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23 .TH CURLOPT_URL 3 "17 Jun 2014" "libcurl 7.37.0" "curl_easy_setopt options"
25 CURLOPT_URL \- provide the URL to use in the request
27 #include <curl/curl.h>
29 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_URL, char *URL);
31 Pass in a pointer to the \fIURL\fP to work with. The parameter should be a
32 char * to a zero terminated string which must be URL-encoded in the following
35 scheme://host:port/path
37 For a greater explanation of the format please see RFC3986.
39 libcurl doesn't validate the syntax or use this variable until the transfer is
40 issued. Even if you set a crazy value here, \fIcurl_easy_setopt(3)\fP will
41 still return \fICURLE_OK\fP.
43 If the given URL is missing a scheme name (such as "http://" or "ftp://" etc)
44 then libcurl will make a guess based on the host. If the outermost sub-domain
45 name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP then that protocol will be
46 used, otherwise HTTP will be used. Since 7.45.0 guessing can be disabled by
47 setting a default protocol, see \fICURLOPT_DEFAULT_PROTOCOL(3)\fP for details.
49 Should the protocol, either that specified by the scheme or deduced by libcurl
50 from the host name, not be supported by libcurl then
51 \fICURLE_UNSUPPORTED_PROTOCOL\fP will be returned from either the
52 \fIcurl_easy_perform(3)\fP or \fIcurl_multi_perform(3)\fP functions when you
53 call them. Use \fIcurl_version_info(3)\fP for detailed information of which
54 protocols are supported by the build of libcurl you are using.
56 \fICURLOPT_PROTOCOLS(3)\fP can be used to limit what protocols libcurl will
57 use for this transfer, independent of what libcurl has been compiled to
58 support. That may be useful if you accept the URL from an external source and
59 want to limit the accessibility.
61 \fICURLOPT_URL(3)\fP is the only option that \fBmust\fP be set before a
64 The host part of the URL contains the address of the server that you want to
65 connect to. This can be the fully qualified domain name of the server, the
66 local network name of the machine on your network or the IP address of the
67 server or machine represented by either an IPv4 or IPv6 address. For example:
69 http://www.example.com/
75 http://[2001:1890:1112:1::20]/
77 It is also possible to specify the user name, password and any supported login
78 options as part of the host, for the following protocols, when connecting to
79 servers that require authentication:
81 http://user:password@www.example.com
83 ftp://user:password@ftp.example.com
85 smb://domain%2fuser:password@server.example.com
87 imap://user:password;options@mail.example.com
89 pop3://user:password;options@mail.example.com
91 smtp://user:password;options@mail.example.com
93 At present only IMAP, POP3 and SMTP support login options as part of the host.
94 For more information about the login options in URL syntax please see RFC2384,
95 RFC5092 and IETF draft draft-earhart-url-smtp-00.txt (Added in 7.31.0).
97 The port is optional and when not specified libcurl will use the default port
98 based on the determined or specified protocol: 80 for HTTP, 21 for FTP and 25
99 for SMTP, etc. The following examples show how to specify the port:
101 http://www.example.com:8080/ - This will connect to a web server using port
104 smtp://mail.example.com:587/ - This will connect to a SMTP server on the
105 alternative mail port.
107 The path part of the URL is protocol specific and whilst some examples are
108 given below this list is not conclusive:
111 The path part of a HTTP request specifies the file to retrieve and from what
112 directory. If the directory is not specified then the web server's root
113 directory is used. If the file is omitted then the default document will be
114 retrieved for either the directory specified or the root directory. The exact
115 resource returned for each URL is entirely dependent on the server's
118 http://www.example.com - This gets the main page from the web server.
120 http://www.example.com/index.html - This returns the main page by explicitly
123 http://www.example.com/contactus/ - This returns the default document from
124 the contactus directory.
127 The path part of an FTP request specifies the file to retrieve and from what
128 directory. If the file part is omitted then libcurl downloads the directory
129 listing for the directory specified. If the directory is omitted then
130 the directory listing for the root / home directory will be returned.
