1#!/usr/bin/env python3 2 3import re 4import sys 5import subprocess 6 7flex = sys.argv[1] 8 9out = subprocess.check_output([flex, '--version'], universal_newlines=True, 10 stderr=subprocess.STDOUT, stdin=subprocess.DEVNULL) 11print(re.search(r'(\d+\.\d+(\.\d+)?)', out).group()) 12