mingw/info/gdb/Conditional-Init-Constructs.html

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  12 Node:<a name="Conditional%20Init%20Constructs">Conditional Init Constructs</a>,
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  19 <h4 class="subsection">Conditional Init Constructs</h4>
  20
  21    <p>Readline implements a facility similar in spirit to the conditional
  22 compilation features of the C preprocessor which allows key
  23 bindings and variable settings to be performed as the result
  24 of tests.  There are four parser directives used.
  25
  26      <dl>
  27 <dt><code>$if</code>
  28      <dd>The <code>$if</code> construct allows bindings to be made based on the
  29 editing mode, the terminal being used, or the application using
  30 Readline.  The text of the test extends to the end of the line;
  31 no characters are required to isolate it.
  32
  33           <dl>
  34 <dt><code>mode</code>
  35           <dd>The <code>mode=</code> form of the <code>$if</code> directive is used to test
  36 whether Readline is in <code>emacs</code> or <code>vi</code> mode.
  37 This may be used in conjunction
  38 with the <code>set keymap</code> command, for instance, to set bindings in
  39 the <code>emacs-standard</code> and <code>emacs-ctlx</code> keymaps only if
  40 Readline is starting out in <code>emacs</code> mode.
  41
  42           <br><dt><code>term</code>
  43           <dd>The <code>term=</code> form may be used to include terminal-specific
  44 key bindings, perhaps to bind the key sequences output by the
  45 terminal's function keys.  The word on the right side of the
  46 <code>=</code> is tested against both the full name of the terminal and
  47 the portion of the terminal name before the first <code>-</code>.  This
  48 allows <code>sun</code> to match both <code>sun</code> and <code>sun-cmd</code>,
  49 for instance.
  50
  51           <br><dt><code>application</code>
  52           <dd>The <var>application</var> construct is used to include
  53 application-specific settings.  Each program using the Readline
  54 library sets the <var>application name</var>, and you can test for
  55 a particular value.
  56 This could be used to bind key sequences to functions useful for
  57 a specific program.  For instance, the following command adds a
  58 key sequence that quotes the current or previous word in Bash:
  59           <pre class="example">               $if Bash
  60                # Quote the current or previous word
  61                "\C-xq": "\eb\"\ef\""
  62                $endif
  63                </pre>
  64           </dl>
  65
  66      <br><dt><code>$endif</code>
  67      <dd>This command, as seen in the previous example, terminates an
  68 <code>$if</code> command.
  69
  70      <br><dt><code>$else</code>
  71      <dd>Commands in this branch of the <code>$if</code> directive are executed if
  72 the test fails.
  73
  74      <br><dt><code>$include</code>
  75      <dd>This directive takes a single filename as an argument and reads commands
  76 and bindings from that file.
  77 For example, the following directive reads from <code>/etc/inputrc</code>:
  78      <pre class="example">          $include /etc/inputrc
  79           </pre>
  80      </dl>
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