Readline

Inspired by Doug Hellman’s great article I played with readline a bit. I will use cmd for my purposes, but here’s the code for future reference:

stuff = ['foo/bar', 'foo/baz', 'qux']

import logging
LOG_FILENAME = '/tmp/completer.log'
logging.basicConfig(filename=LOG_FILENAME,
                    level=logging.DEBUG,
                    )

class SimpleCompleter(object):

    def __init__(self, options):
        self.options = sorted(options)
        return

    def complete(self, text, state):
        response = None
        logging.debug('STATE: %s', state)
        origline = readline.get_line_buffer()
        begin = readline.get_begidx()
        end = readline.get_endidx()
        being_completed = origline[begin:end]
        logging.debug('origline=%s', repr(origline))
        logging.debug('begin=%s', begin)
        logging.debug('end=%s', end)
        logging.debug('being_completed=%s', being_completed)
        if state == 0:


            if end == 0:
                self.matches = self.options
            else:
                self.matches = [
                        s[begin:] # only the remaining characters
                        for s in self.options
                        if s.startswith(origline) # should begin with complete line input
                        ]
                # bash-like: if remaining string was found, append a space, ending completion
                if len(self.matches) == 1:
                    response = self.matches[state] + ' '
                    return response
                logging.debug('options starting with %s: %s', origline, repr(self.matches))

        try:
            response = self.matches[state]
        except IndexError:
            response = None
        return response

readline.set_completer(SimpleCompleter(stuff).complete)
readline.parse_and_bind('tab: complete')

thing = raw_input('> ')

print 'result: ', thing