Ubuntu Manpage: curl_url_set

Provided by: libcurl4-doc_8.12.1-3ubuntu1_all

NAME

       curl_url_set - set a URL part

SYNOPSIS

       #include <curl/curl.h>

       CURLUcode curl_url_set(CURLU *url,
                              CURLUPart part,
                              const char *content,
                              unsigned int flags);

DESCRIPTION

       The  url  handle  to  work  on,  passed  in as the first argument, must be a handle previously created by
       curl_url(3) or curl_url_dup(3).

       This function sets or updates individual URL components, or parts, held by  the  URL  object  the  handle
       identifies.

       The part argument should identify the particular URL part (see list below) to set or change, with content
       pointing  to  a null-terminated string with the new contents for that URL part. The contents should be in
       the form and encoding they would use in a URL: URL encoded.

       When setting a part in the URL object that was previously already set, it  replaces  the  data  that  was
       previously stored for that part with the new content.

       The  caller  does  not  have  to  keep content around after a successful call as this function copies the
       content.

       Setting a part to a NULL pointer removes that part's contents from the CURLU handle.

       This function has an 8 MB maximum length limit for all  provided  input  strings.   In  the  real  world,
       excessively long fields in URLs cause problems even if this function accepts them.

       When  setting  or updating contents of individual URL parts, curl_url_set(3) might accept data that would
       not be otherwise possible to set in the string when it gets populated as a result of a  full  URL  parse.
       Beware. If done so, extracting a full URL later on from such components might render an invalid URL.

       The flags argument is a bitmask with independent features.

PARTS

CURLUPART_URL
Allows the full URL of the handle to be replaced. If the handle already is populated with a URL,
the new URL can be relative to the previous.

When successfully setting a new URL, relative or absolute, the handle contents is replaced with
the components of the newly set URL.

Pass a pointer to a null-terminated string to the url parameter. The string must point to a
correctly formatted "RFC 3986+" URL or be a NULL pointer. The URL parser only understands and
parses the subset of URLS that are "hierarchical" and therefore contain a :// separator - not the
ones that are normally specified with only a colon separator.

By default this API only parses URLs using schemes for protocols that are supported built-in. To
make libcurl parse URLs generically even for schemes it does not know about, the
CURLU_NON_SUPPORT_SCHEME flags bit must be set. Otherwise, this function returns
CURLUE_UNSUPPORTED_SCHEME for URL schemes it does not recognize.

Unless CURLU_NO_AUTHORITY is set, a blank hostname is not allowed in the URL.

When a full URL is set (parsed), the hostname component is stored URL decoded.

CURLUPART_SCHEME
Scheme cannot be URL decoded on set. libcurl only accepts setting schemes up to 40 bytes long.

CURLUPART_USER
If only the user part is set and not the password, the URL is represented with a blank password.

CURLUPART_PASSWORD
If only the password part is set and not the user, the URL is represented with a blank user.

CURLUPART_OPTIONS
The options field is an optional field that might follow the password in the userinfo part. It is
only recognized/used when parsing URLs for the following schemes: pop3, smtp and imap. This
function however allows users to independently set this field.

CURLUPART_HOST
The hostname. If it is International Domain Name (IDN) the string must then be encoded as your
locale says or UTF-8 (when WinIDN is used). If it is a bracketed IPv6 numeric address it may
contain a zone id (or you can use CURLUPART_ZONEID).

Note that if you set an IPv6 address, it gets ruined and causes an error if you also set the
CURLU_URLENCODE flag.

Unless CURLU_NO_AUTHORITY is set, a blank hostname is not allowed to set.

CURLUPART_ZONEID
If the hostname is a numeric IPv6 address, this field can also be set.

CURLUPART_PORT
The port number cannot be URL encoded on set. The given port number is provided as a string and
the decimal number in it must be between 0 and 65535. Anything else returns an error.

CURLUPART_PATH
If a path is set in the URL without a leading slash, a slash is prepended automatically.

CURLUPART_QUERY
The query part gets spaces converted to pluses when asked to URL encode on set with the
CURLU_URLENCODE bit.

If used together with the CURLU_APPENDQUERY bit, the provided part is appended on the end of the
existing query.