132 ftp://ftp.example.com - This retrieves the directory listing for the root
135 ftp://ftp.example.com/readme.txt - This downloads the file readme.txt from the
138 ftp://ftp.example.com/libcurl/readme.txt - This downloads readme.txt from the
141 ftp://user:password@ftp.example.com/readme.txt - This retrieves the readme.txt
142 file from the user's home directory. When a username and password is
143 specified, everything that is specified in the path part is relative to the
144 user's home directory. To retrieve files from the root directory or a
145 directory underneath the root directory then the absolute path must be
146 specified by prepending an additional forward slash to the beginning of the
149 ftp://user:password@ftp.example.com//readme.txt - This retrieves the readme.txt
150 from the root directory when logging in as a specified user.
153 The path part of a SMTP request specifies the host name to present during
154 communication with the mail server. If the path is omitted then libcurl will
155 attempt to resolve the local computer's host name. However, this may not
156 return the fully qualified domain name that is required by some mail servers
157 and specifying this path allows you to set an alternative name, such as
158 your machine's fully qualified domain name, which you might have obtained
159 from an external function such as gethostname or getaddrinfo.
161 smtp://mail.example.com - This connects to the mail server at example.com and
162 sends your local computer's host name in the HELO / EHLO command.
164 smtp://mail.example.com/client.example.com - This will send client.example.com in
165 the HELO / EHLO command to the mail server at example.com.
168 The path part of a POP3 request specifies the message ID to retrieve. If the
169 ID is not specified then a list of waiting messages is returned instead.
171 pop3://user:password@mail.example.com - This lists the available messages for
174 pop3://user:password@mail.example.com/1 - This retrieves the first message for
178 The path part of an IMAP request not only specifies the mailbox to list (Added
179 in 7.30.0) or select, but can also be used to check the UIDVALIDITY of the
180 mailbox, to specify the UID, SECTION (Added in 7.30.0) and PARTIAL octets
181 (Added in 7.37.0) of the message to fetch and to specify what messages to
182 search for (Added in 7.37.0).
184 imap://user:password@mail.example.com - Performs a top level folder list
186 imap://user:password@mail.example.com/INBOX - Performs a folder list on the
189 imap://user:password@mail.example.com/INBOX/;UID=1 - Selects the user's inbox
190 and fetches message 1
192 imap://user:password@mail.example.com/INBOX;UIDVALIDITY=50/;UID=2 - Selects
193 the user's inbox, checks the UIDVALIDITY of the mailbox is 50 and fetches
196 imap://user:password@mail.example.com/INBOX/;UID=3/;SECTION=TEXT - Selects the
197 user's inbox and fetches the text portion of message 3
199 imap://user:password@mail.example.com/INBOX/;UID=4/;PARTIAL=0.1024 - Selects
200 the user's inbox and fetches the first 1024 octets of message 4
202 imap://user:password@mail.example.com/INBOX?NEW - Selects the user's inbox and
203 checks for NEW messages
205 imap://user:password@mail.example.com/INBOX?SUBJECT%20shadows - Selects the
206 user's inbox and searches for messages containing "shadows" in the subject
209 For more information about the individual components of an IMAP URL please
213 The path part of a SCP request specifies the file to retrieve and from what
214 directory. The file part may not be omitted. The file is taken as an absolute
215 path from the root directory on the server. To specify a path relative to the
216 user's home directory on the server, prepend ~/ to the path portion. If the
217 user name is not embedded in the URL, it can be set with the
218 \fICURLOPT_USERPWD(3)\fP or \fICURLOPT_USERNAME(3)\fP option.
220 scp://user@example.com/etc/issue - This specifies the file /etc/issue
222 scp://example.com/~/my-file - This specifies the file my-file in the
223 user's home directory on the server
226 The path part of a SFTP request specifies the file to retrieve and from what
227 directory. If the file part is omitted then libcurl downloads the directory
228 listing for the directory specified. If the path ends in a / then a directory
229 listing is returned instead of a file. If the path is omitted entirely then
230 the directory listing for the root / home directory will be returned. If the
231 user name is not embedded in the URL, it can be set with the
232 \fICURLOPT_USERPWD(3)\fP or \fICURLOPT_USERNAME(3)\fP option.
