expand-environ

#!/usr/bin/env python

import sys
import os
import optparse


class ExpandTemplateCommand(object):
    def run(self, *args):
        parser = optparse.OptionParser()
        parser.add_option("-i", "", dest="in_filename", help="input file to use (default: stdin)", metavar="FILE")
        parser.add_option("-o", "", dest="out_filename", help="output file to use (default: stdout)", metavar="FILE")
    
        (self.options, self.args) = parser.parse_args()
    
        self.in_file = sys.stdin if self.options.in_filename is None else open(self.options.in_filename, 'rb')
        self.out_file = sys.stdout if self.options.out_filename is None else open(self.options.out_filename, 'w+')
    
        data = self.in_file.read()
        self.in_file.close()
        self.out_file.write( data % os.environ )
        self.out_file.close()
    
if __name__ == '__main__':
    cmd = ExpandTemplateCommand()
    cmd.run(sys.argv)