Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame] | 1 | #!/usr/bin/python |
| 2 | # Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| 3 | # Use of this source code is governed by a BSD-style license that can be |
| 4 | # found in the LICENSE file. |
| 5 | |
| 6 | import os |
| 7 | import sys |
| 8 | |
| 9 | def Main(argv): |
| 10 | """This is like 'env -i', but it uses a whitelist of env variables to allow |
| 11 | through to the command being run. It attempts to strip off Xcode-added |
| 12 | values from PATH. |
| 13 | """ |
| 14 | # Note: An attempt was made to do something like: env -i bash -lc '[command]' |
| 15 | # but that fails to set the things set by login (USER, etc.), so instead |
| 16 | # the only approach that seems to work is to have a whitelist. |
| 17 | env_key_whitelist = ( |
| 18 | 'HOME', |
| 19 | 'LOGNAME', |
| 20 | # 'PATH' added below (but filtered). |
| 21 | 'PWD', |
| 22 | 'SHELL', |
| 23 | 'TEMP', |
| 24 | 'TMPDIR', |
| 25 | 'USER' |
| 26 | ) |
| 27 | |
| 28 | # Need something to run. |
| 29 | # TODO(lliabraa): Make this output a usage string and exit (here and below). |
| 30 | assert(len(argv) > 0) |
| 31 | |
| 32 | add_to_path = []; |
| 33 | first_entry = argv[0]; |
| 34 | if first_entry.startswith('ADD_TO_PATH='): |
| 35 | argv = argv[1:]; |
| 36 | add_to_path = first_entry.replace('ADD_TO_PATH=', '', 1).split(':') |
| 37 | |
| 38 | # Still need something to run. |
| 39 | assert(len(argv) > 0) |
| 40 | |
| 41 | clean_env = {} |
| 42 | |
| 43 | # Pull over the whitelisted keys. |
| 44 | for key in env_key_whitelist: |
| 45 | val = os.environ.get(key, None) |
| 46 | if not val is None: |
| 47 | clean_env[key] = val |
| 48 | |
| 49 | # Collect the developer dir as set via Xcode, defaulting it. |
| 50 | dev_prefix = os.environ.get('DEVELOPER_DIR', '/Developer/') |
| 51 | if dev_prefix[-1:] != '/': |
| 52 | dev_prefix += '/' |
| 53 | |
| 54 | # Now pull in PATH, but remove anything Xcode might have added. |
| 55 | initial_path = os.environ.get('PATH', '') |
| 56 | filtered_chunks = \ |
| 57 | [x for x in initial_path.split(':') if not x.startswith(dev_prefix)] |
| 58 | if filtered_chunks: |
| 59 | clean_env['PATH'] = ':'.join(add_to_path + filtered_chunks) |
| 60 | |
| 61 | # Add any KEY=VALUE args before the command to the cleaned environment. |
| 62 | args = argv[:] |
| 63 | while '=' in args[0]: |
| 64 | (key, val) = args[0].split('=', 1) |
| 65 | clean_env[key] = val |
| 66 | args = args[1:] |
| 67 | |
| 68 | # Still need something to run. |
| 69 | assert(len(args) > 0) |
| 70 | |
| 71 | # Off it goes... |
| 72 | os.execvpe(args[0], args, clean_env) |
| 73 | # Should never get here, so return a distinctive, non-zero status code. |
| 74 | return 66 |
| 75 | |
| 76 | if __name__ == '__main__': |
| 77 | sys.exit(Main(sys.argv[1:])) |