bin/Command.py

   1 #!/usr/bin/env python
   2 #
   3 # XXX Python script template
   4 #
   5 # XXX Describe what the script does here.
   6 #
   7
   8 import getopt
   9 import os
  10 import shlex
  11 import sys
  12
  13 class Usage(Exception):
  14     def __init__(self, msg):
  15         self.msg = msg
  16
  17 class CommandRunner:
  18     """
  19     Representation of a command to be executed.
  20     """
  21
  22     def __init__(self, dictionary={}):
  23         self.subst_dictionary(dictionary)
  24
  25     def subst_dictionary(self, dictionary):
  26         self._subst_dictionary = dictionary
  27
  28     def subst(self, string, dictionary=None):
  29         """
  30         Substitutes (via the format operator) the values in the specified
  31         dictionary into the specified command.
  32
  33         The command can be an (action, string) tuple.  In all cases, we
  34         perform substitution on strings and don't worry if something isn't
  35         a string.  (It's probably a Python function to be executed.)
  36         """
  37         if dictionary is None:
  38             dictionary = self._subst_dictionary
  39         if dictionary:
  40             try:
  41                 string = string % dictionary
  42             except TypeError:
  43                 pass
  44         return string
  45
  46     def do_display(self, string):
  47         if type(string) == type(()):
  48             func = string[0]
  49             args = string[1:]
  50             s = '%s(%s)' % (func.__name__, ', '.join(map(repr, args)))
  51         else:
  52             s = self.subst(string)
  53         if not s.endswith('\n'):
  54             s += '\n'
  55         sys.stdout.write(s)
  56         sys.stdout.flush()
  57
  58     def do_not_display(self, string):
  59         pass
  60
  61     def do_execute(self, command):
  62         if type(command) == type(''):
  63             command = self.subst(command)
  64             cmdargs = shlex.split(command)
  65             if cmdargs[0] == 'cd':
  66                  command = (os.chdir,) + tuple(cmdargs[1:])
  67             elif cmdargs[0] == 'mkdir':
  68                  command = (os.mkdir,) + tuple(cmdargs[1:])
  69         if type(command) == type(()):
  70             func = command[0]
  71             args = command[1:]
  72             return func(*args)
  73         else:
  74             return os.system(command)
  75
  76     def do_not_execute(self, command):
  77         pass
  78
  79     display = do_display
  80     execute = do_execute
  81
  82     def run(self, command, display=None):
  83         """
  84         Runs this command, displaying it first.
  85
  86         The actual display() and execute() methods we call may be
  87         overridden if we're printing but not executing, or vice versa.
  88         """
  89         if display is None:
  90             display = command
  91         self.display(display)
  92         return self.execute(command)
  93
  94 def main(argv=None):
  95     if argv is None:
  96         argv = sys.argv
  97
  98     short_options = 'hnq'
  99     long_options = ['help', 'no-exec', 'quiet']
 100
 101     helpstr = """\
 102 Usage:  script-template.py [-hnq]
 103
 104   -h, --help                    Print this help and exit
 105   -n, --no-exec                 No execute, just print command lines
 106   -q, --quiet                   Quiet, don't print command lines
 107 """
 108
 109     try:
 110         try:
 111             opts, args = getopt.getopt(argv[1:], short_options, long_options)
 112         except getopt.error, msg:
 113             raise Usage(msg)
 114
 115         for o, a in opts:
 116             if o in ('-h', '--help'):
 117                 print helpstr
 118                 sys.exit(0)
 119             elif o in ('-n', '--no-exec'):
 120                 Command.execute = Command.do_not_execute
 121             elif o in ('-q', '--quiet'):
 122                 Command.display = Command.do_not_display
 123     except Usage, err:
 124         sys.stderr.write(err.msg)
 125         sys.stderr.write('use -h to get help')
 126         return 2
 127
 128     commands = [
 129     ]
 130
 131     for command in [ Command(c) for c in commands ]:
 132         status = command.run(command)
 133         if status:
 134             sys.exit(status)
 135
 136 if __name__ == "__main__":
 137     sys.exit(main())
 138
 139 # Local Variables:
 140 # tab-width:4
 141 # indent-tabs-mode:nil
 142 # End:
 143 # vim: set expandtab tabstop=4 shiftwidth=4: