163 lines
4.3 KiB
Markdown
163 lines
4.3 KiB
Markdown
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---
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c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
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SPDX-License-Identifier: curl
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Title: libcurl
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Section: 3
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Source: libcurl
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See-also:
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- CURLOPT_URL (3)
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- curl_url (3)
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- curl_url_cleanup (3)
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- curl_url_dup (3)
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- curl_url_get (3)
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- curl_url_set (3)
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- curl_url_strerror (3)
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---
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# NAME
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libcurl-url - URL interface overview
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# DESCRIPTION
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The URL interface provides functions for parsing and generating URLs.
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# INCLUDE
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You still only include \<curl/curl.h\> in your code.
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# CREATE
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Create a handle that holds URL info and resources with curl_url(3):
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~~~c
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CURLU *h = curl_url();
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~~~
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# CLEANUP
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When done with it, clean it up with curl_url_cleanup(3)
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~~~c
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curl_url_cleanup(h);
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~~~
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# DUPLICATE
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When you need a copy of a handle, just duplicate it with curl_url_dup(3):
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~~~c
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CURLU *nh = curl_url_dup(h);
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~~~
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# PARSING
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By setting a URL to the handle with curl_url_set(3), the URL is parsed
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and stored in the handle. If the URL is not syntactically correct it returns
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an error instead.
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~~~c
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rc = curl_url_set(h, CURLUPART_URL,
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"https://example.com:449/foo/bar?name=moo", 0);
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~~~
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The zero in the fourth argument is a bitmask for changing specific features.
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If successful, this stores the URL in its individual parts within the handle.
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# REDIRECT
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When a handle already contains info about a URL, setting a relative URL makes
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it "redirect" to that.
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~~~c
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rc = curl_url_set(h, CURLUPART_URL, "../test?another", 0);
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~~~
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# GET URL
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The **CURLU** handle represents a URL and you can easily extract that with
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curl_url_get(3):
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~~~c
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char *url;
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rc = curl_url_get(h, CURLUPART_URL, &url, 0);
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curl_free(url);
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~~~
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The zero in the fourth argument is a bitmask for changing specific features.
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# GET PARTS
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When a URL has been parsed or parts have been set, you can extract those
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pieces from the handle at any time.
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~~~c
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rc = curl_url_get(h, CURLUPART_FRAGMENT, &fragment, 0);
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rc = curl_url_get(h, CURLUPART_HOST, &host, 0);
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rc = curl_url_get(h, CURLUPART_PASSWORD, &password, 0);
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rc = curl_url_get(h, CURLUPART_PATH, &path, 0);
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rc = curl_url_get(h, CURLUPART_PORT, &port, 0);
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rc = curl_url_get(h, CURLUPART_QUERY, &query, 0);
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rc = curl_url_get(h, CURLUPART_SCHEME, &scheme, 0);
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rc = curl_url_get(h, CURLUPART_USER, &user, 0);
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rc = curl_url_get(h, CURLUPART_ZONEID, &zoneid, 0);
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~~~
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Extracted parts are not URL decoded unless the user also asks for it with the
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*CURLU_URLDECODE* flag set in the fourth bitmask argument.
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Remember to free the returned string with curl_free(3) when you are done
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with it!
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# SET PARTS
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A user set individual URL parts, either after having parsed a full URL or
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instead of parsing such.
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~~~c
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rc = curl_url_set(urlp, CURLUPART_FRAGMENT, "anchor", 0);
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rc = curl_url_set(urlp, CURLUPART_HOST, "www.example.com", 0);
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rc = curl_url_set(urlp, CURLUPART_PASSWORD, "doe", 0);
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rc = curl_url_set(urlp, CURLUPART_PATH, "/index.html", 0);
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rc = curl_url_set(urlp, CURLUPART_PORT, "443", 0);
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rc = curl_url_set(urlp, CURLUPART_QUERY, "name=john", 0);
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rc = curl_url_set(urlp, CURLUPART_SCHEME, "https", 0);
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rc = curl_url_set(urlp, CURLUPART_USER, "john", 0);
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rc = curl_url_set(urlp, CURLUPART_ZONEID, "eth0", 0);
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~~~
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Set parts are not URL encoded unless the user asks for it with the
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*CURLU_URLENCODE* flag.
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# CURLU_APPENDQUERY
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An application can append a string to the right end of the query part with the
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*CURLU_APPENDQUERY* flag to curl_url_set(3).
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Imagine a handle that holds the URL "https://example.com/?shoes=2". An
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application can then add the string "hat=1" to the query part like this:
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~~~c
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rc = curl_url_set(urlp, CURLUPART_QUERY, "hat=1", CURLU_APPENDQUERY);
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~~~
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It notices the lack of an ampersand (&) separator and injects one, and the
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handle's full URL then equals "https://example.com/?shoes=2&hat=1".
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The appended string can of course also get URL encoded on add, and if asked to
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URL encode, the encoding process skips the '=' character. For example, append
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"candy=N&N" to what we already have, and URL encode it to deal with the
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ampersand in the data:
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~~~c
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rc = curl_url_set(urlp, CURLUPART_QUERY, "candy=N&N",
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CURLU_APPENDQUERY | CURLU_URLENCODE);
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~~~
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Now the URL looks like
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~~~c
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https://example.com/?shoes=2&hat=1&candy=N%26N
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~~~
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# AVAILABILITY
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The URL API was introduced in libcurl 7.62.0.
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A URL with a literal IPv6 address can be parsed even when IPv6 support is not
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enabled.
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