使用python模拟命令行终端的示例

可以对？显示帮助信息，需要立即获取输入的字符，因此需要用到termios模块

另外需要对tab键做处理，当按下tab键时可以进行自动补全

#! /usr/bin/env python
# coding=utf-8

import os
import sys
import tty
import termios

'''
Enter: 13
Back:  127
?:   63
C-h:  8
C-w:  23
Tab:  9
C-u:  21
C-c:  3
C-d:  4
C-\:  28
SPACE: 32
'''

CLI_KEY_CNCR = 13
CLI_KEY_BACK = 127
CLI_KEY_QMARK = 63
CLI_KEY_CTRLH = 8
CLI_KEY_CTRLW = 23
CLI_KEY_TAB  = 9
CLI_KEY_CTRLU = 21
CLI_KEY_CTRLC = 3
CLI_KEY_CTRLD = 4
CLI_KEY_QUIT = 28
CLI_KEY_SPACE = 32
CLI_KEY_TABLEN = 4

class CLI(object):
  def __init__(self):
    self.line = ''
    self.line_complete = ''
    self.completer_on = False
    self.completer_dict = {}
    self.completer_dict_keys = self.completer_dict.keys()
    self.completer_id = 0
    self.completer_cnt = len(self.completer_dict)
  def getch(self):
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    try:
      tty.setraw(fd)
      ch = sys.stdin.read(1)
    finally:
      termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    return ch
  def completer_kw_update(self):
    self.completer_dict_keys = self.completer_dict.keys()
    self.completer_dict_keys.sort()
    self.completer_cnt = len(self.completer_dict)
  def completer_kw_add(self, key, word):
    self.completer_dict[key] = word
    self.completer_kw_update()
  def completer_kw_clear(self):
    self.completer_dict.clear()
    self.completer_id_update()
  def completer_id_update(self):
    self.completer_kw_update()
    if self.completer_id < self.completer_cnt - 1:
      self.completer_id += 1
    else:
      self.completer_id = 0
  def completer_wd_select(self, word):
    if not word:
      return ''
    cnt = self.completer_cnt
    while cnt>0:
      completer = self.completer_dict_keys[self.completer_id]
      self.completer_id_update()
      cnt -= 1
      if word == completer[:len(word)]:
        return completer[len(word):]
    return ''
  def printf(self, info=''):
    sys.stdout.write(info)
  def show_spec_len_str(self, info, maxlen, spacech=' '):
    'display a string of the specified length'
    maxlen = maxlen
    infolen = len(info)
    if maxlen < infolen:
      maxlen = infolen
    while infolen>0:
      ch = info[-infolen]
      for i in range(self.char_memory_len(ch)):
        self.printf(info[i-infolen])
      infolen -= self.char_memory_len(ch)
      maxlen -= self.char_display_len(ch)
    while maxlen>0:
      self.printf(spacech)
      maxlen -= self.char_display_len(spacech)
  def show_help_info(self):
    if self.completer_on:
      line = self.line_complete
    else:
      line = self.line
    lastwd = ''
    show_all = False
    if not line or line[-1] == ' ':
      show_all = True
    else:
      lastwd = line.split()[-1]
    if self.completer_dict:
      maxlen = max([len(info) for info in self.completer_dict])
    else:
      maxlen = 12
    for info in self.completer_dict:
      if show_all or lastwd == info[:len(lastwd)]:
        self.printf(' ')
        self.show_spec_len_str(info, maxlen)
        self.printf(' ')
        self.printf(self.completer_dict[info])
        self.printf('\r\n')
  def is_chinese_char(self, ch):
    return ord(ch) > 127
  def char_display_len(self, ch):
    if self.is_chinese_char(ch):
      return 2
    elif ord(ch) == CLI_KEY_TAB:
      return CLI_KEY_TABLEN
    else:
      return 1
  def char_memory_len(self, ch):
    if self.is_chinese_char(ch):
      return 3
    else:
      return 1
  def rm_last_char(self, line):
    lastch = ''
    rmlen = 0
    if len(line)>0:
      lastch = line[-1]
      self.printf('\b \b' * self.char_display_len(lastch))
      rmlen = self.char_memory_len(lastch)
      if len(line) >= rmlen:
        line = line[:-(rmlen)]
      else:
        rmlen = len(line)
        line = ''
    return rmlen, line
  def rm_last_word(self, line):
    lastwd = ''
    linelen = len(line)
    rspacelen = linelen - len(line.rstrip())
    if not linelen:
      return line
    lastwd = line.split()[-1]
    backlen = len(lastwd) + rspacelen
    rmlen = 0
    while backlen>0 and line:
      rmlen, line = self.rm_last_char(line)
      backlen -= rmlen
    return line
  def rm_one_line(self, line):
    rmlen = 0
    while line:
      rmlen, line = self.rm_last_char(line)
    return line
  def do_line_complete_proc(self):
    line = self.line
    line_complete = self.line_complete
    lastwd = ''
    self.printf('\r\n')
