Tribblix: manual page: curl_url

curl_url_get(3) Introduction to Library Functions curl_url_get(3)

NAME

curl_url_get - extract a part from a URL

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

Given a url handle of a URL object, this function extracts an
individual piece or the full URL from it.

The part argument specifies which part to extract (see list below)
and content points to a 'char *' to get updated to point to a newly
allocated string with the contents.

The flags argument is a bitmask with individual features.

The returned content pointer must be freed with curl_free(3) after
use.

FLAGS

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

CURLU_DEFAULT_PORT
If the handle has no port stored, this option makes
curl_url_get(3) return the default port for the used scheme.

CURLU_DEFAULT_SCHEME
If the handle has no scheme stored, this option makes
curl_url_get(3) return the default scheme instead of error.

CURLU_NO_DEFAULT_PORT
Instructs curl_url_get(3) to not return a port number if it
matches the default port for the scheme.

CURLU_URLDECODE
Asks curl_url_get(3) to URL decode the contents before
returning it. It does not decode the scheme, the port number
or the full URL.

The query component also gets plus-to-space conversion as a
bonus when this bit is set.

Note that this URL decoding is charset unaware and you get a
zero terminated string back with data that could be intended
for a particular encoding.

If there are byte values lower than 32 in the decoded string,
the get operation returns an error instead.

CURLU_URLENCODE
If set, curl_url_get(3) URL encodes the hostname part when a
full URL is retrieved. If not set (default), libcurl returns
the URL with the hostname raw to support IDN names to appear
as-is. IDN hostnames are typically using non-ASCII bytes that
otherwise gets percent-encoded.

Note that even when not asking for URL encoding, the '%' (byte
37) is URL encoded to make sure the hostname remains valid.

CURLU_PUNYCODE
If set and CURLU_URLENCODE is not set, and asked to retrieve
the CURLUPART_HOST or CURLUPART_URL parts, libcurl returns the
host name in its punycode version if it contains any non-ASCII
octets (and is an IDN name).

If libcurl is built without IDN capabilities, using this bit
makes curl_url_get(3) return CURLUE_LACKS_IDN if the hostname
contains anything outside the ASCII range.

(Added in curl 7.88.0)

CURLU_PUNY2IDN
If set and asked to retrieve the CURLUPART_HOST or
CURLUPART_URL parts, libcurl returns the hostname in its IDN
(International Domain Name) UTF-8 version if it otherwise is a
punycode version. If the punycode name cannot be converted to
IDN correctly, libcurl returns CURLUE_BAD_HOSTNAME.

If libcurl is built without IDN capabilities, using this bit
makes curl_url_get(3) return CURLUE_LACKS_IDN if the hostname
is using punycode.

(Added in curl 8.3.0)

CURLU_GET_EMPTY
When this flag is used in curl_url_get(), it makes the
function return empty query and fragments parts or when used
in the full URL. By default, libcurl otherwise considers empty
parts non-existing.

An empty query part is one where this is nothing following the
question mark (before the possible fragment). An empty
fragments part is one where there is nothing following the
hash sign.

(Added in curl 8.8.0)

CURLU_NO_GUESS_SCHEME
When this flag is used in curl_url_get(), it treats the scheme
as non-existing if it was set as a result of a previous guess;
when CURLU_GUESS_SCHEME was used parsing a URL.

Using this flag when getting CURLUPART_SCHEME if the scheme
was set as the result of a guess makes curl_url_get() return
CURLUE_NO_SCHEME.

Using this flag when getting CURLUPART_URL if the scheme was
set as the result of a guess makes curl_url_get() return the
full URL without the scheme component. Such a URL can then
only be parsed with curl_url_set() if CURLU_GUESS_SCHEME is
used.

(Added in curl 8.9.0)

PARTS

CURLUPART_URL
When asked to return the full URL, curl_url_get(3) returns a
normalized and possibly cleaned up version using all available
URL parts.

We advise using the CURLU_PUNYCODE option to get the URL as
"normalized" as possible since IDN allows hostnames to be
written in many different ways that still end up the same
punycode version.

Zero-length queries and fragments are excluded from the URL
unless CURLU_GET_EMPTY is set.

CURLUPART_SCHEME
Scheme cannot be URL decoded on get.

CURLUPART_USER

CURLUPART_PASSWORD

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.
The URL API still allows users to set and get this field
independently of scheme when not parsing full URLs.

CURLUPART_HOST
The hostname. If it is an IPv6 numeric address, the zone id is
not part of it but is provided separately in CURLUPART_ZONEID.
IPv6 numerical addresses are returned within brackets ([]).

IPv6 names are normalized when set, which should make them as
short as possible while maintaining correct syntax.

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

CURLUPART_PORT
A port cannot be URL decoded on get. This number is returned
in a string just like all other parts. That string is
guaranteed to hold a valid port number in ASCII using base 10.

CURLUPART_PATH
The part is always at least a slash ('/') even if no path was
supplied in the URL. A URL path always starts with a slash.

CURLUPART_QUERY
The initial question mark that denotes the beginning of the
query part is a delimiter only. It is not part of the query
contents.

A not-present query returns part set to NULL.

A zero-length query returns part as NULL unless
CURLU_GET_EMPTY is set.

The query part gets pluses converted to space when asked to
URL decode on get with the CURLU_URLDECODE bit.

CURLUPART_FRAGMENT
The initial hash sign that denotes the beginning of the
fragment is a delimiter only. It is not part of the fragment
contents.

A not-present fragment returns part set to NULL.

A zero-length fragment returns part as NULL unless
CURLU_GET_EMPTY is set.

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) {
char *scheme;
rc = curl_url_get(url, CURLUPART_SCHEME, &scheme, 0);
if(!rc) {
printf("the scheme is %s\n", scheme);
curl_free(scheme);
}
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.

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