Unix-style date script for Cygwin/Git bash

unixdate

#! /usr/bin/python

import sys
import subprocess

cmd = sys.argv[1:]

if not any(word.startswith("+") for word in cmd):
  cmd.insert(0, "+%a %b %e %H:%M:%S %Z %Y")

cmd.insert(0, "date")

exit(subprocess.Popen(cmd).wait())

This script is a companion to the GNU date on Windoze blog entry I wrote.

I've made changes to this script to recognize that other options can introduce a different format - the test was a little too naive. This is still the basic idea but a better version is in my Git repo.

Even the new changes are not perfect:

$ date -d +30\ days                    # this doesn't behave as expected, the Unix format is not specified
Thu, May  3, 2018 11:36:28 AM

$ date -d+30\ days                     # this behaves as expected, the Unix format is specified
Thu May  3 11:36:32 EDT 2018

$

When a space separated the -d option and its argument, the script incorrectly assumed that +30 days was a format specification. To solve this:

• the script could intelligently parse out every option and argument so it doesn't confuse arguments for options - not as simple as it may sound because date -ud +1\ day is valid - add one day and report UTC information. The script would have to know this is means the same as date -u -d +1\ day
• do not leave a space between the option and the argument

How dumb is it for date to have the format specified this way?