curl/docs/libcurl/curl_url_get.3

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.TH curl_url_get 3 "6 Aug 2018" "libcurl" "libcurl"
.SH NAME
curl_url_get - extract a part from a URL
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLUcode curl_url_get(CURLU *url,
                       CURLUPart what,
                       char **part,
                       unsigned int flags)
.fi
.SH DESCRIPTION
Given the \fIurl\fP handle of an already parsed URL, this function lets the
user extract individual pieces from it.

The \fIwhat\fP argument should be the particular part to extract (see list
below) and \fIpart\fP points to a 'char *' to get updated to point to a newly
allocated string with the contents.

The URL API has no particular maximum length for URL fiends. In the real
world, excessively long field in URLs will cause problems even if this API
accepts them. This function can return very large ones.

The \fIflags\fP argument is a bitmask with individual features.

The returned part pointer must be freed with \fIcurl_free(3)\fP after use.
.SH FLAGS
The flags argument is zero, one or more bits set in a bitmask.
.IP CURLU_DEFAULT_PORT
If the handle has no port stored, this option will make \fIcurl_url_get(3)\fP
return the default port for the used scheme.
.IP CURLU_DEFAULT_SCHEME
If the handle has no scheme stored, this option will make
\fIcurl_url_get(3)\fP return the default scheme instead of error.
.IP CURLU_NO_DEFAULT_PORT
Instructs \fIcurl_url_get(3)\fP to not return a port number if it matches the
default port for the scheme.
.IP CURLU_URLDECODE
Asks \fIcurl_url_get(3)\fP 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.
.IP CURLU_URLENCODE
If set, will make \fIcurl_url_get(3)\fP 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.
.IP CURLU_PUNYCODE
If set and \fICURLU_URLENCODE\fP is not set, and asked to retrieve the
\fBCURLUPART_HOST\fP or \fBCURLUPART_URL\fP 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
\fIcurl_url_get(3)\fP return \fICURLUE_LACKS_IDN\fP if the host name contains
anything outside the ASCII range.

(Added in curl 7.88.0)
.IP CURLU_PUNY2IDN
If set and asked to retrieve the \fBCURLUPART_HOST\fP or \fBCURLUPART_URL\fP
parts, libcurl returns the host name in its IDN (International Domain Name)
UTF-8 version if it otherwise is a punycode version. If the punycode cannot be
converted to IDN correct, libcurl returns \fICURLUE_BAD_HOSTNAME\fP.

If libcurl is built without IDN capabilities, using this bit will make
\fIcurl_url_get(3)\fP return \fICURLUE_LACKS_IDN\fP if the host name is using
punycode.

(Added in curl 8.3.0)
.SH PARTS
.IP CURLUPART_URL
When asked to return the full URL, \fIcurl_url_get(3)\fP will return a
normalized and possibly cleaned up version of what was previously parsed.

We advise using the \fICURLU_PUNYCODE\fP option to get the URL as "normalized"
as possible since IDN allows host names to be written in many different ways
that still end up the same punycode version.
.IP CURLUPART_SCHEME
Scheme cannot be URL decoded on get.
.IP CURLUPART_USER
.IP CURLUPART_PASSWORD
.IP 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.
.IP CURLUPART_HOST
The host name. If it is an IPv6 numeric address, the zone id will not be part
of it but is provided separately in \fICURLUPART_ZONEID\fP. 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.
.IP CURLUPART_ZONEID
If the host name is a numeric IPv6 address, this field might also be set.
.IP 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.
.IP CURLUPART_PATH
The \fIpart\fP will be '/' even if no path is supplied in the URL. A URL path
always starts with a slash.
.IP 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 will lead \fIpart\fP to be set to NULL.
A zero-length query will lead \fIpart\fP 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.
.IP 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.
.SH EXAMPLE
.nf
  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);
  }
.fi
.SH AVAILABILITY
Added in 7.62.0. CURLUPART_ZONEID was added in 7.65.0.
.SH RETURN VALUE
Returns a CURLUcode error value, which is CURLUE_OK (0) if everything went
fine. See the \fIlibcurl-errors(3)\fP man page for the full list with
descriptions.

If this function returns an error, no URL part is returned.
.SH "SEE ALSO"
.BR curl_url_cleanup "(3), " curl_url "(3), " curl_url_set "(3), "
.BR curl_url_dup "(3), " curl_url_strerror "(3), " CURLOPT_CURLU "(3)"