addr2name

#! /usr/bin/env python


from socket import gethostbyaddr
from sys import argv


DELIM = ","


def main():
    if len(argv) != 3:
        print "Usage: %s infile outfile" % argv[0]
        return
    with open(argv[1], "r") as fin, open(argv[2], "w") as fout:
        for line in fin:
            chunk = line.strip().split(DELIM)
            string = "{user}@{host},{pwd}\n".format(user=chunk[1], pwd=chunk[2], host=gethostbyaddr(chunk[0])[0])
            fout.write(string)


if __name__ == "__main__":
    main()