
238 -F accepts parameters like -F "name=contents". If you want the contents to
239 be read from a file, use <@filename> as contents. When specifying a file,
240 you can also specify which content type the file is, by appending
241 ';type=<mime type>' to the file name. You can also post contents of several
242 files in one field. So that the field name 'coolfiles' can be sent three
243 files with different content types in a manner similar to:
245 curl -F "coolfiles=@fil1.gif;type=image/gif,fil2.txt,fil3.html" \
246 http://www.post.com/postit.cgi
248 If content-type is not specified, curl will try to guess from the extension
249 (it only knows a few), or use the previously specified type (from an earlier
250 file if several files are specified in a list) or finally using the default
253 Emulate a fill-in form with -F. Let's say you fill in three fields in a
254 form. One field is a file name which to post, one field is your name and one
255 field is a file description. We want to post the file we have written named
256 "cooltext.txt". To let curl do the posting of this data instead of your
257 favourite browser, you have to check out the HTML of the form page to get to
258 know the names of the input fields. In our example, the input field names are
259 'file', 'yourname' and 'filedescription'.
261 curl -F "file=@cooltext.txt" -F "yourname=Daniel" \
262 -F "filedescription=Cool text file with cool text inside" \
263 http://www.post.com/postit.cgi
265 So, to send two files in one post you can do it in two ways:
267 1. Send multiple files in a single "field" with a single field name:
269 curl -F "pictures=@dog.gif,cat.gif"
271 2. Send two fields with two field names:
273 curl -F "docpicture=@dog.gif" -F "catpicture=@cat.gif"
277 A HTTP request has the option to include information about which address
278 that referred to actual page, and curl allows the user to specify that
279 referrer to get specified on the command line. It is especially useful to
280 fool or trick stupid servers or CGI scripts that rely on that information
281 being available or contain certain data.
283 curl -e www.coolsite.com http://www.showme.com/
287 A HTTP request has the option to include information about the browser
288 that generated the request. Curl allows it to be specified on the command
289 line. It is especially useful to fool or trick stupid servers or CGI
290 scripts that only accept certain browsers.
294 curl -A 'Mozilla/3.0 (Win95; I)' http://www.nationsbank.com/
296 Other common strings:
297 'Mozilla/3.0 (Win95; I)' Netscape Version 3 for Windows 95
298 'Mozilla/3.04 (Win95; U)' Netscape Version 3 for Windows 95
299 'Mozilla/2.02 (OS/2; U)' Netscape Version 2 for OS/2
300 'Mozilla/4.04 [en] (X11; U; AIX 4.2; Nav)' NS for AIX
301 'Mozilla/4.05 [en] (X11; U; Linux 2.0.32 i586)' NS for Linux
303 Note that Internet Explorer tries hard to be compatible in every way:
304 'Mozilla/4.0 (compatible; MSIE 4.01; Windows 95)' MSIE for W95
306 Mozilla is not the only possible User-Agent name:
307 'Konqueror/1.0' KDE File Manager desktop client
308 'Lynx/2.7.1 libwww-FM/2.14' Lynx command line browser
312 Cookies are generally used by web servers to keep state information at the
313 client's side. The server sets cookies by sending a response line in the
314 headers that looks like 'Set-Cookie: <data>' where the data part then
315 typically contains a set of NAME=VALUE pairs (separated by semicolons ';'
316 like "NAME1=VALUE1; NAME2=VALUE2;"). The server can also specify for what
317 path the "cookie" should be used for (by specifying "path=value"), when the
318 cookie should expire ("expire=DATE"), for what domain to use it
319 ("domain=NAME") and if it should be used on secure connections only
322 If you've received a page from a server that contains a header like:
323 Set-Cookie: sessionid=boo123; path="/foo";
325 it means the server wants that first pair passed on when we get anything in
326 a path beginning with "/foo".
