readline — GNU readline 库

配置

# readline_parse_and_bind.py
try:
    import gnureadline as readline
except ImportError:
    import readline

readline.parse_and_bind('tab: complete')
readline.parse_and_bind('set editing-mode vi')

while True:
    line = input('Prompt ("stop" to quit): ')
    if line == 'stop':
        break
    print('ENTERED: {!r}'.format(line))

# myreadline.rc
# Turn on tab completion
tab: complete

# Use vi editing mode instead of emacs
set editing-mode vi

# readline_read_init_file.py
try:
    import gnureadline as readline
except ImportError:
    import readline

readline.read_init_file('myreadline.rc')

while True:
    line = input('Prompt ("stop" to quit): ')
    if line == 'stop':
        break
    print('ENTERED: {!r}'.format(line))

Completing Text

# readline_completer.py
try:
    import gnureadline as readline
except ImportError:
    import readline
import logging

LOG_FILENAME = '/tmp/completer.log'
logging.basicConfig(
    format='%(message)s',
    filename=LOG_FILENAME,
    level=logging.DEBUG,
)


class SimpleCompleter:

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

    def complete(self, text, state):
        response = None
        if state == 0:
            # This is the first time for this text,
            # so build a match list.
            if text:
                self.matches = [
                    s
                    for s in self.options
                    if s and s.startswith(text)
                ]
                logging.debug('%s matches: %s',
                              repr(text), self.matches)
            else:
                self.matches = self.options[:]
                logging.debug('(empty input) matches: %s',
                              self.matches)

        # Return the state'th item from the match list,
        # if we have that many.
        try:
            response = self.matches[state]
        except IndexError:
            response = None
        logging.debug('complete(%s, %s) => %s',
                      repr(text), state, repr(response))
        return response


def input_loop():
    line = ''
    while line != 'stop':
        line = input('Prompt ("stop" to quit): ')
        print('Dispatch {}'.format(line))


# Register the completer function
OPTIONS = ['start', 'stop', 'list', 'print']
readline.set_completer(SimpleCompleter(OPTIONS).complete)

# Use the tab key for completion
readline.parse_and_bind('tab: complete')

# Prompt the user for text
input_loop()

Accessing the Completion Buffer

# readline_buffer.py
try:
    import gnureadline as readline
except ImportError:
    import readline
import logging

LOG_FILENAME = '/tmp/completer.log'
logging.basicConfig(
    format='%(message)s',
    filename=LOG_FILENAME,
    level=logging.DEBUG,
)


class BufferAwareCompleter:

    def __init__(self, options):
        self.options = options
        self.current_candidates = []

    def complete(self, text, state):
        response = None
        if state == 0:
            # This is the first time for this text,
            # so build a match list.

            origline = readline.get_line_buffer()
            begin = readline.get_begidx()
            end = readline.get_endidx()
            being_completed = origline[begin:end]
            words = origline.split()

            logging.debug('origline=%s', repr(origline))
            logging.debug('begin=%s', begin)
            logging.debug('end=%s', end)
            logging.debug('being_completed=%s', being_completed)
            logging.debug('words=%s', words)

            if not words:
                self.current_candidates = sorted(
                    self.options.keys()
                )
            else:
                try:
                    if begin == 0:
                        # first word
                        candidates = self.options.keys()
                    else:
                        # later word
                        first = words[0]
                        candidates = self.options[first]

                    if being_completed:
                        # match options with portion of input
                        # being completed
                        self.current_candidates = [
                            w for w in candidates
                            if w.startswith(being_completed)
                        ]
                    else:
                        # matching empty string,
                        # use all candidates
                        self.current_candidates = candidates

                    logging.debug('candidates=%s',
                                  self.current_candidates)

                except (KeyError, IndexError) as err:
                    logging.error('completion error: %s', err)
                    self.current_candidates = []

        try:
            response = self.current_candidates[state]
        except IndexError:
            response = None
        logging.debug('complete(%s, %s) => %s',
                      repr(text), state, response)
        return response


def input_loop():
    line = ''
    while line != 'stop':
        line = input('Prompt ("stop" to quit): ')
        print('Dispatch {}'.format(line))


# Register our completer function
completer = BufferAwareCompleter({
    'list': ['files', 'directories'],
    'print': ['byname', 'bysize'],
    'stop': [],
})
readline.set_completer(completer.complete)

# Use the tab key for completion
readline.parse_and_bind('tab: complete')

# Prompt the user for text
input_loop()

输入历史

# readline_history.py
try:
    import gnureadline as readline
except ImportError:
    import readline
import logging
import os

LOG_FILENAME = '/tmp/completer.log'
HISTORY_FILENAME = '/tmp/completer.hist'

logging.basicConfig(
    format='%(message)s',
    filename=LOG_FILENAME,
    level=logging.DEBUG,
)


def get_history_items():
    num_items = readline.get_current_history_length() + 1
    return [
        readline.get_history_item(i)
        for i in range(1, num_items)
    ]


class HistoryCompleter:

    def __init__(self):
        self.matches = []

    def complete(self, text, state):
        response = None
        if state == 0:
            history_values = get_history_items()
            logging.debug('history: %s', history_values)
            if text:
                self.matches = sorted(
                    h
                    for h in history_values
                    if h and h.startswith(text)
                )
            else:
                self.matches = []
            logging.debug('matches: %s', self.matches)
        try:
            response = self.matches[state]
        except IndexError:
            response = None
        logging.debug('complete(%s, %s) => %s',
                      repr(text), state, repr(response))
        return response


def input_loop():
    if os.path.exists(HISTORY_FILENAME):
        readline.read_history_file(HISTORY_FILENAME)
    print('Max history file length:',
          readline.get_history_length())
    print('Startup history:', get_history_items())
    try:
        while True:
            line = input('Prompt ("stop" to quit): ')
            if line == 'stop':
                break
            if line:
                print('Adding {!r} to the history'.format(line))
    finally:
        print('Final history:', get_history_items())
        readline.write_history_file(HISTORY_FILENAME)


# Register our completer function
readline.set_completer(HistoryCompleter().complete)

# Use the tab key for completion
readline.parse_and_bind('tab: complete')

# Prompt the user for text
input_loop()

Hooks 钩子

# readline_hooks.py
try:
    import gnureadline as readline
except ImportError:
    import readline


def startup_hook():
    readline.insert_text('from startup_hook')


def pre_input_hook():
    readline.insert_text(' from pre_input_hook')
    readline.redisplay()


readline.set_startup_hook(startup_hook)
readline.set_pre_input_hook(pre_input_hook)
readline.parse_and_bind('tab: complete')

while True:
    line = input('Prompt ("stop" to quit): ')
    if line == 'stop':
        break
    print('ENTERED: {!r}'.format(line))