1CURLOPT_URL(3) curl_easy_setopt options CURLOPT_URL(3)
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6 CURLOPT_URL - provide the URL to use in the request
7
9 #include <curl/curl.h>
10 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_URL, char *URL);
12
14 Pass in a pointer to the URL to work with. The parameter should be a
15 char * to a null-terminated string which must be URL-encoded in the
16 following format:
17 scheme://host:port/path
19 For a greater explanation of the format please see RFC3986.
21 libcurl doesn't validate the syntax or use this variable until the
23 transfer is issued. Even if you set a crazy value here,
24 curl_easy_setopt(3) will still return CURLE_OK.
25 If the given URL is missing a scheme name (such as "http://" or
27 "ftp://" etc) then libcurl will make a guess based on the host. If the
28 outermost sub-domain name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP
29 then that protocol will be used, otherwise HTTP will be used. Since
30 7.45.0 guessing can be disabled by setting a default protocol, see CUR‐
31 LOPT_DEFAULT_PROTOCOL(3) for details.
32 Should the protocol, either that specified by the scheme or deduced by
34 libcurl from the host name, not be supported by libcurl then
35 CURLE_UNSUPPORTED_PROTOCOL will be returned from either the
36 curl_easy_perform(3) or curl_multi_perform(3) functions when you call
37 them. Use curl_version_info(3) for detailed information of which proto‐
38 cols are supported by the build of libcurl you are using.
39 CURLOPT_PROTOCOLS(3) can be used to limit what protocols libcurl will
41 use for this transfer, independent of what libcurl has been compiled to
42 support. That may be useful if you accept the URL from an external
43 source and want to limit the accessibility.
44 The CURLOPT_URL(3) string will be ignored if CURLOPT_CURLU(3) is set.
46 CURLOPT_URL(3) or CURLOPT_CURLU(3) must be set before a transfer is
48 started.
49 The host part of the URL contains the address of the server that you
51 want to connect to. This can be the fully qualified domain name of the
52 server, the local network name of the machine on your network or the IP
53 address of the server or machine represented by either an IPv4 or IPv6
54 address. For example:
55 http://www.example.com/
57 http://hostname/
59 http://192.168.0.1/
61 http://[2001:1890:1112:1::20]/
63 It is also possible to specify the user name, password and any sup‐
65 ported login options as part of the host, for the following protocols,
66 when connecting to servers that require authentication:
67 http://user:password@www.example.com
69 ftp://user:password@ftp.example.com
71 smb://domain%2fuser:password@server.example.com
73 imap://user:password;options@mail.example.com
75 pop3://user:password;options@mail.example.com
77 smtp://user:password;options@mail.example.com
79 At present only IMAP, POP3 and SMTP support login options as part of
81 the host. For more information about the login options in URL syntax
82 please see RFC2384, RFC5092 and IETF draft draft-earhart-url-
83 smtp-00.txt (Added in 7.31.0).
84 The port is optional and when not specified libcurl will use the
86 default port based on the determined or specified protocol: 80 for
87 HTTP, 21 for FTP and 25 for SMTP, etc. The following examples show how
88 to specify the port:
89 http://www.example.com:8080/ - This will connect to a web server using
91 port 8080 rather than 80.
92 smtp://mail.example.com:587/ - This will connect to a SMTP server on
94 the alternative mail port.
95 The path part of the URL is protocol specific and whilst some examples
97 are given below this list is not conclusive:
98 HTTP The path part of an HTTP request specifies the file to retrieve
101 and from what directory. If the directory is not specified then
102 the web server's root directory is used. If the file is omitted
103 then the default document will be retrieved for either the
104 directory specified or the root directory. The exact resource
105 returned for each URL is entirely dependent on the server's con‐
106 figuration.
107 http://www.example.com - This gets the main page from the web
109 server.
110 http://www.example.com/index.html - This returns the main page
112 by explicitly requesting it.
113 http://www.example.com/contactus/ - This returns the default
115 document from the contactus directory.
116 FTP The path part of an FTP request specifies the file to retrieve
119 and from what directory. If the file part is omitted then
120 libcurl downloads the directory listing for the directory speci‐
121 fied. If the directory is omitted then the directory listing for
122 the root / home directory will be returned.
123 ftp://ftp.example.com - This retrieves the directory listing for
125 the root directory.
126 ftp://ftp.example.com/readme.txt - This downloads the file
128 readme.txt from the root directory.
129 ftp://ftp.example.com/libcurl/readme.txt - This downloads
131 readme.txt from the libcurl directory.
