cat.py

#!/usr/bin/env python3
# -*- coding: utf8 -*-

"""
Simple cat implementatin in Python.
"""

import sys


def cat(fobj):
    """
    Read and print content of a file object.
    """
    for line in fobj:
        print(line, end="")


def main(argv=None):
    """
    Main function.
    """
    argv = argv or sys.argv
    retcode = 0
    if len(argv) == 1:
        try:
            cat(sys.stdin)
        except KeyboardInterrupt:
            print()
            retcode = 130
        return retcode
    for filename in argv[1:]:
        try:
            with open(filename, "r") as fobj:
                cat(fobj)
        except IOError as ex:
            sys.stderr.write("%s\n" % ex)
            retcode = 1
    return retcode


if __name__ == '__main__':
    sys.exit(main())