wine/documentation/consoles.sgml

  <chapter id="consoles">
    <title>Consoles in Wine</title>

    <sect1 id="wine-consoles">
      <title>Consoles</title>

      <para>
        Written by &name-john-richardson; <email>&email-john-richardson;</email>
        Maintained by &name-joseph-pranevich; <email>&email-joseph-pranevich;</email>
      </para>
      <para>
        (Extracted from <filename>wine/documentation/console</filename>)
      </para>

      <sect2>
        <title>Console - First Pass</title>

        <para>
          Consoles are just xterms created with the
          <parameter>-Sxxn</parameter> switch. A
          <systemitem>pty</systemitem> is opened and the master goes
          to the <filename>xterm</filename> side and the slave is held
          by the wine side.  The console itself is turned into a few
          <type>HANDLE32</type>s and is set to the
          <varname>STD_*_HANDLES</varname>.
        </para>
        <para>
          It is possible to use the <function>WriteFile</function> and
          <function>ReadFile</function> commands to write to a win32
          console.  To accomplish this, all <type>K32OBJ</type>s that
          support I/O have a read and write function pointer. So,
          <function>WriteFile</function> calls
          <function>K32OBJ_WriteFile</function> which calls the
          <type>K32OBJ</type>'s write function pointer, which then
          finally calls <function>write</function>.
        </para>
        <para>
          <emphasis>[this paragraph is now out of date]</emphasis> If
          the command line console is to be inherited or a process
          inherits its parent's console (-- can that happen???), the
          console is created at process init time via
          <function>PROCESS_InheritConsole</function>. The
          <literal>0</literal>, <literal>1</literal>, and
          <literal>2</literal> file descriptors are duped to be the
          <varname>STD_*_HANDLES</varname> in this case.  Also in this
          case a flag is set to indicate that the console comes from
          the parent process or command line.
        </para>
        <para>
          If a process doesn't have a console at all, its
          <varname>pdb-&gt;console</varname> is set to
          <constant>NULL</constant>.  This helps indicate when it is
          possible to create a new console (via
          <function>AllocConsole</function>).
        </para>
        <para>
          When <function>FreeConsole</function> is called, all handles that the process has
          open to the console are closed.  Like most <type>K32OBJ</type>s, if the
          console's refcount reaches zero, its <type>K32OBJ</type> destroy function
          is called.  The destroy kills the xterm if one was open.
        </para>
        <para>
          Also like most k32 objects, we assume that
          (<type>K32OBJ</type>) header is the first field so the
          casting (from <type>K32OBJ*</type>to <type>CONSOLE*</type>)
          works correctly.
        </para>
        <para>
          <function>FreeConsole</function> is called on process exit
          (in <function>ExitProcess</function>) if
          <varname>pdb-&gt;console</varname> is not
          <constant>NULL</constant>.
        </para>
      </sect2>

      <sect2>
        <title>BUGS</title>

        <para>
          Console processes do not inherit their parent's handles.  I
          think there needs to be two cases, one where they have to
          inherit the <filename>stdin</filename> /
          <filename>stdout</filename> / <filename>stderr</filename>
          from unix, and one where they have to inherit from another
          windows app.
        </para>
        <para>
          <function>SetConsoleMode</function> -- UNIX only has
          <constant>ICANON</constant> and various
          <constant>ECHO</constant>s to play around with for
          processing input.  Win32 has line-at-a-time processing,
          character processing, and echo. I'm putting together an
          intermediate driver that will handle this (and hopefully
          won't be any more buggy than the NT4 console
          implementation).
        </para>
      </sect2>

      <sect2>
        <title>Experimentation</title>

        <para>
          experimentation with NT4 yields that:
        </para>

        <variablelist>
          <varlistentry>
            <term><function>WriteFile</function></term>
            <listitem>
              <itemizedlist>
                <listitem>
                  <para>does not truncate file on 0 length write</para>
                </listitem>
                <listitem>
                  <para>
                    0 length write or error on write changes
                    <varname>numcharswritten</varname> to
                    <literal>0</literal>
                  </para>
                </listitem>
                <listitem>
                  <para>0 length write returns <constant>TRUE</constant></para>
                </listitem>
                <listitem>
                  <para>works with console handles</para>
                </listitem>
              </itemizedlist>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><function>_lwrite</function></term>
            <listitem>
              <itemizedlist>
                <listitem>
                  <para>does truncate/expand file at current position on 0 length write</para>
                </listitem>
                <listitem>
                  <para>returns 0 on a zero length write</para>
                </listitem>
                <listitem>
                  <para>works with console handles (typecasted)</para>
                </listitem>
              </itemizedlist>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><function>WriteConsole</function></term>
            <listitem>
              <itemizedlist>
                <listitem>
                  <para>expects only console handles</para>
                </listitem>
              </itemizedlist>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><function>SetFilePointer</function></term>
            <listitem>
              <itemizedlist>
                <listitem>
                  <para>returns -1 (err 6) when used with a console handle</para>
                </listitem>
              </itemizedlist>
            </listitem>
          </varlistentry>
          <varlistentry>
            <term><function>FreeConsole</function></term>
            <listitem>
              <itemizedlist>
                <listitem>
                  <para>
                    even when all the handles to it are freed, the
                    win32 console stays visible, the only way I could
                    find to free it was via the <function>FreeConsole</function>
                  </para>
                </listitem>
              </itemizedlist>
            </listitem>
          </varlistentry>
        </variablelist>