234 sftp://user:password@example.com/etc/issue - This specifies the file
237 sftp://user@example.com/~/my-file - This specifies the file my-file in the
238 user's home directory
240 sftp://ssh.example.com/~/Documents/ - This requests a directory listing
241 of the Documents directory under the user's home directory
244 The path part of a SMB request specifies the file to retrieve and from what
245 share and directory or the share to upload to and as such, may not be omitted.
246 If the user name is not embedded in the URL, it can be set with the
247 \fICURLOPT_USERPWD(3)\fP or \fICURLOPT_USERNAME(3)\fP option. If the user name
248 is embedded in the URL then it must contain the domain name and as such, the
249 backslash must be URL encoded as %2f.
251 smb://server.example.com/files/issue - This specifies the file "issue" located
252 in the root of the "files" share
254 smb://server.example.com/files/ -T issue - This specifies the file "issue" will
255 be uploaded to the root of the "files" share.
258 The path part of a LDAP request can be used to specify the: Distinguished
259 Name, Attributes, Scope, Filter and Extension for a LDAP search. Each field
260 is separated by a question mark and when that field is not required an empty
261 string with the question mark separator should be included.
263 ldap://ldap.example.com/o=My%20Organisation - This will perform a LDAP search
264 with the DN as My Organisation.
266 ldap://ldap.example.com/o=My%20Organisation?postalAddress - This will perform
267 the same search but will only return postalAddress attributes.
269 ldap://ldap.example.com/?rootDomainNamingContext - This specifies an empty DN
270 and requests information about the rootDomainNamingContext attribute for an
271 Active Directory server.
273 For more information about the individual components of a LDAP URL please
276 There's no official URL spec for RTMP so libcurl uses the URL syntax supported
277 by the underlying librtmp library. It has a syntax where it wants a
278 traditional URL, followed by a space and a series of space-separated
281 While space is not typically a "legal" letter, libcurl accepts them. When a
282 user wants to pass in a '#' (hash) character it will be treated as a fragment
283 and get cut off by libcurl if provided literally. You will instead have to
284 escape it by providing it as backslash and its ASCII value in hexadecimal:
287 There is no default URL. If this option isn't set, no transfer can be
289 .SH SECURITY CONCERNS
290 Applications may at times find it convenient to allow users to specify URLs
291 for various purposes and that string would then end up fed to this option.
293 Getting a URL from an external untrusted party will bring reasons for several
296 If you have an application that runs as or in a server application, getting an
297 unfiltered URL can easily trick your application to access a local resource
298 instead of a remote. Protecting yourself against localhost accesses is very
299 hard when accepting user provided URLs.
301 Such custom URLs can also access other ports than you planned as port numbers
302 are part of the regular URL format. The combination of a local host and a
303 custom port number can allow external users to play tricks with your local
306 Accepting external URLs may also use other protocols than http:// or other
307 common ones. Restrict what accept with \fICURLOPT_PROTOCOLS(3)\fP.
309 User provided URLs can also be made to point to sites that redirect further on
310 (possibly to other protocols too). Consider your
311 \fICURLOPT_FOLLOWLOCATION(3)\fP and \fICURLOPT_REDIR_PROTOCOLS(3)\fP settings.
316 CURL *curl = curl_easy_init();
318 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
320 curl_easy_perform(curl);
324 POP3 and SMTP were added in 7.31.0
326 Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient
329 Note that \fIcurl_easy_setopt(3)\fP won't actually parse the given string so
330 given a bad URL, it will not be detected until \fIcurl_easy_perform(3)\fP or
333 .BR CURLOPT_VERBOSE "(3), " CURLOPT_PROTOCOLS "(3), "
334 .BR CURLOPT_FORBID_REUSE "(3), " CURLOPT_FRESH_CONNECT "(3), "
335 .BR curl_easy_perform "(3), "
336 .BR CURLINFO_REDIRECT_URL "(3), " CURLOPT_PATH_AS_IS "(3), "