#!/usr/bin/env python
#
# Read a whitespace-separated list of version numbers on stdin
# and output the latest version.
#
# A version number is a list of numbers separated by dots, followed
# by an optional alphanumeric string (there may or may not be a dot
# before this string). The numbers must not have leading zeros.
# Typical examples: "5.4.3a" or "1.10.rc0"
#
# Any word in the input which does not start with a digit, is ignored.
# Any word which does start with a digit, but is not of the required
# form, is an error. Trailing alphanumeric strings are chopped off and
# ignored; they don't appear in the output.
#
# AUTHOR: Jeroen Demeyer (2012-10-01)
#
# Make this script compatible with Python 3.
from __future__ import print_function
def version_to_tuple(v):
"""
Convert a version number like "5.4.3a" to a tuple (5,4,3).
"""
n = "" # Current number as string
t = [] # List of numbers
for c in v:
if c.isdigit():
n += c
elif c == ".":
if len(n) == 0:
raise ValueError("Empty number in version string '{}'".format(v))
if n[0] == '0' and len(n) >= 2:
raise ValueError("Leading zeros not allowed in version string '{}'".format(v))
t.append(int(n))
n = ""
elif c.isalpha():
break
else:
raise ValueError("Illegal character '{}' in version string '{}'".format(c,v))
if len(n) > 0:
t.append(int(n))
return tuple(t)
def tuple_to_version(t):
"""
Convert a tuple like (5,4,3) to a version number "5.4.3"
"""
return str.join(".", [str(x) for x in t])
import sys
L = sys.stdin.read().split()
debug = ' '.join(L)
L = [version_to_tuple(s) for s in L if len(s) > 0 and s[0].isdigit()]
if len(L) == 0:
sys.exit(0)
L = sorted(L, reverse=True)
ver = tuple_to_version(L[0])
debug = debug + ' => ' + ver
print(ver)
print(debug, file=sys.stderr)
