DOKK / manpages / debian 12 / libcurl4-doc / curl_url_get.3.en
curl_url_get(3) libcurl Manual curl_url_get(3)

curl_url_get - extract a part from a URL

#include <curl/curl.h>
CURLUcode curl_url_get(CURLU *url,

CURLUPart what,
char **part,
unsigned int flags)

Given the url handle of an already parsed URL, this function lets the user extract individual pieces from it.

The what argument should be the particular part to extract (see list below) and part 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 part pointer must be freed with curl_free(3) after use.

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

If the handle has no port stored, this option will make curl_url_get(3) return the default port for the used scheme.
If the handle has no scheme stored, this option will make curl_url_get(3) return the default scheme instead of error.
Instructs curl_url_get(3) to not return a port number if it matches the default port for the scheme.
Asks curl_url_get(3) to URL decode the contents before returning it. It will not attempt to decode the scheme, the port number or the full URL.

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

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

If there's any byte values lower than 32 in the decoded string, the get operation will return an error instead.

If set, will make curl_url_get(3) URL encode the host name part when a full URL is retrieved. If not set (default), libcurl returns the URL with the host name "raw" to support IDN names to appear as-is. IDN host names are typically using non-ASCII bytes that otherwise will be percent-encoded.

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

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 will make curl_url_get(3) return CURLUE_LACKS_IDN if the host name contains anything outside the ASCII range.

(Added in curl 7.88.0)

When asked to return the full URL, curl_url_get(3) will return a normalized and possibly cleaned up version of what was previously parsed.
Scheme cannot be URL decoded on get.
The host name. If it is an IPv6 numeric address, the zone id will not be part of it but is provided separately in CURLUPART_ZONEID. IPv6 numerical addresses are returned within brackets ([]).
If the host name is a numeric IPv6 address, this field might also be set.
Port cannot be URL decoded on get.
part will be '/' even if no path is supplied in the URL.
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 will lead part to be set to NULL. A zero-length query will lead part to be set to a zero-length string.

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


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);
}

Added in 7.62.0. CURLUPART_ZONEID was added in 7.65.0.

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.

curl_url_cleanup(3), curl_url(3), curl_url_set(3), curl_url_dup(3), curl_url_strerror(3), CURLOPT_CURLU(3)

January 2, 2023 libcurl 7.88.1