docs/libcurl/libcurl-url.3

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.TH libcurl 3 "10 Sep 2018" "libcurl" "libcurl url interface"
.SH NAME
libcurl-url \- URL interface overview
.SH DESCRIPTION
The URL interface provides a set of functions for parsing and generating URLs.
.SH INCLUDE
You still only include <curl/curl.h> in your code. Note that the URL API was
introduced in 7.62.0.
.SH CREATE
Create a handle that holds URL info and resources with \fIcurl_url(3)\fP:

  CURLU *h = curl_url();
.SH CLEANUP
When done with it, clean it up with \fIcurl_url_cleanup(3)\fP:

  curl_url_cleanup(h);
.SH DUPLICATE
When you need a copy of a handle, just duplicate it with \fIcurl_url_dup(3)\fP:

  CURLU *nh = curl_url_dup(h);
.SH PARSING
By "setting" a URL to the handle with \fIcurl_url_set(3)\fP, the URL is parsed
and stored in the handle. If the URL is not syntactically correct it will
return an error instead.

.nf
  rc = curl_url_set(h, CURLUPART_URL,
                    "https://example.com:449/foo/bar?name=moo", 0);
.fi

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.
.SH REDIRECT
When a handle already contains info about a URL, setting a relative URL will
make it "redirect" to adapt to it.

  rc = curl_url_set(h, CURLUPART_URL, "../test?another", 0);
.SH "GET URL"
The `CURLU` handle represents a URL and you can easily extract that with
\fIcurl_url_get(3)\fP:

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

.nf
  rc = curl_url_get(h, CURLUPART_HOST, &host, 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_PASSWORD, &password, 0);
  rc = curl_url_get(h, CURLUPART_PORT, &port, 0);
  rc = curl_url_get(h, CURLUPART_PATH, &path, 0);
  rc = curl_url_get(h, CURLUPART_QUERY, &query, 0);
  rc = curl_url_get(h, CURLUPART_FRAGMENT, &fragment, 0);
.fi

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 \fIcurl_free(3)\fP when you're done
with it!
.SH "SET PARTS"
A user set individual URL parts, either after having parsed a full URL or
instead of parsing such.

.nf
  rc = curl_url_set(urlp, CURLUPART_HOST, "www.example.com", 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_PASSWORD, "doe", 0);
  rc = curl_url_set(urlp, CURLUPART_PORT, "443", 0);
  rc = curl_url_set(urlp, CURLUPART_PATH, "/index.html", 0);
  rc = curl_url_set(urlp, CURLUPART_QUERY, "name=john", 0);
  rc = curl_url_set(urlp, CURLUPART_FRAGMENT, "anchor", 0);
.fi

Set parts are not URL encoded unless the user asks for it with the
`CURLU_URLENCODE` flag.
.SH "APPENDQUERY"
An application can append a string to the right end of the query part with the
`CURLU_APPENDQUERY` flag to \fIcurl_url_set(3)\fP.

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:

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

It will even notice the lack of an ampersand (`&`) separator so it will inject
one too, and the handle's full URL will then equal
`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 will skip 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:

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

Now the URL looks like
.nf
  https://example.com/?shoes=2&hat=1&candy=N%26N`
.fi
.SH "SEE ALSO"
.BR curl_url "(3), " curl_url_cleanup "(3), " curl_url_get "(3), "
.BR curl_url_dup "(3), " curl_url_set "(3), " CURLOPT_URL "(3), "