wayland/doc/man/wl_display_connect.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<!--
  Written 2012 by David Herrmann <dh.herrmann@googlemail.com>
  Dedicated to the Public Domain
-->

<refentry id="wl_display_connect">
  <refentryinfo>
    <title>wl_display_connect</title>
    <productname>wayland-client</productname>
    <date>September 2012</date>
    <authorgroup>
      <author>
        <contrib>Developer</contrib>
        <firstname>David</firstname>
        <surname>Herrmann</surname>
        <email>dh.herrmann@googlemail.com</email>
      </author>
    </authorgroup>
  </refentryinfo>

  <refmeta>
    <refentrytitle>wl_display_connect</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>wl_display_connect</refname>
    <refname>wl_display_connect_to_fd</refname>
    <refpurpose>Connect to a Wayland socket</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <funcsynopsis>

      <funcsynopsisinfo>#include &lt;wayland-client.h&gt;</funcsynopsisinfo>

      <funcprototype>
        <funcdef>struct wl_display *<function>wl_display_connect</function></funcdef>
        <paramdef>const char *<parameter>name</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>struct wl_display *<function>wl_display_connect_to_fd</function></funcdef>
        <paramdef>int <parameter>fd</parameter></paramdef>
      </funcprototype>

    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>
    <para><function>wl_display_connect</function> connects to a Wayland socket
          that was previously opened by a Wayland server. The server socket must
          be placed in <envar>XDG_RUNTIME_DIR</envar> when <envar>WAYLAND_DISPLAY</envar>
	  (or <varname>name</varname>, see below) is a simple name, for this
	  function to find it. The server socket is also allowed to exist at an
	  arbitrary path; usage details follow. See below for compatibility issue
	  details.</para>

    <para>The <varname>name</varname> argument specifies the name of
          the socket or <constant>NULL</constant> to use the default (which is
          <constant>"wayland-0"</constant>). The environment variable
          <envar>WAYLAND_DISPLAY</envar> replaces the default value.

	  If <varname>name</varname> is an absolute path, then that path is used
	  as the Wayland socket to which the connection is attempted. Note that
	  in combination with the default-value behavior described above, this
	  implies that setting <envar>WAYLAND_DISPLAY</envar> to an absolute
	  path will implicitly cause <varname>name</varname> to take on that
	  absolute path if <varname>name</varname> is <constant>NULL</constant>.

          If <envar>WAYLAND_SOCKET</envar> is set, this function behaves like
          <function>wl_display_connect_to_fd</function> with the file-descriptor
          number taken from the environment variable.</para>

    <para>Support for interpreting <envar>WAYLAND_DISPLAY</envar> as an
          absolute path is a change in behavior compared to
          <function>wl_display_connect</function>'s behavior in versions
          1.14 and older of Wayland. It is no longer guaranteed in versions
          1.15 and higher that the Wayland socket chosen is equivalent to
          manually constructing a socket pathname by concatenating
          <envar>XDG_RUNTIME_DIR</envar> and <envar>WAYLAND_DISPLAY</envar>.
          Manual construction of the socket path must account for the
          possibility that <envar>WAYLAND_DISPLAY</envar> contains an absolute
          path.</para>

    <para><function>wl_display_connect_to_fd</function> connects to a Wayland
          socket with an explicit file-descriptor. The file-descriptor is passed
          as argument <varname>fd</varname>.</para>
  </refsect1>

  <refsect1>
    <title>Return Value</title>
    <para><function>wl_display_connect</function> and
          <function>wl_display_connect_to_fd</function> return a new display
          context object or NULL on failure. <varname>errno</varname> is set
          correspondingly.</para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>wayland-client</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>wl_display_disconnect</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>wl_display_iterate</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    </para>
  </refsect1>
</refentry>