Edit File: readline.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>16.8. readline — GNU readline interface — Python v2.6.6 documentation</title> <link rel="stylesheet" href="../_static/default.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript"> var DOCUMENTATION_OPTIONS = { URL_ROOT: '../', VERSION: '2.6.6', COLLAPSE_MODINDEX: false, FILE_SUFFIX: '.html', HAS_SOURCE: true }; </script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python v2.6.6 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="top" title="Python v2.6.6 documentation" href="../index.html" /> <link rel="up" title="16. Optional Operating System Services" href="someos.html" /> <link rel="next" title="16.9. rlcompleter — Completion function for GNU readline" href="rlcompleter.html" /> <link rel="prev" title="16.7. mmap — Memory-mapped file support" href="mmap.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> </head> <body> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../modindex.html" title="Global Module Index" accesskey="M">modules</a> |</li> <li class="right" > <a href="rlcompleter.html" title="16.9. rlcompleter — Completion function for GNU readline" accesskey="N">next</a> |</li> <li class="right" > <a href="mmap.html" title="16.7. mmap — Memory-mapped file support" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="../index.html">Python v2.6.6 documentation</a> »</li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="someos.html" accesskey="U">16. Optional Operating System Services</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-readline"> <h1>16.8. <tt class="xref docutils literal"><span class="pre">readline</span></tt> — GNU readline interface<a class="headerlink" href="#module-readline" title="Permalink to this headline">¶</a></h1> <p><em>Platforms: </em>Unix</p> <p>The <tt class="xref docutils literal"><span class="pre">readline</span></tt> module defines a number of functions to facilitate completion and reading/writing of history files from the Python interpreter. This module can be used directly or via the <a title="Python identifier completion, suitable for the GNU readline library." class="reference external" href="rlcompleter.html#module-rlcompleter"><tt class="xref docutils literal"><span class="pre">rlcompleter</span></tt></a> module. Settings made using this module affect the behaviour of both the interpreter’s interactive prompt and the prompts offered by the <a title="raw_input" class="reference external" href="functions.html#raw_input"><tt class="xref docutils literal"><span class="pre">raw_input()</span></tt></a> and <a title="input" class="reference external" href="functions.html#input"><tt class="xref docutils literal"><span class="pre">input()</span></tt></a> built-in functions.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p>On MacOS X the <tt class="xref docutils literal"><span class="pre">readline</span></tt> module can be implemented using the <tt class="docutils literal"><span class="pre">libedit</span></tt> library instead of GNU readline.</p> <p class="last">The configuration file for <tt class="docutils literal"><span class="pre">libedit</span></tt> is different from that of GNU readline. If you programmaticly load configuration strings you can check for the text “libedit” in <tt class="xref docutils literal"><span class="pre">readline.__doc__</span></tt> to differentiate between GNU readline and libedit.</p> </div> <p>The <tt class="xref docutils literal"><span class="pre">readline</span></tt> module defines the following functions:</p> <dl class="function"> <dt id="readline.parse_and_bind"> <tt class="descclassname">readline.</tt><tt class="descname">parse_and_bind</tt><big>(</big><em>string</em><big>)</big><a class="headerlink" href="#readline.parse_and_bind" title="Permalink to this definition">¶</a></dt> <dd>Parse and execute single line of a readline init file.</dd></dl> <dl class="function"> <dt id="readline.get_line_buffer"> <tt class="descclassname">readline.</tt><tt class="descname">get_line_buffer</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_line_buffer" title="Permalink to this definition">¶</a></dt> <dd>Return the current contents of the line buffer.</dd></dl> <dl class="function"> <dt id="readline.insert_text"> <tt class="descclassname">readline.</tt><tt class="descname">insert_text</tt><big>(</big><em>string</em><big>)</big><a class="headerlink" href="#readline.insert_text" title="Permalink to this definition">¶</a></dt> <dd>Insert text into the command line.</dd></dl> <dl class="function"> <dt id="readline.read_init_file"> <tt class="descclassname">readline.