import sys, os



def get_intersection(arg1, arg2):

    return set(arg1).intersection(arg2)



def cmp_file(file1, file2):

    if open(file1, "r").read() != open(file2, "r").read():

        cmd = "diff " + file1 + " " + file2 + " > " + file1 + ".dif"

        os.system(cmd)



def cmp_dir(arg1, arg2):

    files1 = os.listdir(arg1)

    files2 = os.listdir(arg2)

    files = get_intersection(files1, files2)

    for file in files:

        file1 = os.path.join(arg1, file)

        file2 = os.path.join(arg2, file)

        if os.path.isdir(file1) and os.path.isdir(file2):

            cmp_dir(file1, file2)

        else:

            cmp_file(file1, file2)



def main():

    argc = len(sys.argv)



    if argc < 2:

        sys.exit("Usage: cmpdir [srcdir] <destdir>")



    if argc == 2:

        srcdir = os.getcwd()

        dstdir = sys.argv[1]

    else:

        srcdir = sys.argv[1]

        dstdir = sys.argv[2]



    cmp_dir(srcdir, dstdir)



if __name__ == "__main__":

    main()