132 ftp://user:password@ftp.example.com/readme.txt - This retrieves
134 the readme.txt file from the user's home directory. When a user‐
135 name and password is specified, everything that is specified in
136 the path part is relative to the user's home directory. To
137 retrieve files from the root directory or a directory underneath
138 the root directory then the absolute path must be specified by
139 prepending an additional forward slash to the beginning of the
140 path.
141 ftp://user:password@ftp.example.com//readme.txt - This retrieves
143 the readme.txt from the root directory when logging in as a
144 specified user.
145 FILE When a FILE:// URL is accessed on Windows systems, it can be
148 crafted in a way so that Windows attempts to connect to a
149 (remote) machine when curl wants to read or write such a path.
150 SMTP The path part of a SMTP request specifies the host name to
152 present during communication with the mail server. If the path
153 is omitted then libcurl will attempt to resolve the local com‐
154 puter's host name. However, this may not return the fully quali‐
155 fied domain name that is required by some mail servers and spec‐
156 ifying this path allows you to set an alternative name, such as
157 your machine's fully qualified domain name, which you might have
158 obtained from an external function such as gethostname or getad‐
159 drinfo.
160 smtp://mail.example.com - This connects to the mail server at
162 example.com and sends your local computer's host name in the
163 HELO / EHLO command.
164 smtp://mail.example.com/client.example.com - This will send
166 client.example.com in the HELO / EHLO command to the mail server
167 at example.com.
168 POP3 The path part of a POP3 request specifies the message ID to
171 retrieve. If the ID is not specified then a list of waiting mes‐
172 sages is returned instead.
173 pop3://user:password@mail.example.com - This lists the available
175 messages for the user
176 pop3://user:password@mail.example.com/1 - This retrieves the
178 first message for the user
179 IMAP The path part of an IMAP request not only specifies the mailbox
182 to list (Added in 7.30.0) or select, but can also be used to
183 check the UIDVALIDITY of the mailbox, to specify the UID, SEC‐
184 TION (Added in 7.30.0) and PARTIAL octets (Added in 7.37.0) of
185 the message to fetch and to specify what messages to search for
186 (Added in 7.37.0).
187 imap://user:password@mail.example.com - Performs a top level
189 folder list
190 imap://user:password@mail.example.com/INBOX - Performs a folder
192 list on the user's inbox
193 imap://user:password@mail.example.com/INBOX/;UID=1 - Selects the
195 user's inbox and fetches message with uid = 1
196 imap://user:password@mail.example.com/INBOX/;MAILINDEX=1 -
198 Selects the user's inbox and fetches the first message in the
199 mail box
200 imap://user:password@mail.example.com/INBOX;UIDVALID‐
202 ITY=50/;UID=2 - Selects the user's inbox, checks the UIDVALIDITY
203 of the mailbox is 50 and fetches message 2 if it is
204 imap://user:password@mail.example.com/INBOX/;UID=3/;SECTION=TEXT
206 - Selects the user's inbox and fetches the text portion of mes‐
207 sage 3
208 imap://user:password@mail.example.com/INBOX/;UID=4/;PAR‐
210 TIAL=0.1024 - Selects the user's inbox and fetches the first
211 1024 octets of message 4
212 imap://user:password@mail.example.com/INBOX?NEW - Selects the
214 user's inbox and checks for NEW messages
215 imap://user:password@mail.example.com/INBOX?SUBJECT%20shadows -
217 Selects the user's inbox and searches for messages containing
218 "shadows" in the subject line
219 For more information about the individual components of an IMAP
221 URL please see RFC5092.
222 SCP The path part of a SCP request specifies the file to retrieve
225 and from what directory. The file part may not be omitted. The
226 file is taken as an absolute path from the root directory on the
227 server. To specify a path relative to the user's home directory
228 on the server, prepend ~/ to the path portion. If the user name
229 is not embedded in the URL, it can be set with the CURLOPT_USER‐
230 PWD(3) or CURLOPT_USERNAME(3) option.
231 scp://user@example.com/etc/issue - This specifies the file
233 /etc/issue
234 scp://example.com/~/my-file - This specifies the file my-file in
236 the user's home directory on the server
237 SFTP The path part of a SFTP request specifies the file to retrieve
239 and from what directory. If the file part is omitted then
240 libcurl downloads the directory listing for the directory speci‐
241 fied. If the path ends in a / then a directory listing is
242 returned instead of a file. If the path is omitted entirely
243 then the directory listing for the root / home directory will be
244 returned. If the user name is not embedded in the URL, it can
245 be set with the CURLOPT_USERPWD(3) or CURLOPT_USERNAME(3)
246 option.