328 Example, get a page that wants my name passed in a cookie:
330 curl -b "name=Daniel" www.sillypage.com
332 Curl also has the ability to use previously received cookies in following
333 sessions. If you get cookies from a server and store them in a file in a
336 curl --dump-header headers www.example.com
338 ... you can then in a second connect to that (or another) site, use the
339 cookies from the 'headers' file like:
341 curl -b headers www.example.com
343 Note that by specifying -b you enable the "cookie awareness" and with -L
344 you can make curl follow a location: (which often is used in combination
345 with cookies). So that if a site sends cookies and a location, you can
346 use a non-existing file to trig the cookie awareness like:
348 curl -L -b empty-file www.example.com
350 The file to read cookies from must be formatted using plain HTTP headers OR
351 as netscape's cookie file. Curl will determine what kind it is based on the
356 The progress meter exists to show a user that something actually is
357 happening. The different fields in the output have the following meaning:
359 % Total % Received % Xferd Average Speed Time Curr.
360 Dload Upload Total Current Left Speed
361 0 151M 0 38608 0 0 9406 0 4:41:43 0:00:04 4:41:39 9287
364 % - percentage completed of the whole transfer
365 Total - total size of the whole expected transfer
366 % - percentage completed of the download
367 Received - currently downloaded amount of bytes
368 % - percentage completed of the upload
369 Xferd - currently uploaded amount of bytes
371 Dload - the average transfer speed of the download
373 Upload - the average transfer speed of the upload
374 Time Total - expected time to complete the operation
375 Time Current - time passed since the invoke
376 Time Left - expected time left to completetion
377 Curr.Speed - the average transfer speed the last 5 seconds (the first
378 5 seconds of a transfer is based on less time of course.)
380 The -# option will display a totally different progress bar that doesn't
381 need much explanation!
385 Curl offers the user to set conditions regarding transfer speed that must
386 be met to let the transfer keep going. By using the switch -y and -Y you
387 can make curl abort transfers if the transfer speed doesn't exceed your
388 given lowest limit for a specified time.
390 To let curl abandon downloading this page if its slower than 3000 bytes per
391 second for 1 minute, run:
393 curl -y 3000 -Y 60 www.far-away-site.com
395 This can very well be used in combination with the overall time limit, so
396 that the above operatioin must be completed in whole within 30 minutes:
398 curl -m 1800 -y 3000 -Y 60 www.far-away-site.com
402 Curl automatically tries to read the .curlrc file (or _curlrc file on win32
403 systems) from the user's home dir on startup.
405 The config file could be made up with normal command line switches, but you
406 can also specify the long options without the dashes to make it more
407 readable. You can separate the options and the parameter with spaces, or
408 with = or :. Comments can be used within the file. If the first letter on a
409 line is a '#'-letter the rest of the line is treated as a comment.
411 If you want the parameter to contain spaces, you must inclose the entire
412 parameter within double quotes ("). Within those quotes, you specify a
415 NOTE: You must specify options and their arguments on the same line.
417 Example, set default time out and proxy in a config file:
419 # We want a 30 minute timeout:
421 # ... and we use a proxy for all accesses:
422 proxy = proxy.our.domain.com:8080
424 White spaces ARE significant at the end of lines, but all white spaces
425 leading up to the first characters of each line are ignored.
427 Prevent curl from reading the default file by using -q as the first command
428 line parameter, like:
430 curl -q www.thatsite.com
432 Force curl to get and display a local help page in case it is invoked
433 without URL by making a config file similar to:
436 url = "http://help.with.curl.com/curlhelp.html"
438 You can specify another config file to be read by using the -K/--config
439 flag. If you set config file name to "-" it'll read the config from stdin,
440 which can be handy if you want to hide options from being visible in process
443 echo "user = user:passwd" | curl -K - http://that.secret.site.com
447 When using curl in your own very special programs, you may end up needing
448 to pass on your own custom headers when getting a web page. You can do
449 this by using the -H flag.
451 Example, send the header "X-you-and-me: yes" to the server when getting a
454 curl -H "X-you-and-me: yes" www.love.com
456 This can also be useful in case you want curl to send a different text in
457 a header than it normally does. The -H header you specify then replaces the
458 header curl would normally send.
462 Do note that when getting files with the ftp:// URL, the given path is
463 relative the directory you enter. To get the file 'README' from your home
464 directory at your ftp site, do:
466 curl ftp://user:passwd@my.site.com/README
468 But if you want the README file from the root directory of that very same
469 site, you need to specify the absolute file name:
471 curl ftp://user:passwd@my.site.com//README
473 (I.e with an extra slash in front of the file name.)
