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 glob
  20 import os
  21 import readline
  22
  23 from gsh.control_commands_helpers import complete_control_command
  24 from gsh.control_commands_helpers import expand_local_path
  25
  26 def complete_local_path(path):
  27     def get_suffix(p):
  28         if os.path.isdir(p):
  29             return '/'
  30         return ''
  31     path = expand_local_path(path)
  32     paths = [p + get_suffix(p) for p in glob.glob(path + '*')]
  33     return paths
  34
  35 def remove_dupes(words):
  36     added = set()
  37     results = list()
  38     for w in words:
  39         stripped = w.rstrip('/ ')
  40         if stripped not in added:
  41             added.add(stripped)
  42             results.append(w)
  43     return results
  44
  45 def read_commands_in_path():
  46     commands = set()
  47
  48     for path in (os.getenv('PATH') or '').split(':'):
  49         if path:
  50             try:
  51                 listing = os.listdir(path)
  52             except OSError:
  53                 pass
  54             else:
  55                 commands |= set(listing)
  56     return list(commands)
  57
  58 # All the words that have been typed in gsh. Used by the completion mechanism.
  59 history_words = set()
  60
  61 # When listing possible completions, the complete() function is called with
  62 # an increasing state parameter until it returns None. Cache the completion
  63 # list instead of regenerating it for each completion item.
  64 completion_results = None
  65
  66 # Commands in $PATH, used for the completion of the first word
  67 user_commands_in_path = read_commands_in_path()
  68
  69 try:
  70     import ctypes.util
  71     lib_readline = ctypes.cdll.LoadLibrary(ctypes.util.find_library("readline"))
  72     rl_completion_append_character = ctypes.c_char.in_dll(lib_readline,
  73                                                "rl_completion_append_character")
  74 except Exception:
  75     class rl_completion_append_character:
  76         pass
  77
  78
  79 def complete(text, state):
  80     """On tab press, return the next possible completion"""
  81     rl_completion_append_character.value = '\0'
  82     global completion_results
  83     if state == 0:
  84         line = readline.get_line_buffer()
  85         if line.startswith(':'):
  86             # Control command completion
  87             completion_results = complete_control_command(line, text)
  88         else:
  89             if line.startswith('!') and text and line.startswith(text):
  90                 dropped_exclam = True
  91                 text = text[1:]
  92             else:
  93                 dropped_exclam = False
  94             completion_results = []
  95             # Complete local paths
  96             completion_results += complete_local_path(text)
  97             # Complete from history
  98             l = len(text)
  99             completion_results += [w + ' ' for w in history_words if \
 100                                               len(w) > l and w.startswith(text)]
 101             if readline.get_begidx() == 0:
 102                 # Completing first word from $PATH
 103                 completion_results += [w + ' ' for w in user_commands_in_path \
 104                                            if len(w) > l and w.startswith(text)]
 105             completion_results = remove_dupes(completion_results)
 106             if dropped_exclam:
 107                 completion_results = ['!' + r for r in completion_results]
 108
 109     if state < len(completion_results):
 110         return completion_results[state]
 111     completion_results = None
 112
 113 def add_to_history(cmd):
 114     words = [w for w in cmd.split() if len(w) > 1]
 115     history_words.update(words)
 116     if len(history_words) > 10000:
 117         del history_words[:-10000]
 118
 119 def remove_last_history_item():
 120     """The user just typed a password..."""
 121     last = readline.get_current_history_length() - 1
 122     readline.remove_history_item(last)
 123
 124 def install_completion_handler():
 125     readline.set_completer(complete)
 126     readline.parse_and_bind('tab: complete')
 127     readline.set_completer_delims(' \t\n')
 128