247 sftp://user:password@example.com/etc/issue - This specifies the
249 file /etc/issue
250 sftp://user@example.com/~/my-file - This specifies the file my-
252 file in the user's home directory
253 sftp://ssh.example.com/~/Documents/ - This requests a directory
255 listing of the Documents directory under the user's home direc‐
256 tory
257 SMB The path part of a SMB request specifies the file to retrieve
260 and from what share and directory or the share to upload to and
261 as such, may not be omitted. If the user name is not embedded
262 in the URL, it can be set with the CURLOPT_USERPWD(3) or CUR‐
263 LOPT_USERNAME(3) option. If the user name is embedded in the URL
264 then it must contain the domain name and as such, the backslash
265 must be URL encoded as %2f.
266 smb://server.example.com/files/issue - This specifies the file
268 "issue" located in the root of the "files" share
269 smb://server.example.com/files/ -T issue - This specifies the
271 file "issue" will be uploaded to the root of the "files" share.
272 curl supports SMB version 1 (only)
274 LDAP The path part of a LDAP request can be used to specify the: Dis‐
276 tinguished Name, Attributes, Scope, Filter and Extension for a
277 LDAP search. Each field is separated by a question mark and when
278 that field is not required an empty string with the question
279 mark separator should be included.
280 ldap://ldap.example.com/o=My%20Organisation - This will perform
282 a LDAP search with the DN as My Organisation.
283 ldap://ldap.example.com/o=My%20Organisation?postalAddress - This
285 will perform the same search but will only return postalAddress
286 attributes.
287 ldap://ldap.example.com/?rootDomainNamingContext - This speci‐
289 fies an empty DN and requests information about the rootDomain‐
290 NamingContext attribute for an Active Directory server.
291 For more information about the individual components of a LDAP
293 URL please see RFC4516.
294 RTMP There's no official URL spec for RTMP so libcurl uses the URL
296 syntax supported by the underlying librtmp library. It has a
297 syntax where it wants a traditional URL, followed by a space and
298 a series of space-separated name=value pairs.
299 While space is not typically a "legal" letter, libcurl accepts
301 them. When a user wants to pass in a '#' (hash) character it
302 will be treated as a fragment and get cut off by libcurl if pro‐
303 vided literally. You will instead have to escape it by providing
304 it as backslash and its ASCII value in hexadecimal: "\23".
305 The application does not have to keep the string around after setting
307 this option.
308
310 The string pointed to in the CURLOPT_URL(3) argument is generally
311 expected to be a sequence of characters using an ASCII compatible
312 encoding.
313 If libcurl is built with IDN support, the server name part of the URL
315 can use an "international name" by using the current encoding (accord‐
316 ing to locale) or UTF-8 (when winidn is used).
317 If libcurl is built without IDN support, the server name is used
319 exactly as specified when passed to the name resolver functions.
320
322 There is no default URL. If this option isn't set, no transfer can be
323 performed.
324
326 Applications may at times find it convenient to allow users to specify
327 URLs for various purposes and that string would then end up fed to this
328 option.
329 Getting a URL from an external untrusted party will bring reasons for
331 several security concerns:
332 If you have an application that runs as or in a server application,
334 getting an unfiltered URL can easily trick your application to access a
335 local resource instead of a remote. Protecting yourself against local‐
336 host accesses is very hard when accepting user provided URLs.
337 Such custom URLs can also access other ports than you planned as port
339 numbers are part of the regular URL format. The combination of a local
340 host and a custom port number can allow external users to play tricks
341 with your local services.
342 Accepting external URLs may also use other protocols than http:// or
344 other common ones. Restrict what accept with CURLOPT_PROTOCOLS(3).
345 User provided URLs can also be made to point to sites that redirect
347 further on (possibly to other protocols too). Consider your CUR‐
348 LOPT_FOLLOWLOCATION(3) and CURLOPT_REDIR_PROTOCOLS(3) settings.
349
351 All
352
354 CURL *curl = curl_easy_init();
355 if(curl) {
356 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
357 curl_easy_perform(curl);
359 }
360
362 POP3 and SMTP were added in 7.31.0
363
365 Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insuf‐
366 ficient heap space.
367 Note that curl_easy_setopt(3) won't actually parse the given string so
369 given a bad URL, it will not be detected until curl_easy_perform(3) or
370 similar is called.
371
373 CURLOPT_VERBOSE(3), CURLOPT_PROTOCOLS(3), CURLOPT_FORBID_REUSE(3), CUR‐
374 LOPT_FRESH_CONNECT(3), curl_easy_perform(3), CURLINFO_REDIRECT_URL(3),
375 CURLOPT_PATH_AS_IS(3), CURLOPT_CURLU(3),
376libcurl 7.71.1 June 25, 2020 CURLOPT_URL(3)