    if self.line_complete:
      self.printf(self.line_complete)
    else:
      self.printf(self.line)
    if not line:
      return line
    lastwd = line.split()[-1]
    completer = self.completer_wd_select(lastwd)
    if not completer.strip():
      self.line_complete = line
      return line
    backlen = len(line_complete) - len(line)
    while backlen>0 and line_complete:
      rmlen, line_complete = self.rm_last_char(line_complete)
      backlen -= rmlen
    self.printf(completer)
    line_complete = line + completer
    self.line_complete = line_complete
  def do_line_complete_end(self):
    if self.completer_on:
      self.line = self.line_complete
      self.line_complete = ''
      self.completer_on = False
  def get_line(self):
    self.line = ''
    self.line_complete = ''
    self.completer_on = False
    while True:
      ch = self.getch()
      if ch == '\r' or ch == '\n':
        self.do_line_complete_end()
        self.printf('\r\n')
        break
      elif ord(ch) == CLI_KEY_BACK or ord(ch) == CLI_KEY_CTRLH:
        if self.completer_on:
          rmlen, self.line_complete = self.rm_last_char(self.line_complete)
        else:
          rmlen, self.line = self.rm_last_char(self.line)
        self.do_line_complete_end()
      elif ord(ch) == CLI_KEY_QMARK:
        self.printf('?')
        self.printf('\r\n')
        self.show_help_info()
        if self.completer_on:
          self.printf(self.line_complete)
        else:
          self.printf(self.line)
      elif ord(ch) == CLI_KEY_CTRLW:
        if self.completer_on:
          self.line_complete = self.rm_last_word(self.line_complete)
        else:
          self.line = self.rm_last_word(self.line)
        self.do_line_complete_end()
      elif ord(ch) == CLI_KEY_TAB:
        self.completer_on = True
        self.do_line_complete_proc()
      elif ord(ch) == CLI_KEY_CTRLD:
        if self.line:
          return self.line
        else:
          return ch
      elif ord(ch) == CLI_KEY_QUIT:
        self.printf('\r\n Interrupted by <Ctrl-\>.\r\n')
        sys.exit()
      elif ord(ch) == CLI_KEY_CTRLU:
        if self.completer_on:
          self.line_complete = self.rm_one_line(self.line_complete)
        else:
          self.line = self.rm_one_line(self.line)
        self.do_line_complete_end()
      elif ord(ch) == CLI_KEY_SPACE:
        self.printf(ch)
        if self.completer_on:
          self.line_complete += ch
        else:
          self.line += ch
      else:
        self.printf(ch)
        self.do_line_complete_end()
        self.line += ch
        # chinese qmask proc
        if ord(ch) == 159 and len(self.line)>= 3 and self.line[-3:] == '\xef\xbc\x9f':
          self.printf('\r\n')
          self.line = self.line[:-3]
          self.show_help_info()
          self.printf(self.line)
    return self.line
  def get_raw_line(self):
    self.raw_line = ''
    while True:
      ch = self.getch()
      if ch == '\r' or ch == '\n':
        self.printf('\r\n')
        break
      elif ord(ch) == CLI_KEY_BACK or ord(ch) == CLI_KEY_CTRLH:
        rmlen, self.raw_line = self.rm_last_char(self.raw_line)
      elif ord(ch) == CLI_KEY_CTRLW:
        self.raw_line = self.rm_last_word(self.raw_line)
      elif ord(ch) == CLI_KEY_TAB:
        self.printf(' ' * self.char_display_len(ch))
        self.raw_line += ch
      elif ord(ch) == CLI_KEY_CTRLD:
        if self.raw_line:
          return self.raw_line
        else:
          return ch
      elif ord(ch) == CLI_KEY_QUIT:
        self.printf('\r\n Interrupted by <Ctrl-\>.\r\n')
        sys.exit()
      elif ord(ch) == CLI_KEY_CTRLU:
        self.raw_line = self.rm_one_line(self.raw_line)
      else:
        self.raw_line += ch
        self.printf(ch)
    return self.raw_line

def test():
  cli = CLI()
  help_info = {
  	'hello0':   'say hello 0',
  	'hello1':   'say hello 1',
  	'hellohello': 'say hello hello',
  	'hellohehe': 'say hello hehe',
  	'hellohi':  'say hello hi',
  	'你好啊':   'say 你好啊',
  	'你好吗':   'say 你好吗',
  	'你好哈':   'say 你好哈',
  	}
  for key in help_info:
    cli.completer_kw_add(key, help_info[key])
  while True:
    line = cli.get_line()
    if len(line) == 1 and ord(line[0]) == CLI_KEY_CTRLD:
      break
    if line == 'quit':
      break
    print(line)

if __name__ == "__main__":
  test()

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