handy

#!/usr/bin/env python

from sys import exit, argv
from os import access, R_OK, system
from os.path import isfile

def usage():
  print 'handy v1.0'
  print 'handy [<handyfile> [<copy program> [<command number>]]]'

def check_can_read_file(filename):
  if not (isfile(filename) and access(filename, R_OK)):
    print 'Cannot read from hanyfile: ' + filename
    exit(1)

def parse_file(filename):
  output_lines = []
  commands = []
  directives = {}
  command_number = 1

  def format_title(title):
    return '\033[1;31m=== ' + title + ' ===\033[0;0m'

  def format_command(cmd, n):
    return str(n) + '. ' + cmd

  for line in open(filename).read().splitlines():
    if line.startswith('-'):
      output_lines.append(format_title(line[1:].strip()))

    if line.startswith('$'):
      cmd = line[1:].strip()
      output_lines.append(format_command(cmd, command_number))
      commands.append(cmd)
      command_number += 1

    if line.startswith('*'):
      directives[line[1:].strip()] = True

  return (output_lines, commands, directives)

def get_user_number():
  try:
    return int(raw_input('enter command number: '))
  except ValueError:
    print 'Must enter a valid number.'
    exit(1)
  except:
    print ''
    exit(0)

def escape(cmd):
  cmd = cmd.replace("'", "\\'")
  cmd = cmd.replace('"', '\\"')
  cmd = cmd.replace('%', '%%')
  return cmd

def handy(handyfile, copyprogram=None, cmdnum=None):
  check_can_read_file(handyfile)

  output_lines, commands, directives = parse_file(handyfile)

  if cmdnum is None:
      for line in output_lines:
        print line

      if directives.get('wait-for-input', False):
        cmdnum = get_user_number()
      else:
        exit(0)

  cmdnum = int(cmdnum)
  if copyprogram is not None and cmdnum > 0 and cmdnum <= len(commands):
    shell = "printf $'" + escape(commands[cmdnum - 1]) + "' | " + copyprogram
    system(shell)
  else:
    print 'Invalid command number or no copy-program specified'


if __name__ == '__main__':
  if len(argv) > 1 and len(argv) < 5:
    handy(*argv[1:])
  else:
    usage()