1 # Copyright (C) 2009-2010 W. Trevor King <wking@drexel.edu>
3 # This program is free software: you can redistribute it and/or modify
4 # it under the terms of the GNU General Public License as published by
5 # the Free Software Foundation, either version 3 of the License, or
6 # (at your option) any later version.
8 # This program is distributed in the hope that it will be useful,
9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 # GNU General Public License for more details.
13 # You should have received a copy of the GNU General Public License
14 # along with this program. If not, see <http://www.gnu.org/licenses/>.
16 # The author may be contacted at <wking@drexel.edu> on the Internet, or
17 # write to Trevor King, Drexel University, Physics Dept., 3141 Chestnut St.,
18 # Philadelphia PA 19104, USA.
20 """Functions for running external commands in subprocesses.
23 from subprocess import Popen, PIPE
27 _multiprocess_can_split_ = True
28 """Allow nosetests to split tests between processes.
32 class CommandError(Exception):
33 """Represent errors in command execution.
35 Instances are picklable (for passing through `multiprocessing.Queue`\s).
38 >>> a = CommandError('somefunc', 1, '', 'could not find "somefunc"')
39 >>> x = pickle.dumps(a)
40 >>> b = pickle.loads(x)
43 could not find "somefunc"
47 >>> print repr(b) # doctest: +NORMALIZE_WHITESPACE
48 CommandError(command='somefunc', status=1, stdout='',
49 stderr='could not find "somefunc"')
51 def __init__(self, command=None, status=None, stdout=None, stderr=None):
52 self.command = command
56 Exception.__init__(self, self.__str__())
58 def __getstate__(self):
61 def __setstate__(self, data):
62 self.__dict__.update(data)
66 "Command failed (%s):\n %s\n" % (self.status, self.stderr),
67 "while executing\n %s" % self.command,
72 self.__class__.__name__,
73 ', '.join(['%s=%s' % (attr, repr(getattr(self, attr)))
74 for attr in ['command', 'status', 'stdout', 'stderr']]))
77 def invoke(cmd_string, stdin=None, expect=(0,), cwd=None, verbose=False):
79 expect should be a tuple of allowed exit codes. cwd should be
80 the directory from which the command will be executed.
85 print >> sys.stderr, "%s$ %s" % (cwd, cmd_string)
87 if sys.platform != "win32" and False:
88 q = Popen(cmd_string, stdin=PIPE, stdout=PIPE, stderr=PIPE, cwd=cwd)
90 # win32 don't have os.execvp() so have to run command in a shell
91 q = Popen(cmd_string, stdin=PIPE, stdout=PIPE, stderr=PIPE,
94 raise CommandError(cmd_string, status=e.args[0], stdout="", stderr=e)
95 stdout,stderr = q.communicate(input=stdin)
98 print >> sys.stderr, "%d\n%s%s" % (status, stdout, stderr)
99 if status not in expect:
100 raise CommandError(cmd_string, status, stdout, stderr)
101 return status, stdout, stderr