gsh/completion.py

   1 # This program is free software; you can redistribute it and/or modify
   2 # it under the terms of the GNU General Public License as published by
   3 # the Free Software Foundation; either version 2 of the License, or
   4 # (at your option) any later version.
   5 #
   6 # This program is distributed in the hope that it will be useful,
   7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 # GNU Library General Public License for more details.
  10 #
  11 # You should have received a copy of the GNU General Public License
  12 # along with this program; if not, write to the Free Software
  13 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  14 #
  15 # See the COPYING file for license information.
  16 #
  17 # Copyright (c) 2008 Guillaume Chazarain <guichaz@gmail.com>
  18
  19 import os
  20 import readline
  21
  22 def complete_local_absolute_path(path):
  23     if not path.startswith('/'):
  24         return []
  25     dirname, basename = os.path.split(path)
  26     if not dirname.endswith('/'):
  27         dirname += '/'
  28     paths = [dirname + p for p in os.listdir(dirname) if p.startswith(basename)]
  29     def get_suffix(p):
  30         if os.path.isdir(p):
  31             return '/'
  32         return ''
  33     paths = [p + get_suffix(p) for p in paths]
  34     return paths
  35
  36 def remove_dupes(words):
  37     added = set()
  38     results = list()
  39     for w in words:
  40         stripped = w.rstrip('/ ')
  41         if stripped not in added:
  42             added.add(stripped)
  43             results.append(w)
  44     return results
  45
  46 def read_commands_in_path():
  47     commands = set()
  48
  49     for path in (os.getenv('PATH') or '').split(':'):
  50         if path:
  51             try:
  52                 listing = os.listdir(path)
  53             except OSError:
  54                 pass
  55             else:
  56                 commands |= set(listing)
  57     return list(commands)
  58
  59 # All the words that have been typed in gsh. Used by the completion mechanism.
  60 history_words = set()
  61
  62 # When listing possible completions, the complete() function is called with
  63 # an increasing state parameter until it returns None. Cache the completion
  64 # list instead of regenerating it for each completion item.
  65 completion_results = None
  66
  67 # Commands in $PATH, used for the completion of the first word
  68 user_commands_in_path = read_commands_in_path()
  69
  70 def complete(text, state):
  71     """On tab press, return the next possible completion"""
  72     from gsh.control_commands_helpers import complete_control_command
  73     global completion_results
  74     if state == 0:
  75         line = readline.get_line_buffer()
  76         if line.startswith(':'):
  77             # Control command completion
  78             completion_results = complete_control_command(line, text)
  79         else:
  80             if line.startswith('!'):
  81                 dropped_exclam = True
  82                 text = text[1:]
  83             else:
  84                 dropped_exclam = False
  85             completion_results = []
  86             # Complete absolute paths
  87             completion_results += complete_local_absolute_path(text)
  88             # Complete from history
  89             l = len(text)
  90             completion_results += [w + ' ' for w in history_words if \
  91                                               len(w) > l and w.startswith(text)]
  92             if readline.get_begidx() == 0:
  93                 # Completing first word from $PATH
  94                 completion_results += [w + ' ' for w in user_commands_in_path \
  95                                            if len(w) > l and w.startswith(text)]
  96             completion_results = remove_dupes(completion_results)
  97             if dropped_exclam:
  98                 completion_results = ['!' + r for r in completion_results]
  99
 100     if state < len(completion_results):
 101         return completion_results[state]
 102     completion_results = None
 103
 104 def add_to_history(cmd):
 105     words = [w for w in cmd.split() if len(w) > 1]
 106     history_words.update(words)
 107     if len(history_words) > 10000:
 108         del history_words[:-10000]
 109
 110 def remove_last_history_item():
 111     """The user just typed a password..."""
 112     last = readline.get_current_history_length() - 1
 113     readline.remove_history_item(last)
 114
 115 def install_completion_handler():
 116     readline.set_completer(complete)
 117     readline.parse_and_bind('tab: complete')
 118     readline.set_completer_delims(' \t\n')
 119