Tribblix: manual page: libcurl-url.3

libcurl-url(3) Introduction to Library Functions libcurl-url(3)

NAME

libcurl-url - URL interface overview

DESCRIPTION

The URL interface provides functions for parsing and generating URLs.

INCLUDE

You still only include <curl/curl.h> in your code.

CREATE

Create a handle that holds URL info and resources with curl_url(3):
CURLU *h = curl_url();

CLEANUP

When done with it, clean it up with curl_url_cleanup(3)
curl_url_cleanup(h);

DUPLICATE

When you need a copy of a handle, just duplicate it with
curl_url_dup(3):
CURLU *nh = curl_url_dup(h);

PARSING

By setting a URL to the handle with curl_url_set(3), the URL is
parsed and stored in the handle. If the URL is not syntactically
correct it returns an error instead.
rc = curl_url_set(h, CURLUPART_URL,
"https://example.com:449/foo/bar?name=moo", 0);

The zero in the fourth argument is a bitmask for changing specific
features.

If successful, this stores the URL in its individual parts within the
handle.

REDIRECT

When a handle already contains info about a URL, setting a relative
URL makes it "redirect" to that.
rc = curl_url_set(h, CURLUPART_URL, "../test?another", 0);

GET URL

The CURLU handle represents a URL and you can easily extract that
with curl_url_get(3):
char *url;
rc = curl_url_get(h, CURLUPART_URL, &url, 0);
curl_free(url);
The zero in the fourth argument is a bitmask for changing specific
features.

GET PARTS

When a URL has been parsed or parts have been set, you can extract
those pieces from the handle at any time.

rc = curl_url_get(h, CURLUPART_FRAGMENT, &fragment, 0);
rc = curl_url_get(h, CURLUPART_HOST, &host, 0);
rc = curl_url_get(h, CURLUPART_PASSWORD, &password, 0);
rc = curl_url_get(h, CURLUPART_PATH, &path, 0);
rc = curl_url_get(h, CURLUPART_PORT, &port, 0);
rc = curl_url_get(h, CURLUPART_QUERY, &query, 0);
rc = curl_url_get(h, CURLUPART_SCHEME, &scheme, 0);
rc = curl_url_get(h, CURLUPART_USER, &user, 0);
rc = curl_url_get(h, CURLUPART_ZONEID, &zoneid, 0);

Extracted parts are not URL decoded unless the user also asks for it
with the CURLU_URLDECODE flag set in the fourth bitmask argument.

Remember to free the returned string with curl_free(3) when you are
done with it.

SET PARTS

A user set individual URL parts, either after having parsed a full
URL or instead of parsing such.

rc = curl_url_set(urlp, CURLUPART_FRAGMENT, "anchor", 0);
rc = curl_url_set(urlp, CURLUPART_HOST, "www.example.com", 0);
rc = curl_url_set(urlp, CURLUPART_PASSWORD, "doe", 0);
rc = curl_url_set(urlp, CURLUPART_PATH, "/index.html", 0);
rc = curl_url_set(urlp, CURLUPART_PORT, "443", 0);
rc = curl_url_set(urlp, CURLUPART_QUERY, "name=john", 0);
rc = curl_url_set(urlp, CURLUPART_SCHEME, "https", 0);
rc = curl_url_set(urlp, CURLUPART_USER, "john", 0);
rc = curl_url_set(urlp, CURLUPART_ZONEID, "eth0", 0);

Set parts are not URL encoded unless the user asks for it with the
CURLU_URLENCODE flag.

CURLU_APPENDQUERY
An application can append a string to the right end of the query part
with the CURLU_APPENDQUERY flag to curl_url_set(3).

Imagine a handle that holds the URL "https://example.com/?shoes=2".
An application can then add the string "hat=1" to the query part like
this:

rc = curl_url_set(urlp, CURLUPART_QUERY, "hat=1", CURLU_APPENDQUERY);

It notices the lack of an ampersand (&) separator and injects one,
and the handle's full URL then equals
"https://example.com/?shoes=2&hat=1".

The appended string can of course also get URL encoded on add, and if
asked to URL encode, the encoding process skips the '=' character.
For example, append "candy=N&N" to what we already have, and URL
encode it to deal with the ampersand in the data:

rc = curl_url_set(urlp, CURLUPART_QUERY, "candy=N&N",
CURLU_APPENDQUERY | CURLU_URLENCODE);

Now the URL looks like

https://example.com/?shoes=2&hat=1&candy=N%26N

NOTES

A URL with a literal IPv6 address can be parsed even when IPv6
support is not enabled.