</tt><tt class="descname">read_init_file</tt><big>(</big><span class="optional">[</span><em>filename</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.read_init_file" title="Permalink to this definition">¶</a></dt> <dd>Parse a readline initialization file. The default filename is the last filename used.</dd></dl> <dl class="function"> <dt id="readline.read_history_file"> <tt class="descclassname">readline.</tt><tt class="descname">read_history_file</tt><big>(</big><span class="optional">[</span><em>filename</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.read_history_file" title="Permalink to this definition">¶</a></dt> <dd>Load a readline history file. The default filename is <tt class="docutils literal"><span class="pre">~/.history</span></tt>.</dd></dl> <dl class="function"> <dt id="readline.write_history_file"> <tt class="descclassname">readline.</tt><tt class="descname">write_history_file</tt><big>(</big><span class="optional">[</span><em>filename</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.write_history_file" title="Permalink to this definition">¶</a></dt> <dd>Save a readline history file. The default filename is <tt class="docutils literal"><span class="pre">~/.history</span></tt>.</dd></dl> <dl class="function"> <dt id="readline.clear_history"> <tt class="descclassname">readline.</tt><tt class="descname">clear_history</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.clear_history" title="Permalink to this definition">¶</a></dt> <dd><p>Clear the current history. (Note: this function is not available if the installed version of GNU readline doesn’t support it.)</p> <p class="versionadded"> <span class="versionmodified">New in version 2.4.</span></p> </dd></dl> <dl class="function"> <dt id="readline.get_history_length"> <tt class="descclassname">readline.</tt><tt class="descname">get_history_length</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_history_length" title="Permalink to this definition">¶</a></dt> <dd>Return the desired length of the history file. Negative values imply unlimited history file size.</dd></dl> <dl class="function"> <dt id="readline.set_history_length"> <tt class="descclassname">readline.</tt><tt class="descname">set_history_length</tt><big>(</big><em>length</em><big>)</big><a class="headerlink" href="#readline.set_history_length" title="Permalink to this definition">¶</a></dt> <dd>Set the number of lines to save in the history file. <a title="readline.write_history_file" class="reference internal" href="#readline.write_history_file"><tt class="xref docutils literal"><span class="pre">write_history_file()</span></tt></a> uses this value to truncate the history file when saving. Negative values imply unlimited history file size.</dd></dl> <dl class="function"> <dt id="readline.get_current_history_length"> <tt class="descclassname">readline.</tt><tt class="descname">get_current_history_length</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_current_history_length" title="Permalink to this definition">¶</a></dt> <dd><p>Return the number of lines currently in the history. (This is different from <a title="readline.get_history_length" class="reference internal" href="#readline.get_history_length"><tt class="xref docutils literal"><span class="pre">get_history_length()</span></tt></a>, which returns the maximum number of lines that will be written to a history file.)</p> <p class="versionadded"> <span class="versionmodified">New in version 2.3.</span></p> </dd></dl> <dl class="function"> <dt id="readline.get_history_item"> <tt class="descclassname">readline.</tt><tt class="descname">get_history_item</tt><big>(</big><em>index</em><big>)</big><a class="headerlink" href="#readline.get_history_item" title="Permalink to this definition">¶</a></dt> <dd><p>Return the current contents of history item at <em>index</em>.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.3.</span></p> </dd></dl> <dl class="function"> <dt id="readline.remove_history_item"> <tt class="descclassname">readline.</tt><tt class="descname">remove_history_item</tt><big>(</big><em>pos</em><big>)</big><a class="headerlink" href="#readline.remove_history_item" title="Permalink to this definition">¶</a></dt> <dd><p>Remove history item specified by its position from the history.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.4.</span></p> </dd></dl> <dl class="function"> <dt id="readline.replace_history_item"> <tt class="descclassname">readline.</tt><tt class="descname">replace_history_item</tt><big>(</big><em>pos</em>, <em>line</em><big>)</big><a class="headerlink" href="#readline.replace_history_item" title="Permalink to this definition">¶</a></dt> <dd><p>Replace history item specified by its position with the given line.