Source Code for Module osh.command.cat

 1  # osh 
 2  # Copyright (C) Jack Orenstein <jao@geophile.com> 
 3  # 
 4  # This program is free software; you can redistribute it and/or modify 
 5  # it under the terms of the GNU General Public License as published by 
 6  # the Free Software Foundation; either version 2 of the License, or 
 7  # (at your option) any later version. 
 8  # 
 9  # This program is distributed in the hope that it will be useful, 
10  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
11  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
12  # GNU General Public License for more details. 
13  # 
14  # You should have received a copy of the GNU General Public License 
15  # along with this program; if not, write to the Free Software 
16  # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
17   
18  r"""C{cat FILENAME} 
19   
20  Each line of the file named by C{FILENAME} is written to output. 
21  Newline characters (\n) are omitted. The C{cat} command takes no 
22  input. 
23  """ 
24   
25  import sys 
26   
27  import osh.core 
28   
29  # CLI 
30 -def _cat(): 
31      return _Cat() 
32   
33  # API 
34 -def cat(filename): 
35      r"""Each line of the file named by C{filename} is written to output. 
36      Newline characters (\n) are omitted. C{cat} takes no input. 
37      """ 
38      return _Cat().process_args(filename) 
39   
40 -class _Cat(osh.core.Generator): 
41   
42      _filename = None 
43   
44   
45      # object interface 
46   
47 -    def __init__(self): 
48          osh.core.Generator.__init__(self, '', (1, 1)) 
49   
50   
51      # OshCommand interface 
52       
53 -    def doc(self): 
54          return __doc__ 
55   
56 -    def setup(self): 
57          args = self.args() 
58          self._filename = args.next_string() 
59          if not self._filename: 
60              self.usage() 
61   
62   
63      # Generator interface 
64   
65 -    def execute(self): 
66          file = open(self._filename, 'r') 
67          try: 
68              eof = False 
69              while not eof: 
70                  line = file.readline() 
71                  if line: 
72                      if line.endswith('\n'): 
73                          line = line[:-1] 
74                      self.send(line) 
75                  else: 
76                      eof = True 
77          finally: 
78              file.close() 
79