NAME¶
CURLOPT_URL - provide the URL to use in the request
SYNOPSIS¶
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_URL, char *URL);
DESCRIPTION¶
Pass in a pointer to the
URL to work with. The parameter should be a char
* to a zero terminated string which must be URL-encoded in the following
format:
scheme://host:port/path
For a greater explanation of the format please see RFC3986.
libcurl doesn't validate the syntax or use this variable until the transfer is
issued. Even if you set a crazy value here,
curl_easy_setopt(3) will
still return
CURLE_OK.
If the given URL lacks the scheme (such as "
http://" or
"
ftp://" etc) then libcurl will attempt to resolve the protocol
based on one of the following given host names: HTTP, FTP, DICT, LDAP, IMAP,
POP3 or SMTP
Should the protocol, either that specified by the scheme or deduced by libcurl
from the host name, not be supported by libcurl then
CURLE_UNSUPPORTED_PROTOCOL will be returned from either the
curl_easy_perform(3) or
curl_multi_perform(3) functions when you
call them. Use
curl_version_info(3) for detailed information of which
protocols are supported by the build of libcurl you are using.
CURLOPT_PROTOCOLS(3) can be used to limit what protocols libcurl will use
for this transfer, independent of what libcurl has been compiled to support.
That may be useful if you accept the URL from an external source and want to
limit the accessibility.
CURLOPT_URL(3) is the only option that
must be set before a
transfer is started.
The host part of the URL contains the address of the server that you want to
connect to. This can be the fully qualified domain name of the server, the
local network name of the machine on your network or the IP address of the
server or machine represented by either an IPv4 or IPv6 address. For example:
http://www.example.com/
http://hostname/
http://192.168.0.1/
http://[2001:1890:1112:1::20]/
It is also possible to specify the user name, password and any supported login
options as part of the host, for the following protocols, when connecting to
servers that require authentication:
http://user:password@www.example.com
ftp://user:password@ftp.example.com
imap://user:password;options@mail.example.com
pop3://user:password;options@mail.example.com
smtp://user:password;options@mail.example.com
At present only IMAP, POP3 and SMTP support login options as part of the host.
For more information about the login options in URL syntax please see RFC2384,
RFC5092 and IETF draft draft-earhart-url-smtp-00.txt (Added in 7.31.0).
The port is optional and when not specified libcurl will use the default port
based on the determined or specified protocol: 80 for HTTP, 21 for FTP and 25
for SMTP, etc. The following examples show how to specify the port:
http://www.example.com:8080/ - This will connect to a web server using port 8080
rather than 80.
smtp://mail.example.com:587/ - This will connect to a SMTP server on the
alternative mail port.
The path part of the URL is protocol specific and whilst some examples are given
below this list is not conclusive:
- HTTP
- The path part of a HTTP request specifies the file to retrieve and from
what directory. If the directory is not specified then the web server's
root directory is used. If the file is omitted then the default document
will be retrieved for either the directory specified or the root
directory. The exact resource returned for each URL is entirely dependent
on the server's configuration.
http://www.example.com - This gets the main page from the web server.
http://www.example.com/index.html - This returns the main page by explicitly
requesting it.
http://www.example.com/contactus/ - This returns the default document from
the contactus directory.
- FTP
- The path part of an FTP request specifies the file to retrieve and from
what directory. If the file part is omitted then libcurl downloads the
directory listing for the directory specified. If the directory is omitted
then the directory listing for the root / home directory will be returned.
ftp://ftp.example.com - This retrieves the directory listing for the root
directory.
ftp://ftp.example.com/readme.txt - This downloads the file readme.txt from
the root directory.
ftp://ftp.example.com/libcurl/readme.txt - This downloads readme.txt from
the libcurl directory.
ftp://user:password@ftp.example.com/readme.txt - This retrieves the
readme.txt file from the user's home directory. When a username and
password is specified, everything that is specified in the path part is
relative to the user's home directory. To retrieve files from the root
directory or a directory underneath the root directory then the absolute
path must be specified by prepending an additional forward slash to the
beginning of the path.
ftp://user:password@ftp.example.com//readme.txt - This retrieves the
readme.txt from the root directory when logging in as a specified user.
- SMTP
- The path part of a SMTP request specifies the host name to present during
communication with the mail server. If the path is omitted then libcurl
will attempt to resolve the local computer's host name. However, this may
not return the fully qualified domain name that is required by some mail
servers and specifying this path allows you to set an alternative name,
such as your machine's fully qualified domain name, which you might have
obtained from an external function such as gethostname or getaddrinfo.
smtp://mail.example.com - This connects to the mail server at example.com
and sends your local computer's host name in the HELO / EHLO command.
smtp://mail.example.com/client.example.com - This will send
client.example.com in the HELO / EHLO command to the mail server at
example.com.