477 The FTP protocol requires one of the involved parties to open a second
478 connction as soon as data is about to get transfered. There are two ways to
481 The default way for curl is to issue the PASV command which causes the
482 server to open another port and await another connection performed by the
483 client. This is good if the client is behind a firewall that don't allow
484 incoming connections.
486 curl ftp.download.com
488 If the server for example, is behind a firewall that don't allow connections
489 on other ports than 21 (or if it just doesn't support the PASV command), the
490 other way to do it is to use the PORT command and instruct the server to
491 connect to the client on the given (as parameters to the PORT command) IP
494 The -P flag to curl supports a few different options. Your machine may have
495 several IP-addresses and/or network interfaces and curl allows you to select
496 which of them to use. Default address can also be used:
498 curl -P - ftp.download.com
500 Download with PORT but use the IP address of our 'le0' interface (this does
501 not work on windows):
503 curl -P le0 ftp.download.com
505 Download with PORT but use 192.168.0.10 as our IP address to use:
507 curl -P 192.168.0.10 ftp.download.com
511 Get a web page from a server using a specified port for the interface:
513 curl --interface eth0:1 http://www.netscape.com/
517 curl --interface 192.168.1.10 http://www.netscape.com/
521 Secure HTTP requires SSL libraries to be installed and used when curl is
522 built. If that is done, curl is capable of retrieving and posting documents
523 using the HTTPS procotol.
527 curl https://www.secure-site.com
529 Curl is also capable of using your personal certificates to get/post files
530 from sites that require valid certificates. The only drawback is that the
531 certificate needs to be in PEM-format. PEM is a standard and open format to
532 store certificates with, but it is not used by the most commonly used
533 browsers (Netscape and MSEI both use the so called PKCS#12 format). If you
534 want curl to use the certificates you use with your (favourite) browser, you
535 may need to download/compile a converter that can convert your browser's
536 formatted certificates to PEM formatted ones. This kind of converter is
537 included in recent versions of OpenSSL, and for older versions Dr Stephen
538 N. Henson has written a patch for SSLeay that adds this functionality. You
539 can get his patch (that requires an SSLeay installation) from his site at:
540 http://www.drh-consultancy.demon.co.uk/
542 Example on how to automatically retrieve a document using a certificate with
545 curl -E /path/to/cert.pem:password https://secure.site.com/
547 If you neglect to specify the password on the command line, you will be
548 prompted for the correct password before any data can be received.
550 Many older SSL-servers have problems with SSLv3 or TLS, that newer versions
551 of OpenSSL etc is using, therefore it is sometimes useful to specify what
552 SSL-version curl should use. Use -3 or -2 to specify that exact SSL version
555 curl -2 https://secure.site.com/
557 Otherwise, curl will first attempt to use v3 and then v2.
559 To use OpenSSL to convert your favourite browser's certificate into a PEM
560 formatted one that curl can use, do something like this (assuming netscape,
561 but IE is likely to work similarly):
563 You start with hitting the 'security' menu button in netscape.
565 Select 'certificates->yours' and then pick a certificate in the list
567 Press the 'export' button
569 enter your PIN code for the certs
571 select a proper place to save it
573 Run the 'openssl' application to convert the certificate. If you cd to the
574 openssl installation, you can do it like:
576 # ./apps/openssl pkcs12 -certfile [file you saved] -out [PEMfile]
579 RESUMING FILE TRANSFERS
581 To continue a file transfer where it was previously aborted, curl supports
582 resume on http(s) downloads as well as ftp uploads and downloads.
584 Continue downloading a document:
586 curl -c -o file ftp://ftp.server.com/path/file
588 Continue uploading a document(*1):
590 curl -c -T file ftp://ftp.server.com/path/file
592 Continue downloading a document from a web server(*2):
594 curl -c -o file http://www.server.com/
596 (*1) = This requires that the ftp server supports the non-standard command
597 SIZE. If it doesn't, curl will say so.
599 (*2) = This requires that the wb server supports at least HTTP/1.1. If it
600 doesn't, curl will say so.
