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Greg Wardb4dbfb31999-08-14 23:57:17 +00001"""distutils.spawn
2
3Provides the 'spawn()' function, a front-end to various platform-
Greg Ward88608ca2000-08-02 01:08:02 +00004specific functions for launching another program in a sub-process.
5Also provides the 'find_executable()' to search the path for a given
Greg Warda30f7ac2000-09-26 02:00:51 +00006executable name.
7"""
Greg Wardb4dbfb31999-08-14 23:57:17 +00008
9# created 1999/07/24, Greg Ward
10
Greg Ward3ce77fd2000-03-02 01:49:45 +000011__revision__ = "$Id$"
Greg Wardb4dbfb31999-08-14 23:57:17 +000012
13import sys, os, string
14from distutils.errors import *
15
16
17def spawn (cmd,
18 search_path=1,
19 verbose=0,
20 dry_run=0):
21
22 """Run another program, specified as a command list 'cmd', in a new
Greg Warda30f7ac2000-09-26 02:00:51 +000023 process. 'cmd' is just the argument list for the new process, ie.
24 cmd[0] is the program to run and cmd[1:] are the rest of its arguments.
25 There is no way to run a program with a name different from that of its
26 executable.
Greg Wardb4dbfb31999-08-14 23:57:17 +000027
Greg Warda30f7ac2000-09-26 02:00:51 +000028 If 'search_path' is true (the default), the system's executable search
29 path will be used to find the program; otherwise, cmd[0] must be the
30 exact path to the executable. If 'verbose' is true, a one-line summary
31 of the command will be printed before it is run. If 'dry_run' is true,
32 the command will not actually be run.
Greg Wardb4dbfb31999-08-14 23:57:17 +000033
Greg Warda30f7ac2000-09-26 02:00:51 +000034 Raise DistutilsExecError if running the program fails in any way; just
35 return on success.
36 """
Greg Wardb4dbfb31999-08-14 23:57:17 +000037 if os.name == 'posix':
Greg Warda30f7ac2000-09-26 02:00:51 +000038 _spawn_posix(cmd, search_path, verbose, dry_run)
Greg Warda4d132a1999-09-08 02:23:28 +000039 elif os.name == 'nt':
Greg Warda30f7ac2000-09-26 02:00:51 +000040 _spawn_nt(cmd, search_path, verbose, dry_run)
Greg Wardb4dbfb31999-08-14 23:57:17 +000041 else:
42 raise DistutilsPlatformError, \
43 "don't know how to spawn programs on platform '%s'" % os.name
44
45# spawn ()
46
Greg Warda4d132a1999-09-08 02:23:28 +000047
Greg Warde2b44522000-03-07 03:25:20 +000048def _nt_quote_args (args):
Greg Warda30f7ac2000-09-26 02:00:51 +000049 """Quote command-line arguments for DOS/Windows conventions: just
50 wraps every argument which contains blanks in double quotes, and
51 returns a new argument list.
52 """
Greg Warde2b44522000-03-07 03:25:20 +000053
54 # XXX this doesn't seem very robust to me -- but if the Windows guys
55 # say it'll work, I guess I'll have to accept it. (What if an arg
56 # contains quotes? What other magic characters, other than spaces,
57 # have to be escaped? Is there an escaping mechanism other than
58 # quoting?)
59
Greg Warda30f7ac2000-09-26 02:00:51 +000060 for i in range(len(args)):
61 if string.find(args[i], ' ') != -1:
Greg Warde2b44522000-03-07 03:25:20 +000062 args[i] = '"%s"' % args[i]
Greg Warda3c8bf32000-03-26 21:47:00 +000063 return args
Greg Warde2b44522000-03-07 03:25:20 +000064
65def _spawn_nt (cmd,
66 search_path=1,
67 verbose=0,
68 dry_run=0):
69
Greg Ward69628b01999-08-29 18:20:56 +000070 executable = cmd[0]
Greg Warda30f7ac2000-09-26 02:00:51 +000071 cmd = _nt_quote_args(cmd)
Greg Ward69628b01999-08-29 18:20:56 +000072 if search_path:
Greg Ward88608ca2000-08-02 01:08:02 +000073 # either we find one or it stays the same
74 executable = find_executable(executable) or executable
Greg Ward69628b01999-08-29 18:20:56 +000075 if verbose:
Greg Warda30f7ac2000-09-26 02:00:51 +000076 print string.join([executable] + cmd[1:], ' ')
Greg Ward69628b01999-08-29 18:20:56 +000077 if not dry_run:
78 # spawn for NT requires a full path to the .exe