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.4.</span></p> </dd></dl> <dl class="function"> <dt id="readline.redisplay"> <tt class="descclassname">readline.</tt><tt class="descname">redisplay</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.redisplay" title="Permalink to this definition">¶</a></dt> <dd><p>Change what’s displayed on the screen to reflect the current contents of the line buffer.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.3.</span></p> </dd></dl> <dl class="function"> <dt id="readline.set_startup_hook"> <tt class="descclassname">readline.</tt><tt class="descname">set_startup_hook</tt><big>(</big><span class="optional">[</span><em>function</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.set_startup_hook" title="Permalink to this definition">¶</a></dt> <dd>Set or remove the startup_hook function. If <em>function</em> is specified, it will be used as the new startup_hook function; if omitted or <tt class="xref docutils literal"><span class="pre">None</span></tt>, any hook function already installed is removed. The startup_hook function is called with no arguments just before readline prints the first prompt.</dd></dl> <dl class="function"> <dt id="readline.set_pre_input_hook"> <tt class="descclassname">readline.</tt><tt class="descname">set_pre_input_hook</tt><big>(</big><span class="optional">[</span><em>function</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.set_pre_input_hook" title="Permalink to this definition">¶</a></dt> <dd>Set or remove the pre_input_hook function. If <em>function</em> is specified, it will be used as the new pre_input_hook function; if omitted or <tt class="xref docutils literal"><span class="pre">None</span></tt>, any hook function already installed is removed. The pre_input_hook function is called with no arguments after the first prompt has been printed and just before readline starts reading input characters.</dd></dl> <dl class="function"> <dt id="readline.set_completer"> <tt class="descclassname">readline.</tt><tt class="descname">set_completer</tt><big>(</big><span class="optional">[</span><em>function</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.set_completer" title="Permalink to this definition">¶</a></dt> <dd>Set or remove the completer function. If <em>function</em> is specified, it will be used as the new completer function; if omitted or <tt class="xref docutils literal"><span class="pre">None</span></tt>, any completer function already installed is removed. The completer function is called as <tt class="docutils literal"><span class="pre">function(text,</span> <span class="pre">state)</span></tt>, for <em>state</em> in <tt class="docutils literal"><span class="pre">0</span></tt>, <tt class="docutils literal"><span class="pre">1</span></tt>, <tt class="docutils literal"><span class="pre">2</span></tt>, ..., until it returns a non-string value. It should return the next possible completion starting with <em>text</em>.</dd></dl> <dl class="function"> <dt id="readline.get_completer"> <tt class="descclassname">readline.</tt><tt class="descname">get_completer</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_completer" title="Permalink to this definition">¶</a></dt> <dd><p>Get the completer function, or <tt class="xref docutils literal"><span class="pre">None</span></tt> if no completer function has been set.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.3.</span></p> </dd></dl> <dl class="function"> <dt id="readline.get_completion_type"> <tt class="descclassname">readline.</tt><tt class="descname">get_completion_type</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_completion_type" title="Permalink to this definition">¶</a></dt> <dd><p>Get the type of completion being attempted.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> <dl class="function"> <dt id="readline.get_begidx"> <tt class="descclassname">readline.</tt><tt class="descname">get_begidx</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_begidx" title="Permalink to this definition">¶</a></dt> <dd>Get the beginning index of the readline tab-completion scope.</dd></dl> <dl class="function"> <dt id="readline.get_endidx"> <tt class="descclassname">readline.</tt><tt class="descname">get_endidx</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_endidx" title="Permalink to this definition">¶</a></dt> <dd>Get the ending index of the readline tab-completion scope.</dd></dl> <dl class="function"> <dt id="readline.set_completer_delims"> <tt class="descclassname">readline.</tt><tt class="descname">set_completer_delims</tt><big>(</big><em>string</em><big>)</big><a class="headerlink" href="#readline.set_completer_delims" title="Permalink to this definition">¶</a></dt> <dd>Set the readline word delimiters for tab-completion.