From 54df6c66ccebfa238126bad543b1af08524cedc6 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Tue, 8 Oct 2013 15:58:58 -0400
Subject: [PATCH] chpathtool: clean up arg parsing to use proper argparse
 module

Also throw in some documentation for good measure since not everyone knows
what this thing does.
---
 bin/chpathtool.py | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/bin/chpathtool.py b/bin/chpathtool.py
index b8c6fd5cb..aa3b7d478 100755
--- a/bin/chpathtool.py
+++ b/bin/chpathtool.py
@@ -2,6 +2,10 @@
 # Copyright 2011-2013 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
+"""Helper tool for converting installed files to custom prefixes.
+
+In other words, eprefixy $D for Gentoo/Prefix."""
+
 import io
 import os
 import stat
@@ -142,14 +146,16 @@ def chpath_inplace_symlink(filename, st, old, new):
 
 def main(argv):
 
-	usage = '%(prog)s [options] <location> <old> <new>'
-	parser = ArgumentParser(usage=usage)
-	options, args = parser.parse_known_args(argv)
-
-	if len(args) != 3:
-		parser.error('3 args required, got %s' % (len(args),))
+	parser = ArgumentParser(description=__doc__)
+	parser.add_argument('location', default=None,
+		help='root directory (e.g. $D)')
+	parser.add_argument('old', default=None,
+		help='original build prefix (e.g. /)')
+	parser.add_argument('new', default=None,
+		help='new install prefix (e.g. $EPREFIX)')
+	opts = parser.parse_args(argv)
 
-	location, old, new = args
+	location, old, new = opts.location, opts.old, opts.new
 
 	is_text_file = IsTextFile()
 
-- 
2.26.2