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= nng_url_parse(3)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This document is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt). A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//
== NAME
nng_url_parse - create URL structure from a string
== SYNOPSIS
[source, c]
----
#include <nng/nng.h>
int nng_url_parse(nng_url **urlp, const char *str);
----
== DESCRIPTION
The `nng_url_parse()` function parses the string _str_ containing an
https://tools.ietf.org/html/rfc3986[RFC 3986] compliant URL, and creates
a structure containing the results. A pointer to the resulting structure
is stored in _urlp_.
The `nng_url` structure has at least the following members:
[source, c]
----
struct nng_url {
char *u_rawurl; // Unparsed URL, with minimal canonicalization.
char *u_scheme; // Scheme, such as "http"; always lower case.
char *u_userinfo; // Userinfo component, or NULL.
char *u_host; // Full host, including port if present.
char *u_hostname; // Hostname only (or address), or empty string.
char *u_port; // Port number, may be default or empty string.
char *u_path; // Path if present, empty string otherwise.
char *u_query; // Query info if present, NULL otherwise.
char *u_fragment; // Fragment if present, NULL otherwise.
char *u_requri; // Request-URI (path[?query][#fragment])
};
----
=== URL Canonicalization
The `nng_url_parse()` function also canonicalizes the results, as
follows:
1. The URL is parsed into the various components.
2. The `u_scheme`, `u_hostname`, `u_host`, and `u_port` members are
converted to lower case.
3. Percent-encoded values for
https://tools.ietf.org/html/rfc3986#section-2.3[unreserved characters]
converted to their unencoded forms.
4. Additionally URL percent-encoded values for characters in the path
and with numeric values larger than 127 (i.e. not ASCII) are decoded.
5. The resulting `u_path` is checked for invalid UTF-8 sequences, consisting
of surrogate pairs, illegal byte sequences, or overlong encodings.
If this check fails, then the entire URL is considered invalid, and
the function returns `NNG_EINVAL`.
6. Path segments consisting of `.` and `..` are resolved as per
https://tools.ietf.org/html/rfc3986#section-6.2.2.3[RFC 3986 6.2.2.3].
7. Further, empty path segments are removed, meaning that duplicate
slash (`/`) separators are removed from the path.
8. If a port was not specified, but the scheme defines a default
port, then `u_port` will be filled in with the value of the default port.
TIP: Only the `u_userinfo`, `u_query`, and `u_fragment` members will ever be
`NULL`. The other members will be filled in with either default values
or the empty string if they cannot be determined from _str_.
== RETURN VALUES
This function returns 0 on success, and non-zero otherwise.
== ERRORS
[horizontal]
`NNG_ENOMEM`:: Insufficient free memory exists to allocate a message.
`NNG_EINVAL`:: An invalid URL was supplied.
== SEE ALSO
[.text-left]
xref:nng_url_clone.3.adoc[nng_url_clone(3)],
xref:nng_url_free.3.adoc[nng_url_free(3)],
xref:nng_strerror.3.adoc[nng_strerror(3)],
xref:nng.7.adoc[nng(7)]
|