</dd></dl> <dl class="function"> <dt id="readline.get_completer_delims"> <tt class="descclassname">readline.</tt><tt class="descname">get_completer_delims</tt><big>(</big><big>)</big><a class="headerlink" href="#readline.get_completer_delims" title="Permalink to this definition">¶</a></dt> <dd>Get the readline word delimiters for tab-completion.</dd></dl> <dl class="function"> <dt id="readline.set_completion_display_matches_hook"> <tt class="descclassname">readline.</tt><tt class="descname">set_completion_display_matches_hook</tt><big>(</big><span class="optional">[</span><em>function</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#readline.set_completion_display_matches_hook" title="Permalink to this definition">¶</a></dt> <dd><p>Set or remove the completion display function. If <em>function</em> is specified, it will be used as the new completion display function; if omitted or <tt class="xref docutils literal"><span class="pre">None</span></tt>, any completion display function already installed is removed. The completion display function is called as <tt class="docutils literal"><span class="pre">function(substitution,</span> <span class="pre">[matches],</span> <span class="pre">longest_match_length)</span></tt> once each time matches need to be displayed.</p> <p class="versionadded"> <span class="versionmodified">New in version 2.6.</span></p> </dd></dl> <dl class="function"> <dt id="readline.add_history"> <tt class="descclassname">readline.</tt><tt class="descname">add_history</tt><big>(</big><em>line</em><big>)</big><a class="headerlink" href="#readline.add_history" title="Permalink to this definition">¶</a></dt> <dd>Append a line to the history buffer, as if it was the last line typed.</dd></dl> <div class="admonition-see-also admonition seealso"> <p class="first admonition-title">See also</p> <dl class="last docutils"> <dt>Module <a title="Python identifier completion, suitable for the GNU readline library." class="reference external" href="rlcompleter.html#module-rlcompleter"><tt class="xref docutils literal"><span class="pre">rlcompleter</span></tt></a></dt> <dd>Completion of Python identifiers at the interactive prompt.</dd> </dl> </div> <div class="section" id="example"> <span id="readline-example"></span><h2>16.8.1. Example<a class="headerlink" href="#example" title="Permalink to this headline">¶</a></h2> <p>The following example demonstrates how to use the <tt class="xref docutils literal"><span class="pre">readline</span></tt> module’s history reading and writing functions to automatically load and save a history file named <tt class="docutils literal"><span class="pre">.pyhist</span></tt> from the user’s home directory. The code below would normally be executed automatically during interactive sessions from the user’s <span class="target" id="index-521"></span><a class="reference external" href="../using/cmdline.html#envvar-PYTHONSTARTUP"><strong class="xref">PYTHONSTARTUP</strong></a> file.</p> <div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">os</span> <span class="n">histfile</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">os</span><span class="o">.</span><span class="n">environ</span><span class="p">[</span><span class="s">"HOME"</span><span class="p">],</span> <span class="s">".pyhist"</span><span class="p">)</span> <span class="k">try</span><span class="p">:</span> <span class="n">readline</span><span class="o">.</span><span class="n">read_history_file</span><span class="p">(</span><span class="n">histfile</span><span class="p">)</span> <span class="k">except</span> <span class="ne">IOError</span><span class="p">:</span> <span class="k">pass</span> <span class="kn">import</span> <span class="nn">atexit</span> <span class="n">atexit</span><span class="o">.</span><span class="n">register</span><span class="p">(</span><span class="n">readline</span><span class="o">.</span><span class="n">write_history_file</span><span class="p">,</span> <span class="n">histfile</span><span class="p">)</span> <span class="k">del</span> <span class="n">os</span><span class="p">,</span> <span class="n">histfile</span> </pre></div> </div> <p>The following example extends the <a title="code.InteractiveConsole" class="reference external" href="code.html#code.InteractiveConsole"><tt class="xref docutils literal"><span class="pre">code.InteractiveConsole</span></tt></a> class to support history save/restore.</p> <div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">code</span> <span class="kn">import</span> <span class="nn">readline</span> <span class="kn">import</span> <span class="nn">atexit</span> <span class="kn">import</span> <span class="nn">os</span> <span class="k">class</span> <span class="nc">HistoryConsole</span><span class="p">(</span><span class="n">code</span><span class="o">.