#!/usr/bin/python
#
# $Id$
# $HeadURL$
#
# Remove duplicate entries from a path as well as
# user supplied entries.
#
# Usage:
#
#   filter_path PATHVAR [p1 p2 p3 ...]
#
#  The PATHVAR should be the name of an environment
# variable like "PATH" (not "$PATH"). This will remove
# duplicate entries or any entries specified by the
# user. Order of the path is preserved. If a duplicate 
# is removed, it is always the one(s) occurring later.
# Empty entries are also removed.
#
# This will not print a newline at the end of the new
# path. This is to make it easy to set environment
# variables in scripts to the output of this.
#

import sys
import os

if (len(sys.argv)>1):
	varname = sys.argv[1]
	var = os.environ.get(varname)

	filter_paths = sys.argv[2:]

	newpaths = []
	if (var != 'none' ):
		paths = var.split(':')
		for path in paths:
			if len(path)>0 : # remove empty entries
				if path not in newpaths: # remove duplicates
					if path not in filter_paths: # remove user supplied paths
						newpaths.append(path)
		if len(newpaths)>0:
			newpath = newpaths[0]
			for path in newpaths[1:]: newpath = '%s:%s' % (newpath,path)
			sys.stdout.write(newpath)

	else:
		#exit -1
		pass