python写的很简单的cat功能程序

import os,sys

def readfile(filename):
    '''Print a file to the standard output.'''
    print '==================%s : %s==================' % (filename, os.path.abspath(filename))
    fd = file(filename)
    
    while True:
        try:
            text = fd.next()
        except:
            break
        print text, # comma is for ignoring '\n'
# while True:
# line = fd.readline()
# if len(line) == 0:
# break
# print line, # notice comma
    fd.close()

if __name__ == "__main__":
# os.chdir(os.path.expanduser("~"))
    if len(sys.argv) < 2:
        print 'please use command: '
        sys.exit()
# for argvs in sys.argv[:]:
# print argvs
    if sys.argv[1].startswith('--'):
        option = sys.argv[1][2:]
        if option == 'version':
            print 'Version 1.0'
        elif option == 'help':
            print '''
Options include:
    --version : Display version number
    --help : Display help
    python wpr.py filename : parse the file'''
        else:
            print 'Unknown option.'
            sys.exit()
    else:
        for filename in sys.argv[1:]:
            readfile(filename)
# print os.getcwd()


luther@gliethttp:~/python$ python wpr.py luther.txt
==================luther.txt : /home/luther/python/luther.txt==================
luther.gliethttp 2008年12月16日11点6分