604 HTTP allows a client to specify a time condition for the document it
605 requests. It is If-Modified-Since or If-Unmodified-Since. Curl allow you to
606 specify them with the -z/--time-cond flag.
608 For example, you can easily make a download that only gets performed if the
609 remote file is newer than a local copy. It would be made like:
611 curl -z local.html http://remote.server.com/remote.html
613 Or you can download a file only if the local file is newer than the remote
614 one. Do this by prepending the date string with a '-', as in:
616 curl -z -local.html http://remote.server.com/remote.html
618 You can specify a "free text" date as condition. Tell curl to only download
619 the file if it was updated since yesterday:
621 curl -z yesterday http://remote.server.com/remote.html
623 Curl will then accept a wide range of date formats. You always make the date
624 check the other way around by prepending it with a dash '-'.
630 curl dict://dict.org/m:curl
631 curl dict://dict.org/d:heisenbug:jargon
632 curl dict://dict.org/d:daniel:web1913
634 Aliases for 'm' are 'match' and 'find', and aliases for 'd' are 'define'
635 and 'lookup'. For example,
637 curl dict://dict.org/find:curl
639 Commands that break the URL description of the RFC (but not the DICT
642 curl dict://dict.org/show:db
643 curl dict://dict.org/show:strat
645 Authentication is still missing (but this is not required by the RFC)
649 If you have installed the OpenLDAP library, curl can take advantage of it
650 and offer ldap:// support.
652 LDAP is a complex thing and writing an LDAP query is not an easy task. I do
653 advice you to dig up the syntax description for that elsewhere, RFC 1959 if
654 no other place is better.
656 To show you an example, this is now I can get all people from my local LDAP
657 server that has a certain sub-domain in their email address:
659 curl -B "ldap://ldap.frontec.se/o=frontec??sub?mail=*sth.frontec.se"
661 If I want the same info in HTML format, I can get it by not using the -B
662 (enforce ASCII) flag.
664 ENVIRONMENT VARIABLES
666 Curl reads and understands the following environment variables:
668 HTTP_PROXY, HTTPS_PROXY, FTP_PROXY, GOPHER_PROXY
670 They should be set for protocol-specific proxies. General proxy should be
675 A comma-separated list of host names that shouldn't go through any proxy is
676 set in (only an asterisk, '*' matches all hosts)
680 If a tail substring of the domain-path for a host matches one of these
681 strings, transactions with that node will not be proxied.
684 The usage of the -x/--proxy flag overrides the environment variables.
688 Unix introduced the .netrc concept a long time ago. It is a way for a user
689 to specify name and password for commonly visited ftp sites in a file so
690 that you don't have to type them in each time you visit those sites. You
691 realize this is a big security risk if someone else gets hold of your
692 passwords, so therefor most unix programs won't read this file unless it is
693 only readable by yourself (curl doesn't care though).
695 Curl supports .netrc files if told so (using the -n/--netrc option). This is
696 not restricted to only ftp, but curl can use it for all protocols where
697 authentication is used.
699 A very simple .netrc file could look something like:
701 machine curl.haxx.se login iamdaniel password mysecret
705 To better allow script programmers to get to know about the progress of
706 curl, the -w/--write-out option was introduced. Using this, you can specify
707 what information from the previous transfer you want to extract.
709 To display the amount of bytes downloaded together with some text and an
712 curl -w 'We downloaded %{size_download} bytes\n' www.download.com
714 KERBEROS4 FTP TRANSFER
716 Curl supports kerberos4 for FTP transfers. You need the kerberos package
717 installed and used at curl build time for it to be used.
719 First, get the krb-ticket the normal way, like with the kauth tool. Then use
720 curl in way similar to:
722 curl --krb4 private ftp://krb4site.com -u username:fakepwd
724 There's no use for a password on the -u switch, but a blank one will make
725 curl ask for one and you already entered the real password to kauth.
729 We have an open mailing list to discuss curl, its development and things
732 To subscribe, mail curl-request@contactor.se with "subscribe <fill in your
733 email address>" in the body.
735 To post to the list, mail curl@contactor.se.
737 To unsubcribe, mail curl-request@contactor.se with "unsubscribe <your
738 subscribed email address>" in the body.