        <para>
          Is it possible to interrupt win32's
          <function>FileWrite</function>?  I'm not sure. It may not be
          possible to interrupt any system calls.
        </para>
      </sect2>

      <sect2>
        <title>DOS (Generic) Console Support</title>

        <sect3>
          <title>I. Command Line Configuration</title>

          <para>
            DOS consoles must be configured either on the command line
            or in a dot resource file (<filename>.console</filename>).
            A typical configuration consists of a string of driver
            keywords separated by plus ('+') signs. To change the
            configuration on the command-line, use the
            <parameter>-console</parameter> switch.
          </para>
          <para>
            For example:
          </para>
          <screen>
wine -console ncurses+xterm &lt;application&gt;
          </screen>
          <para>
            Possible drivers:
          </para>

          <variablelist>
            <varlistentry>
              <term>tty:</term>
              <listitem>
                <para>Generic text-only support. Supports redirection.</para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>ncurses:</term>
              <listitem>
                <para>Full-screen graphical support with color.</para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>xterm:</term>
              <listitem>
                <para>
                  Load a new window to display the console in. Also
                  supports resizing windows.
                </para>
              </listitem>
            </varlistentry>
          </variablelist>
        </sect3>

        <sect3>
          <title>II. wine config file configuration</title>

          <para>
            In the wine config file, you can create
            a section called [console] that contains configuration
            options that are respected by the assorted console
            drivers.
          </para>
          <para>
            Current Options:
          </para>

          <variablelist>
            <varlistentry>
              <term>XtermProg=&lt;program&gt;</term>
              <listitem>
                <para>
                  Use this program instead of
                  <command>xterm</command>. This eliminates the need
                  for a recompile. See the table below for a
                  comparison of various terminals.
                </para>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>InitialRows=&lt;number&gt;</term>
              <listitem>
                <para>
                  Attempt to start all drivers with this number of
                  rows. This causes xterms to be resized, for
                  instance.
                </para>
                <note>
                  <para>
                    This information is passed on the command-line
                    with the <parameter>-g</parameter> switch.
                  </para>
                </note>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>InitialColumns=&lt;number&gt;</term>
              <listitem>
                <para>
                  Attempt to start all drivers with this number of
                  columns. This causes xterms to be resized, for
                  instance.
                </para>
                <note>
                  <para>
                    This information is passed on the command-line
                    with the <parameter>-g</parameter> switch.
                  </para>
                </note>
              </listitem>
            </varlistentry>
            <varlistentry>
              <term>TerminalType=&lt;name&gt;</term>
              <listitem>
                <para>
                  Tell any driver that is interested (ncurses) which
                  termcap and/or terminfo type to use. The default is
                  xterm which is appropriate for most uses.
                  <command>nxterm</command> may give you better
                  support if you use that terminal. This can also be
                  changed to "linux" (or "console" on older systems)
                  if you manage to hack the ability to write to the
                  console into this driver.
                </para>
              </listitem>
            </varlistentry>
          </variablelist>
        </sect3>

        <sect3>
          <title>III. Terminal Types</title>

          <para>
            There are a large number of potential terminals that can
            be used with Wine, depending on what you are trying to do.
            Unfortunately, I am still looking for the "best" driver
            combination.
          </para>
          <note>
            <para>
              'slave' is required for use in Wine, currently.
            </para>
          </note>

          <informaltable>
            <tgroup cols="4">
              <thead>
                <row>
                  <entry>Program</entry>
                  <entry>Color?</entry>
                  <entry>Resizing?</entry>
                  <entry>Slave?</entry>
                </row>
              </thead>
              <tfoot>
                <row>
                  <entry>(linux console)</entry>
                  <entry>Y</entry>
                  <entry>N</entry>
                  <entry>?</entry>
                </row>
              </tfoot>
              <tbody>
                <row>
                  <entry>xterm</entry>
                  <entry>N</entry>
                  <entry>Y</entry>
                  <entry>Y</entry>
                </row>
                <row>
                  <entry>nxterm</entry>
                  <entry>Y</entry>
                  <entry>N</entry>
                  <entry>Y</entry>
                </row>
                <row>
                  <entry>rxvt</entry>
                  <entry>Y</entry>
                  <entry>?</entry>
                  <entry>N</entry>
                </row>
              </tbody>
            </tgroup>
          </informaltable>

          <para>
            As X terminals typically use a 24x80 screen resolution
            rather than the typical 25x80 one, it is necessary to
            resize the screen to allow a DOS program to work
            full-screen. There is a wine config file
            option to work around this in some cases but run-time
            resizing will be disabled.
          </para>
        </sect3>
      </sect2>
    </sect1>
  </chapter>

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