OS X Command Line Password Generator

genpass.py

#!/usr/bin/env python

import sys
import os
import string
import random

DICT_FILE = '/usr/share/dict/words'
DEFAULT_LENGTH = 24

# CHARACTER_SET = string.letters + string.letters + string.letters + string.punctuation
# CHARACTER_SET = string.letters + string.letters + string.digits
CHARACTER_SET = string.lowercase + string.digits

def passgen(size=DEFAULT_LENGTH, chars=CHARACTER_SET):
    return ''.join(random.choice(chars) for _ in range(size))

def shescape(s):
   return s.replace("'", "'\\''").replace('"', '\"')

def passgen_words(length=4):
    if not os.path.isfile(DICT_FILE):
        sys.stderr.write("Dict file {} not found".format(DICT_FILE))
        sys.exit(1)
    return ' '.join(random_line(DICT_FILE) for _ in range(length))

def random_line(file_path):
    fp = open(file_path, 'r')
    line = next(fp)
    for num, aline in enumerate(fp):
      if random.randrange(num + 2): continue
      line = aline.strip('\n').lower()
    return line

def clipboard_copy(passwd_string):
    cmd = 'echo \'%s\' | tr -d "\n" | tr -d "\n" | pbcopy' % shescape(passwd_string)
    os.system(cmd)

def run(args):
    size = 12
    if len(sys.argv) > 1:
        arg = sys.argv[1]
        if arg == 'w' or arg == 'word' or arg == 'words':
            generated_pass = passgen_words(4)
        else:
            size = int(arg)
            generated_pass = passgen(size)
    else:
        generated_pass = passgen()
    print generated_pass
    clipboard_copy(generated_pass)

if __name__ == '__main__':
    sys.exit(run(sys.argv))