</span><span class="n">InteractiveConsole</span><span class="p">):</span> <span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="nb">locals</span><span class="o">=</span><span class="bp">None</span><span class="p">,</span> <span class="n">filename</span><span class="o">=</span><span class="s">"<console>"</span><span class="p">,</span> <span class="n">histfile</span><span class="o">=</span><span class="n">os</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">expanduser</span><span class="p">(</span><span class="s">"~/.console-history"</span><span class="p">)):</span> <span class="n">code</span><span class="o">.</span><span class="n">InteractiveConsole</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="nb">locals</span><span class="p">,</span> <span class="n">filename</span><span class="p">)</span> <span class="bp">self</span><span class="o">.</span><span class="n">init_history</span><span class="p">(</span><span class="n">histfile</span><span class="p">)</span> <span class="k">def</span> <span class="nf">init_history</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">histfile</span><span class="p">):</span> <span class="n">readline</span><span class="o">.</span><span class="n">parse_and_bind</span><span class="p">(</span><span class="s">"tab: complete"</span><span class="p">)</span> <span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">readline</span><span class="p">,</span> <span class="s">"read_history_file"</span><span class="p">):</span> <span class="k">try</span><span class="p">:</span> <span class="n">readline</span><span class="o">.</span><span class="n">read_history_file</span><span class="p">(</span><span class="n">histfile</span><span class="p">)</span> <span class="k">except</span> <span class="ne">IOError</span><span class="p">:</span> <span class="k">pass</span> <span class="n">atexit</span><span class="o">.</span><span class="n">register</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">save_history</span><span class="p">,</span> <span class="n">histfile</span><span class="p">)</span> <span class="k">def</span> <span class="nf">save_history</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">histfile</span><span class="p">):</span> <span class="n">readline</span><span class="o">.</span><span class="n">write_history_file</span><span class="p">(</span><span class="n">histfile</span><span class="p">)</span> </pre></div> </div> </div> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference external" href="#">16.8. <tt class="docutils literal"><span class="pre">readline</span></tt> — GNU readline interface</a><ul> <li><a class="reference external" href="#example">16.8.1. Example</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="mmap.html" title="previous chapter">16.7. <tt class="docutils literal docutils literal docutils literal"><span class="pre">mmap</span></tt> — Memory-mapped file support</a></p> <h4>Next topic</h4> <p class="topless"><a href="rlcompleter.html" title="next chapter">16.9. <tt class="docutils literal docutils literal"><span class="pre">rlcompleter</span></tt> — Completion function for GNU readline</a></p> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li><a href="../_sources/library/readline.txt" rel="nofollow">Show Source</a></li> </ul> <div id="searchbox" style="display: none"> <h3>Quick search</h3> <form class="search" action="../search.html" method="get"> <input type="text" name="q" size="18" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> <p class="searchtip" style="font-size: 90%"> Enter search terms or a module, class or function name. </p> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="related"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../modindex.html" title="Global Module Index" >modules</a> |</li> <li class="right" > <a href="rlcompleter.html" title="16.9. rlcompleter — Completion function for GNU readline" >next</a> |</li> <li class="right" > <a href="mmap.html" title="16.7. mmap — Memory-mapped file support" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="../index.html">Python v2.6.6 documentation</a> »</li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="someos.html" >16. Optional Operating System Services</a> »</li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 1990-2011, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="http://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Jul 20, 2011. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 0.6.6. </div> </body> </html>
Back to File Manager