1= nng_url_parse(3)
2//
3// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
4// Copyright 2018 Capitar IT Group BV <info@capitar.com>
5//
6// This document is supplied under the terms of the MIT License, a
7// copy of which should be located in the distribution where this
8// file was obtained (LICENSE.txt).  A copy of the license may also be
9// found online at https://opensource.org/licenses/MIT.
10//
11
12== NAME
13
14nng_url_parse - create URL structure from a string
15
16== SYNOPSIS
17
18[source, c]
19----
20#include <nng/nng.h>
21
22int nng_url_parse(nng_url **urlp, const char *str);
23----
24
25== DESCRIPTION
26
27The `nng_url_parse()` function parses the string _str_ containing an
28https://tools.ietf.org/html/rfc3986[RFC 3986] compliant URL, and creates
29an
30xref:nng_url.5.adoc[`nng_url`] structure containing the results.
31A pointer to the resulting structure is stored in _urlp_.
32
33The structure may disposed of when no longer needed by calling
34xref:nng_url_free.3.adoc[`nng_url_free()`].
35
36=== URL Canonicalization
37
38The `nng_url_parse()` function also canonicalizes the results, as
39follows:
40
41  1. The URL is parsed into the various components.
42  2. The `u_scheme`, `u_hostname`, `u_host`, and `u_port` members are
43     converted to lower case.
44  3. Percent-encoded values for
45     https://tools.ietf.org/html/rfc3986#section-2.3[unreserved characters]
46     converted to their unencoded forms.
47  4. Additionally URL percent-encoded values for characters in the path
48     and with numeric values larger than 127 (i.e. not ASCII) are decoded.
49  5. The resulting `u_path` is checked for invalid UTF-8 sequences, consisting
50     of surrogate pairs, illegal byte sequences, or overlong encodings.
51     If this check fails, then the entire URL is considered invalid, and
52     the function returns `NNG_EINVAL`.
53  6. Path segments consisting of `.` and `..` are resolved as per
54     https://tools.ietf.org/html/rfc3986#section-6.2.2.3[RFC 3986 6.2.2.3].
55  7. Further, empty path segments are removed, meaning that duplicate
56     slash (`/`) separators are removed from the path.
57  8. If a port was not specified, but the scheme defines a default
58     port, then `u_port` will be filled in with the value of the default port.
59
60TIP: Only the `u_userinfo`, `u_query`, and `u_fragment` members will ever be
61     `NULL`.  The other members will be filled in with either default values
62     or the empty string if they cannot be determined from _str_.
63
64== RETURN VALUES
65
66This function returns 0 on success, and non-zero otherwise.
67
68
69== ERRORS
70
71[horizontal]
72`NNG_ENOMEM`:: Insufficient free memory exists to allocate a message.
73`NNG_EINVAL`:: An invalid URL was supplied.
74
75
76== SEE ALSO
77
78[.text-left]
79xref:nng_url_clone.3.adoc[nng_url_clone(3)],
80xref:nng_url_free.3.adoc[nng_url_free(3)],
81xref:nng_strerror.3.adoc[nng_strerror(3)],
82xref:nng_url.5.adoc[nng_url(5)],
83xref:nng.7.adoc[nng(7)]
84