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 class CommandError(Exception):
28 def __init__(self, command, status, stdout, stderr):
29 strerror = ["Command failed (%d):\n %s\n" % (status, stderr),
30 "while executing\n %s" % command]
31 Exception.__init__(self, "\n".join(strerror))
32 self.command = command
37 def invoke(cmd_string, stdin=None, expect=(0,), cwd=None, verbose=False):
39 expect should be a tuple of allowed exit codes. cwd should be
40 the directory from which the command will be executed.
45 print >> sys.stderr, "%s$ %s" % (cwd, cmd_string)
47 if sys.platform != "win32" and False:
48 q = Popen(cmd_string, stdin=PIPE, stdout=PIPE, stderr=PIPE, cwd=cwd)
50 # win32 don't have os.execvp() so have to run command in a shell
51 q = Popen(cmd_string, stdin=PIPE, stdout=PIPE, stderr=PIPE,
54 raise CommandError(cmd_string, status=e.args[0], stdout="", stderr=e)
55 stdout,stderr = q.communicate(input=stdin)
58 print >> sys.stderr, "%d\n%s%s" % (status, stdout, stderr)
59 if status not in expect:
60 raise CommandError(cmd_string, status, stdout, stderr)
61 return status, stdout, stderr