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Text File  |  1994-08-01  |  2KB  |  92 lines
  1. # A generic class to build line-oriented command interpreters
  2.  
  3. import string
  4. import sys
  5. import linecache
  6.  
  7. PROMPT = '(Cmd) '
  8. IDENTCHARS = string.letters + string.digits + '_'
  9.  
  10. class Cmd:
  11.  
  12.     def __init__(self):
  13.         self.prompt = PROMPT
  14.         self.identchars = IDENTCHARS
  15.         self.lastcmd = ''
  16.  
  17.     def cmdloop(self):
  18.         stop = None
  19.         while not stop:
  20.             try:
  21.                 line = raw_input(self.prompt)
  22.             except EOFError:
  23.                 line = 'EOF'
  24.             stop = self.onecmd(line)
  25.  
  26.     def onecmd(self, line):
  27.         line = string.strip(line)
  28.         if not line:
  29.             line = self.lastcmd
  30.         else:
  31.             self.lastcmd = line
  32.         i, n = 0, len(line)
  33.         while i < n and line[i] in self.identchars: i = i+1
  34.         cmd, arg = line[:i], string.strip(line[i:])
  35.         if cmd == '':
  36.             return self.default(line)
  37.         else:
  38.             try:
  39.                 func = getattr(self, 'do_' + cmd)
  40.             except AttributeError:
  41.                 return self.default(line)
  42.             return func(arg)
  43.  
  44.     def default(self, line):
  45.         print '*** Unknown syntax:', line
  46.  
  47.     def do_help(self, arg):
  48.         if arg:
  49.             # XXX check arg syntax
  50.             try:
  51.                 func = getattr(self, 'help_' + arg)
  52.             except:
  53.                 print '*** No help on', `arg`
  54.                 return
  55.             func()
  56.         else:
  57.             import newdir
  58.             names = newdir.dir(self.__class__)
  59.             cmds_doc = []
  60.             cmds_undoc = []
  61.             help = {}
  62.             for name in names:
  63.                 if name[:5] == 'help_':
  64.                     help[name[5:]]=1
  65.             for name in names:
  66.                 if name[:3] == 'do_':
  67.                     cmd=name[3:]
  68.                     if help.has_key(cmd):
  69.                         cmds_doc.append(cmd)
  70.                         del help[cmd]
  71.                     else:
  72.                         cmds_undoc.append(cmd)
  73.             print 
  74.             self.print_topics("Documented commands (type help " \
  75.                                   "<topic>):",cmds_doc, 15, 80)
  76.             self.print_topics("Miscellaneous help topics:",
  77.                                   help.keys(), 15, 80)
  78.             self.print_topics("Undocumented commands:", 
  79.                                   cmds_undoc, 15, 80)
  80.  
  81.     def print_topics(self, header, cmds, cmdlen, maxcol):
  82.         if cmds:
  83.             print header;
  84.             print "="*len(header)
  85.             (cmds_per_line,junk)=divmod(maxcol,cmdlen)
  86.             col=cmds_per_line
  87.             for cmd in cmds:
  88.                 if col==0: print
  89.                 print (("%-"+`cmdlen`+"s") % cmd),
  90.                 col = (col+1) % cmds_per_line
  91.             print "\n"
  92.