ranger/ext/shell_escape.py

   1 # Copyright (C) 2009, 2010, 2011  Roman Zimbelmann <romanz@lavabit.com>
   2 #
   3 # This program is free software: you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation, either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 """
  17 Functions to escape metacharacters of arguments for shell commands.
  18 """
  19
  20 META_CHARS = (' ', "'", '"', '`', '&', '|', ';',
  21                 '$', '!', '(', ')', '[', ']', '<', '>', '\t')
  22 UNESCAPABLE = set(map(chr, list(range(9)) + list(range(10, 32)) \
  23                 + list(range(127, 256))))
  24 META_DICT = dict([(mc, '\\' + mc) for mc in META_CHARS])
  25
  26 def shell_quote(string):
  27         """Escapes by quoting"""
  28         return "'" + str(string).replace("'", "'\\''") + "'"
  29
  30 def shell_escape(arg):
  31         """Escapes by adding backslashes"""
  32         arg = str(arg)
  33         if UNESCAPABLE & set(arg):
  34                 return shell_quote(arg)
  35         arg = arg.replace('\\', '\\\\') # make sure this comes at the start
  36         for k, v in META_DICT.items():
  37                 arg = arg.replace(k, v)
  38         return arg