Greg Ward3b49c9b2000-01-17 21:57:55 +000079 try:
Greg Warda30f7ac2000-09-26 02:00:51 +000080 rc = os.spawnv(os.P_WAIT, executable, cmd)
Greg Ward3b49c9b2000-01-17 21:57:55 +000081 except OSError, exc:
82 # this seems to happen when the command isn't found
83 raise DistutilsExecError, \
84 "command '%s' failed: %s" % (cmd[0], exc[-1])
Greg Ward69628b01999-08-29 18:20:56 +000085 if rc != 0:
Greg Ward3b49c9b2000-01-17 21:57:55 +000086 # and this reflects the command running but failing
87 raise DistutilsExecError, \
88 "command '%s' failed with exit status %d" % (cmd[0], rc)
Greg Wardb4dbfb31999-08-14 23:57:17 +000089
Greg Ward69628b01999-08-29 18:20:56 +000090
Greg Wardb4dbfb31999-08-14 23:57:17 +000091def _spawn_posix (cmd,
92 search_path=1,
93 verbose=0,
94 dry_run=0):
95
96 if verbose:
Greg Warda30f7ac2000-09-26 02:00:51 +000097 print string.join(cmd, ' ')
Greg Wardb4dbfb31999-08-14 23:57:17 +000098 if dry_run:
99 return
100 exec_fn = search_path and os.execvp or os.execv
101
Greg Warda30f7ac2000-09-26 02:00:51 +0000102 pid = os.fork()
Greg Wardb4dbfb31999-08-14 23:57:17 +0000103
104 if pid == 0: # in the child
105 try:
106 #print "cmd[0] =", cmd[0]
107 #print "cmd =", cmd
Greg Warda30f7ac2000-09-26 02:00:51 +0000108 exec_fn(cmd[0], cmd)
Greg Wardb4dbfb31999-08-14 23:57:17 +0000109 except OSError, e:
Greg Warda30f7ac2000-09-26 02:00:51 +0000110 sys.stderr.write("unable to execute %s: %s\n" %
111 (cmd[0], e.strerror))
112 os._exit(1)
Greg Wardb4dbfb31999-08-14 23:57:17 +0000113
Greg Warda30f7ac2000-09-26 02:00:51 +0000114 sys.stderr.write("unable to execute %s for unknown reasons" % cmd[0])
115 os._exit(1)
Greg Wardb4dbfb31999-08-14 23:57:17 +0000116
117
118 else: # in the parent
119 # Loop until the child either exits or is terminated by a signal
120 # (ie. keep waiting if it's merely stopped)
121 while 1:
Greg Warda30f7ac2000-09-26 02:00:51 +0000122 (pid, status) = os.waitpid(pid, 0)
123 if os.WIFSIGNALED(status):
Greg Wardb4dbfb31999-08-14 23:57:17 +0000124 raise DistutilsExecError, \
Greg Ward3b49c9b2000-01-17 21:57:55 +0000125 "command '%s' terminated by signal %d" % \
Greg Warda30f7ac2000-09-26 02:00:51 +0000126 (cmd[0], os.WTERMSIG(status))
Greg Wardb4dbfb31999-08-14 23:57:17 +0000127
Greg Warda30f7ac2000-09-26 02:00:51 +0000128 elif os.WIFEXITED(status):
129 exit_status = os.WEXITSTATUS(status)
Greg Wardb4dbfb31999-08-14 23:57:17 +0000130 if exit_status == 0:
131 return # hey, it succeeded!
132 else:
133 raise DistutilsExecError, \
Greg Ward3b49c9b2000-01-17 21:57:55 +0000134 "command '%s' failed with exit status %d" % \
Greg Wardb4dbfb31999-08-14 23:57:17 +0000135 (cmd[0], exit_status)
136
Greg Warda30f7ac2000-09-26 02:00:51 +0000137 elif os.WIFSTOPPED(status):
Greg Wardb4dbfb31999-08-14 23:57:17 +0000138 continue
139
140 else:
141 raise DistutilsExecError, \
Greg Ward3b49c9b2000-01-17 21:57:55 +0000142 "unknown error executing '%s': termination status %d" % \
Greg Wardb4dbfb31999-08-14 23:57:17 +0000143 (cmd[0], status)
144# _spawn_posix ()
Greg Ward88608ca2000-08-02 01:08:02 +0000145
146
147def find_executable(executable, path=None):
148 """Try to find 'executable' in the directories listed in 'path' (a
149 string listing directories separated by 'os.pathsep'; defaults to
150 os.environ['PATH']). Returns the complete filename or None if not
151 found.
152 """
153 if path is None:
154 path = os.environ['PATH']
155 paths = string.split(path, os.pathsep)
156 (base, ext) = os.path.splitext(executable)
157 if (sys.platform == 'win32') and (ext != '.exe'):
158 executable = executable + '.exe'
159 if not os.path.isfile(executable):
160 for p in paths:
161 f = os.path.join(p, executable)
162 if os.path.isfile(f):
163 # the file exists, we have a shot at spawn working
164 return f
165 return None
166 else:
167 return executable
168
169# find_executable()