The question mark in the URL is not part of the actual query contents.

CURLUPART_FRAGMENT
The hash sign in the URL is not part of the actual fragment contents.

FLAGS

The flags argument is zero, one or more bits set in a bitmask.

CURLU_APPENDQUERY
Can be used when setting the CURLUPART_QUERY component. The provided new part is then appended at
the end of the existing query - and if the previous part did not end with an ampersand (&), an
ampersand gets inserted before the new appended part.

When CURLU_APPENDQUERY is used together with CURLU_URLENCODE, the first '=' symbol is not URL
encoded.

CURLU_NON_SUPPORT_SCHEME
If set, allows curl_url_set(3) to set a non-supported scheme. It then of course cannot know if the
provided scheme is a valid one or not.

CURLU_URLENCODE
When set, curl_url_set(3) URL encodes the part on entry, except for scheme, port and URL.

When setting the path component with URL encoding enabled, the slash character is skipped.

The query part gets space-to-plus converted before the URL conversion is applied.

This URL encoding is charset unaware and converts the input in a byte-by-byte manner.

CURLU_DEFAULT_SCHEME
If set, allows the URL to be set without a scheme and then sets that to the default scheme: HTTPS.
Overrides the CURLU_GUESS_SCHEME option if both are set.

CURLU_GUESS_SCHEME
If set, allows the URL to be set without a scheme and it instead "guesses" which scheme that was
intended based on the hostname. If the outermost subdomain name matches DICT, FTP, IMAP, LDAP,
POP3 or SMTP then that scheme is used, otherwise it picks HTTP. Conflicts with the
CURLU_DEFAULT_SCHEME option which takes precedence if both are set.

If guessing is not allowed and there is no default scheme set, trying to parse a URL without a
scheme returns error.

If the scheme ends up set as a result of guessing, i.e. it is not actually present in the parsed
URL, it can later be figured out by using the CURLU_NO_GUESS_SCHEME flag when subsequently getting
the URL or the scheme with curl_url_get(3).

CURLU_NO_AUTHORITY
If set, skips authority checks. The RFC allows individual schemes to omit the host part (normally
the only mandatory part of the authority), but libcurl cannot know whether this is permitted for
custom schemes. Specifying the flag permits empty authority sections, similar to how file scheme
is handled.

CURLU_PATH_AS_IS
When set for CURLUPART_URL, this skips the normalization of the path. That is the procedure where
libcurl otherwise removes sequences of dot-slash and dot-dot etc. The same option used for
transfers is called CURLOPT_PATH_AS_IS(3).

CURLU_ALLOW_SPACE
If set, the URL parser allows space (ASCII 32) where possible. The URL syntax does normally not
allow spaces anywhere, but they should be encoded as %20 or '+'. When spaces are allowed, they are
still not allowed in the scheme. When space is used and allowed in a URL, it is stored as-is
unless CURLU_URLENCODE is also set, which then makes libcurl URL encode the space before stored.
This affects how the URL is constructed when curl_url_get(3) is subsequently used to extract the
full URL or individual parts. (Added in 7.78.0)

CURLU_DISALLOW_USER
If set, the URL parser does not accept embedded credentials for the CURLUPART_URL, and instead
returns CURLUE_USER_NOT_ALLOWED for such URLs.

PROTOCOLS

       This functionality affects all supported protocols

EXAMPLE

       int main(void)
       {
         CURLUcode rc;
         CURLU *url = curl_url();
         rc = curl_url_set(url, CURLUPART_URL, "https://example.com", 0);
         if(!rc) {
           /* change it to an FTP URL */
           rc = curl_url_set(url, CURLUPART_SCHEME, "ftp", 0);
         }
         curl_url_cleanup(url);
       }

AVAILABILITY

       Added in curl 7.62.0

RETURN VALUE

       Returns   a   CURLUcode   error  value,  which  is  CURLUE_OK  (0)  if  everything  went  fine.  See  the
       libcurl-errors(3) man page for the full list with descriptions.

       The input string passed to curl_url_set(3) must be shorter  than  eight  million  bytes.  Otherwise  this
       function returns CURLUE_MALFORMED_INPUT.

       If this function returns an error, no URL part is set.