env_dump.py (1700B)
1 #!/usr/bin/env python3 2 # Copyright 2013 The Chromium Authors 3 # Use of this source code is governed by a BSD-style license that can be 4 # found in the LICENSE file. 5 6 # This script can either source a file and dump the enironment changes done by 7 # it, or just simply dump the current environment as JSON into a file. 8 9 import json 10 import optparse 11 import os 12 import shlex 13 import subprocess 14 import sys 15 16 17 def main(): 18 parser = optparse.OptionParser() 19 parser.add_option('-f', '--output-json', 20 help='File to dump the environment as JSON into.') 21 parser.add_option( 22 '-d', '--dump-mode', action='store_true', 23 help='Dump the environment to sys.stdout and exit immediately.') 24 25 parser.disable_interspersed_args() 26 options, args = parser.parse_args() 27 if options.dump_mode: 28 if args or options.output_json: 29 parser.error('Cannot specify args or --output-json with --dump-mode.') 30 json.dump(dict(os.environ), sys.stdout) 31 else: 32 if not options.output_json: 33 parser.error('Requires --output-json option.') 34 35 envsetup_cmd = ' '.join(map(shlex.quote, args)) 36 full_cmd = [ 37 'bash', '-c', 38 '. %s > /dev/null; %s -d' % (envsetup_cmd, os.path.abspath(__file__)) 39 ] 40 try: 41 output = subprocess.check_output(full_cmd) 42 except Exception as e: 43 sys.exit('Error running %s and dumping environment.' % envsetup_cmd) 44 45 env_diff = {} 46 new_env = json.loads(output) 47 for k, val in new_env.items(): 48 if k == '_' or (k in os.environ and os.environ[k] == val): 49 continue 50 env_diff[k] = val 51 with open(options.output_json, 'w') as f: 52 json.dump(env_diff, f) 53 54 55 if __name__ == '__main__': 56 sys.exit(main())