uri_create_str.3.xml

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<refentry version="5.0" xml:id="uri_create_str-3" xmlns="http://docbook.org/ns" xml:lang="en">
  <info>
	<title>URI Functions</title>
	<productname>System Programmer's Manual</productname>
	<authorgroup>
	  <author>
		<personname>
		  <firstname>Mo</firstname>
		  <surname>McRoberts</surname>
		</personname>
	  </author>
	</authorgroup>
	<copyright>
	  <year>2012</year>
	  <holder>Mo McRoberts</holder>
	</copyright>
  </info>
  
  <refmeta>
	<refentrytitle>uri_create_str</refentrytitle>
	<manvolnum>3</manvolnum>
  </refmeta>
  
  <refnamediv>
	<refname>uri_create_str</refname>
	<refpurpose>parse a URI or IRI</refpurpose>
  </refnamediv>
  
  <refsect1>
	<title>Library</title>
	<para>URI parsing library (liburi, -luri)</para>
  </refsect1>

  <refsynopsisdiv>
	<funcsynopsis>
	  <funcsynopsisinfo>#include &lt;liburi.h&gt;</funcsynopsisinfo>
	  <funcprototype>
		<funcdef>URI *<function>uri_create_str</function></funcdef>
		<paramdef>const char *restrict <parameter>uristr</parameter></paramdef>
		<paramdef>const URI *restrict <parameter>base</parameter></paramdef>
	  </funcprototype>
	</funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
	<title>Description</title>
	<para>
	  The <function>uri_create_str</function> function parses a string in order
	  to produce a <type>URI</type> instance. If the URI to be parsed in
	  <parameter>uristr</parameter> is not absolute, and an absolute base URI
	  is supplied as <parameter>base</parameter>, the parsed URI will be
	  resolved relative to the base URI and the result will be an absolute
	  URI. If no base URI is supplied, the resulting URI instance may be
	  either absolute or relative, depending upon the contents of
	  <parameter>uristr</parameter>.
	</para>
	<para>
	  The resulting instance must be freed later using <citerefentry><refentrytitle><ulink url="uri_destroy.3.html">uri_destroy</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>.
	</para>
	<para>
	  URIs are normalised as they are parsed. Normalisation is performed
	  according to <ulink url="http://tools.ietf.org/html/rfc3986#section-6.2.2">section 6.2.2 of RFC3986</ulink>, and includes adjusting the case of any
	  scheme, hostname and percent-encoded characters so as to be consistent,
	  as well as removing redundant components from the path (for example, a
	  path of <literal>/a/b/c/../d/../../e</literal> will be normalised to
	  <literal>/a/e</literal>).
	</para>
	<para>
	  Once parsed, a URI can be resolved against a base URI if it is relative
	  using <citerefentry><refentrytitle><ulink url="uri_create_uri.3.html">uri_create_uri</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>,
	  and can be recomposed into a string representation using <citerefentry><refentrytitle><ulink url="uri_str.3.html">uri_str</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>.
	</para>	
  </refsect1>

  <refsect1>
	<title>Parameters</title>
	<variablelist>

	  <varlistentry>
		<term><parameter>uristr</parameter></term>
		<listitem>
		  <para>
			A string to parse as a URI or IRI.
		  </para>
		</listitem>
	  </varlistentry>

	  <varlistentry>
		<term><parameter>base</parameter></term>
		<listitem>
		  <para>
			An optional absolute base URI. If <parameter>base</parameter> is supplied but is not an absolute URI, the results are undefined.
		  </para>
		</listitem>
	  </varlistentry>
	  
	</variablelist>
  </refsect1>

  <refsect1>
	<title>Return value</title>
	<para>
	  If the URI was parsed successfully, <function>uri_create_str</function>
	  will return a new <type>URI</type> instance. If the URI could not be
	  parsed, or some other error occurs, <constant>NULL</constant> will
	  be returned and <varname>errno</varname> set accordingly.
	</para>
  </refsect1>

  <refsect1>
	<title>Diagnostics</title>
	<para>
	  In the event of an error ocurring, <varname>errno</varname> may be
	  set to one of the following values:
	</para>
	<variablelist>

	  <varlistentry>
		<term><constant>EINVAL</constant></term>
		<listitem>
		  <para>
			The URI was not well-formed and could not be parsed.
		  </para>
		</listitem>
	  </varlistentry>

	  <varlistentry>
		<term><constant>ENOMEM</constant></term>
		<listitem>
		  <para>
			A  memory allocation operation failed.
		  </para>
		</listitem>
	  </varlistentry>

	</variablelist>

  </refsect1>

  <refsect1>
	<title>Examples</title>
	<para>Parsing an absolute URI:</para>
	<programlisting language="c">
URI *uri;

uri = uri_create_str("http://example.com/sample", NULL);
	</programlisting>

	<para>
	  Parsing a relative URI, and resolving it against an absolute
	  base URI:
	</para>

	<programlisting language="c">
URI *base, *uri;

base = uri_create_str("http://example.com/sample", NULL);

/* The result would be as though the string being parsed had been:
 *    http://example.com/switch?toggle=1
 */
uri = uri_create_str("switch?toggle=1", base);
	</programlisting>
	
  </refsect1>

  <refsect1>
	<title>See also</title>
	<para>
	  <citerefentry><refentrytitle><ulink url="liburi.3.html">liburi</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>,
	  <citerefentry><refentrytitle><ulink url="uri_create_uri.3.html">uri_create_uri</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>,
	  <citerefentry><refentrytitle><ulink url="uri_destroy.3.html">uri_destroy</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle><ulink url="uri_absolute.3.html">uri_absolute</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle><ulink url="uri_str.3.html">uri_str</ulink></refentrytitle><manvolnum>3</manvolnum></citerefentry>.
	</para>
  </refsect1>
  
</refentry>