--- /dev/null
+<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+ This file is part of elogind.
+
+ Copyright 2014 Zbigniew Jędrzejewski-Szmek
+
+ elogind is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ elogind is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with elogind; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_bus_path_encode">
+
+ <refentryinfo>
+ <title>sd_bus_path_encode</title>
+ <productname>elogind</productname>
+
+ <authorgroup>
+ <author>
+ <contrib>A monkey with a typewriter</contrib>
+ <firstname>Zbigniew</firstname>
+ <surname>Jędrzejewski-Szmek</surname>
+ <email>zbyszek@in.waw.pl</email>
+ </author>
+ </authorgroup>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>sd_bus_path_encode</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_bus_path_encode</refname>
+ <refname>sd_bus_path_encode_many</refname>
+ <refname>sd_bus_path_decode</refname>
+ <refname>sd_bus_path_decode_many</refname>
+
+ <refpurpose>Convert an external identifier into an object path and back</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <elogind/sd-bus.h></funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_path_encode</function></funcdef>
+ <paramdef>const char *<parameter>prefix</parameter></paramdef>
+ <paramdef>const char *<parameter>external_id</parameter></paramdef>
+ <paramdef>char **<parameter>ret_path</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_path_encode_many</function></funcdef>
+ <paramdef>char **<parameter>out</parameter></paramdef>
+ <paramdef>const char *<parameter>path_template</parameter></paramdef>
+ <paramdef>...</paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_path_decode</function></funcdef>
+ <paramdef>const char *<parameter>path</parameter></paramdef>
+ <paramdef>const char *<parameter>prefix</parameter></paramdef>
+ <paramdef>char **<parameter>ret_external_id</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_path_decode_many</function></funcdef>
+ <paramdef>const char *<parameter>path</parameter></paramdef>
+ <paramdef>const char *<parameter>path_template</parameter></paramdef>
+ <paramdef>...</paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><function>sd_bus_path_encode()</function> and
+ <function>sd_bus_path_decode()</function> convert external
+ identifier strings into object paths and back. These functions are
+ useful to map application-specific string identifiers of any kind
+ into bus object paths in a simple, reversible and safe way.</para>
+
+ <para><function>sd_bus_path_encode()</function> takes a bus path
+ prefix and an external identifier string as arguments, plus a
+ place to store the returned bus path string. The bus path prefix
+ must be a valid bus path, starting with a slash
+ <literal>/</literal>, and not ending in one. The external
+ identifier string may be in any format, may be the empty string,
+ and has no restrictions on the charset — however, it must
+ always be <constant>NUL</constant>-terminated. The returned string
+ will be the concatenation of the bus path prefix plus an escaped
+ version of the external identifier string. This operation may be
+ reversed with <function>sd_bus_decode()</function>. It is
+ recommended to only use external identifiers that generally
+ require little escaping to be turned into valid bus path
+ identifiers (for example, by sticking to a 7-bit ASCII character
+ set), in order to ensure the resulting bus path is still short and
+ easily processed.</para>
+
+ <para><function>sd_bus_path_decode()</function> reverses the
+ operation of <function>sd_bus_path_encode()</function> and thus
+ regenerates an external identifier string from a bus path. It
+ takes a bus path and a prefix string, plus a place to store the
+ returned external identifier string. If the bus path does not
+ start with the specified prefix, 0 is returned and the returned
+ string is set to <constant>NULL</constant>. Otherwise, the
+ string following the prefix is unescaped and returned in the
+ external identifier string.</para>
+
+ <para>The escaping used will replace all characters which are
+ invalid in a bus object path by <literal>_</literal>, followed by a
+ hexadecimal value. As a special case, the empty string will be
+ replaced by a lone <literal>_</literal>.</para>
+
+ <para><function>sd_bus_path_encode_many()</function> works like
+ its counterpart <function>sd_bus_path_encode()</function>, but
+ takes a path template as argument and encodes multiple labels
+ according to its embedded directives. For each
+ <literal>%</literal> character found in the template, the caller
+ must provide a string via varargs, which will be encoded and
+ embedded at the position of the <literal>%</literal> character.
+ Any other character in the template is copied verbatim into the
+ encoded path.</para>
+
+ <para><function>sd_bus_path_decode_many()</function> does the
+ reverse of <function>sd_bus_path_encode_many()</function>. It
+ decodes the passed object path according to the given
+ path template. For each <literal>%</literal> character in the
+ template, the caller must provide an output storage
+ (<literal>char **</literal>) via varargs. The decoded label
+ will be stored there. Each <literal>%</literal> character will
+ only match the current label. It will never match across labels.
+ Furthermore, only a single directive is allowed per label.
+ If <literal>NULL</literal> is passed as output storage, the
+ label is verified but not returned to the caller.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para>On success, <function>sd_bus_path_encode()</function>
+ returns positive or 0, and a valid bus path in the return
+ argument. On success, <function>sd_bus_path_decode()</function>
+ returns a positive value if the prefixed matched, or 0 if it
+ did not. If the prefix matched, the external identifier is returned
+ in the return parameter. If it did not match, NULL is returned in
+ the return parameter. On failure, a negative errno-style error
+ number is returned by either function. The returned strings must
+ be
+ <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>'d
+ by the caller.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para><function>sd_bus_path_encode()</function> and
+ <function>sd_bus_path_decode()</function> are available as a
+ shared library, which can be compiled and linked to with the
+ <constant>libelogind</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ file.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <para>
+ <citerefentry><refentrytitle>elogind</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
~ianmdlvl / elogind.git / blobdiff