- POP3
- The path part of a POP3 request specifies the message ID to retrieve. If
the ID is not specified then a list of waiting messages is returned
instead.
pop3://user:password@mail.example.com - This lists the available messages
for the user
pop3://user:password@mail.example.com/1 - This retrieves the first message
for the user
- IMAP
- The path part of an IMAP request not only specifies the mailbox to list
(Added in 7.30.0) or select, but can also be used to check the UIDVALIDITY
of the mailbox, to specify the UID, SECTION (Added in 7.30.0) and PARTIAL
octets (Added in 7.37.0) of the message to fetch and to specify what
messages to search for (Added in 7.37.0).
imap://user:password@mail.example.com - Performs a top level folder list
imap://user:password@mail.example.com/INBOX - Performs a folder list on the
user's inbox
imap://user:password@mail.example.com/INBOX/;UID=1 - Selects the user's
inbox and fetches message 1
imap://user:password@mail.example.com/INBOX;UIDVALIDITY=50/;UID=2 - Selects
the user's inbox, checks the UIDVALIDITY of the mailbox is 50 and fetches
message 2 if it is
imap://user:password@mail.example.com/INBOX/;UID=3/;SECTION=TEXT - Selects
the user's inbox and fetches the text portion of message 3
imap://user:password@mail.example.com/INBOX/;UID=4/;PARTIAL=0.1024 - Selects
the user's inbox and fetches the first 1024 octets of message 4
imap://user:password@mail.example.com/INBOX?NEW - Selects the user's inbox
and checks for NEW messages
imap://user:password@mail.example.com/INBOX?SUBJECT%20shadows - Selects the
user's inbox and searches for messages containing "shadows" in
the subject line
For more information about the individual components of an IMAP URL please
see RFC5092.
- SCP
- The path part of a SCP request specifies the file to retrieve and from
what directory. The file part may not be omitted. The file is taken as an
absolute path from the root directory on the server. To specify a path
relative to the user's home directory on the server, prepend ~/ to the
path portion. If the user name is not embedded in the URL, it can be set
with the CURLOPT_USERPWD(3) or CURLOPT_USERNAME(3) option.
scp://user@example.com/etc/issue - This specifies the file /etc/issue
scp://example.com/~/my-file - This specifies the file my-file in the user's
home directory on the server
- SFTP
- The path part of a SFTP request specifies the file to retrieve and from
what directory. If the file part is omitted then libcurl downloads the
directory listing for the directory specified. If the path ends in a /
then a directory listing is returned instead of a file. If the path is
omitted entirely then the directory listing for the root / home directory
will be returned. If the user name is not embedded in the URL, it can be
set with the CURLOPT_USERPWD(3) or CURLOPT_USERNAME(3)
option.
sftp://user:password@example.com/etc/issue - This specifies the file
/etc/issue
sftp://user@example.com/~/my-file - This specifies the file my-file in the
user's home directory
sftp://ssh.example.com/~/Documents/ - This requests a directory listing of
the Documents directory under the user's home directory
- LDAP
- The path part of a LDAP request can be used to specify the: Distinguished
Name, Attributes, Scope, Filter and Extension for a LDAP search. Each
field is separated by a question mark and when that field is not required
an empty string with the question mark separator should be included.
ldap://ldap.example.com/o=My%20Organisation - This will perform a LDAP
search with the DN as My Organisation.
ldap://ldap.example.com/o=My%20Organisation?postalAddress - This will
perform the same search but will only return postalAddress attributes.
ldap://ldap.example.com/?rootDomainNamingContext - This specifies an empty
DN and requests information about the rootDomainNamingContext attribute
for an Active Directory server.
For more information about the individual components of a LDAP URL please
see RFC4516.
- RTMP
- There's no official URL spec for RTMP so libcurl uses the URL syntax
supported by the underlying librtmp library. It has a syntax where it
wants a traditional URL, followed by a space and a series of
space-separated name=value pairs.
While space is not typically a "legal" letter, libcurl accepts
them. When a user wants to pass in a '#' (hash) character it will be
treated as a fragment and get cut off by libcurl if provided literally.
You will instead have to escape it by providing it as backslash and its
ASCII value in hexadecimal: "\23".
DEFAULT¶
There is no default URL. If this option isn't set, no transfer can be performed.
PROTOCOLS¶
All
EXAMPLE¶
curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
AVAILABILITY¶
POP3 and SMTP added in 7.31.0
RETURN VALUE¶
Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient
heap space.
SEE ALSO¶
CURLOPT_VERBOSE(3),
CURLOPT_PROTOCOLS(3),
curl_easy_perform(3)