Return the canonical path (real path) of the specified filename, eliminating any symbolic links encountered in the path.

rp.py

#!/usr/bin/env python

import os.path as filepath
import sys
from optparse import OptionParser


def main():
    parser = OptionParser(
        prog='rp', usage="%prog [path]\n\nReturn the canonical path of the specified filename\n\n  [path]\tpath of file to check\n\n  when *no args* are passed, the current working directory\n  will be set as [path].")

    options, args = parser.parse_args()
    paths = []

    if len(sys.argv) == 2 and sys.argv[1] == '-':
        for line in sys.stdin:
            paths.append(line.strip())
    else:
        for fp in sys.argv[1:]:
            paths.append(fp)

    if len(paths) > 0:
        for p in paths:
            if filepath.exists(p):
                print filepath.realpath(p)
            else:
                print p + ': No such file or directory.'
    else:
        print filepath.realpath('')

if __name__ == '__main__':
    main()