+ def canonical_cmd(self, key):
+ """Return the canonical name for a possibly-shortenned
+ command name.
+ """
+ candidates = [cmd for cmd in self.keys() if cmd.startswith(key)]
+
+ if not candidates:
+ print >> sys.stderr, 'Unknown command: %s' % key
+ print >> sys.stderr, ' Try "%s help" for a list of ' \
+ 'supported commands' % prog
+ sys.exit(1)
+ elif len(candidates) > 1:
+ print >> sys.stderr, 'Ambiguous command: %s' % key
+ print >> sys.stderr, ' Candidates are: %s' \
+ % ', '.join(candidates)
+ sys.exit(1)
+
+ return candidates[0]
+