Provided by: libcurl4-doc_7.81.0-1ubuntu1.20_all bug

NAME

       CURLOPT_URL - URL for this transfer

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 null-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 does not 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 is missing a scheme name (such as "http://" or "ftp://" etc) then libcurl will make a
       guess based on the host. If the outermost sub-domain name matches DICT, FTP, IMAP,  LDAP,  POP3  or  SMTP
       then  that  protocol  will be used, otherwise HTTP will be used. Since 7.45.0 guessing can be disabled by
       setting a default protocol, see CURLOPT_DEFAULT_PROTOCOL(3) for details.

       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.

       The CURLOPT_URL(3) string will be ignored if CURLOPT_CURLU(3) is set.

       CURLOPT_URL(3) or CURLOPT_CURLU(3) must be set before a transfer is started.

       The application does not have to keep the string around after setting this option.

ENCODING

       The string pointed to in the CURLOPT_URL(3) argument is generally expected to be a sequence of characters
       using an ASCII compatible encoding.

       If libcurl is built with IDN support, the server name part of the URL can use an "international name"  by
       using  the  current  encoding  (according  to locale) or UTF-8 (when winidn is used; or a Windows Unicode
       build using libidn2).

       If libcurl is built without IDN support, the server name is used exactly as specified when passed to  the
       name resolver functions.

DEFAULT

       There is no default URL. If this option is not set, no transfer can be performed.

SECURITY CONCERNS

       Applications may at times find it convenient to allow users to specify URLs for various purposes and that
       string would then end up fed to this option.

       Getting a URL from an external untrusted party will bring reasons for several security concerns:

       If you have an application that runs as or in a server application, getting an unfiltered URL can  easily
       trick  your  application  to  access  a  local  resource instead of a remote. Protecting yourself against
       localhost accesses is hard when accepting user provided URLs.

       Such custom URLs can also access other ports than you planned as port numbers are part of the regular URL
       format.  The combination of a local host and a custom port number can allow external users to play tricks
       with your local services.

       Accepting external URLs may also use other protocols than http:// or other  common  ones.  Restrict  what
       accept with CURLOPT_PROTOCOLS(3).

       User  provided  URLs  can  also  be  made  to  point to sites that redirect further on (possibly to other
       protocols too). Consider your CURLOPT_FOLLOWLOCATION(3) and CURLOPT_REDIR_PROTOCOLS(3) settings.

PROTOCOLS

       All

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

         curl_easy_perform(curl);
       }

AVAILABILITY

       POP3 and SMTP were added in 7.31.0

RETURN VALUE

       Returns CURLE_OK on success or CURLE_OUT_OF_MEMORY if there was insufficient heap space.

       Note that curl_easy_setopt(3) will not actually parse the given string so given a bad URL, it will not be
       detected until curl_easy_perform(3) or similar is called.

SEE ALSO

       CURLOPT_VERBOSE(3),      CURLOPT_PROTOCOLS(3),     CURLOPT_FORBID_REUSE(3),     CURLOPT_FRESH_CONNECT(3),
       curl_easy_perform(3), CURLINFO_REDIRECT_URL(3), CURLOPT_PATH_AS_IS(3), CURLOPT_CURLU(3),