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Diffstat (limited to 'lib/python2.7/distutils/spawn.py')
| -rw-r--r-- | lib/python2.7/distutils/spawn.py | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/lib/python2.7/distutils/spawn.py b/lib/python2.7/distutils/spawn.py new file mode 100644 index 0000000..7306099 --- /dev/null +++ b/lib/python2.7/distutils/spawn.py @@ -0,0 +1,199 @@ +"""distutils.spawn + +Provides the 'spawn()' function, a front-end to various platform- +specific functions for launching another program in a sub-process. +Also provides the 'find_executable()' to search the path for a given +executable name. +""" + +__revision__ = "$Id$" + +import sys +import os + +from distutils.errors import DistutilsPlatformError, DistutilsExecError +from distutils import log + +def spawn(cmd, search_path=1, verbose=0, dry_run=0): + """Run another program, specified as a command list 'cmd', in a new process. + + 'cmd' is just the argument list for the new process, ie. + cmd[0] is the program to run and cmd[1:] are the rest of its arguments. + There is no way to run a program with a name different from that of its + executable. + + If 'search_path' is true (the default), the system's executable + search path will be used to find the program; otherwise, cmd[0] + must be the exact path to the executable. If 'dry_run' is true, + the command will not actually be run. + + Raise DistutilsExecError if running the program fails in any way; just + return on success. + """ + if os.name == 'posix': + _spawn_posix(cmd, search_path, dry_run=dry_run) + elif os.name == 'nt': + _spawn_nt(cmd, search_path, dry_run=dry_run) + elif os.name == 'os2': + _spawn_os2(cmd, search_path, dry_run=dry_run) + else: + raise DistutilsPlatformError, \ + "don't know how to spawn programs on platform '%s'" % os.name + +def _nt_quote_args(args): + """Quote command-line arguments for DOS/Windows conventions. + + Just wraps every argument which contains blanks in double quotes, and + returns a new argument list. + """ + # XXX this doesn't seem very robust to me -- but if the Windows guys + # say it'll work, I guess I'll have to accept it. (What if an arg + # contains quotes? What other magic characters, other than spaces, + # have to be escaped? Is there an escaping mechanism other than + # quoting?) + for i, arg in enumerate(args): + if ' ' in arg: + args[i] = '"%s"' % arg + return args + +def _spawn_nt(cmd, search_path=1, verbose=0, dry_run=0): + executable = cmd[0] + cmd = _nt_quote_args(cmd) + if search_path: + # either we find one or it stays the same + executable = find_executable(executable) or executable + log.info(' '.join([executable] + cmd[1:])) + if not dry_run: + # spawn for NT requires a full path to the .exe + try: + rc = os.spawnv(os.P_WAIT, executable, cmd) + except OSError, exc: + # this seems to happen when the command isn't found + raise DistutilsExecError, \ + "command '%s' failed: %s" % (cmd[0], exc[-1]) + if rc != 0: + # and this reflects the command running but failing + raise DistutilsExecError, \ + "command '%s' failed with exit status %d" % (cmd[0], rc) + +def _spawn_os2(cmd, search_path=1, verbose=0, dry_run=0): + executable = cmd[0] + if search_path: + # either we find one or it stays the same + executable = find_executable(executable) or executable + log.info(' '.join([executable] + cmd[1:])) + if not dry_run: + # spawnv for OS/2 EMX requires a full path to the .exe + try: + rc = os.spawnv(os.P_WAIT, executable, cmd) + except OSError, exc: + # this seems to happen when the command isn't found + raise DistutilsExecError, \ + "command '%s' failed: %s" % (cmd[0], exc[-1]) + if rc != 0: + # and this reflects the command running but failing + log.debug("command '%s' failed with exit status %d" % (cmd[0], rc)) + raise DistutilsExecError, \ + "command '%s' failed with exit status %d" % (cmd[0], rc) + +if sys.platform == 'darwin': + from distutils import sysconfig + _cfg_target = None + _cfg_target_split = None + +def _spawn_posix(cmd, search_path=1, verbose=0, dry_run=0): + log.info(' '.join(cmd)) + if dry_run: + return + exec_fn = search_path and os.execvp or os.execv + exec_args = [cmd[0], cmd] + if sys.platform == 'darwin': + global _cfg_target, _cfg_target_split + if _cfg_target is None: + _cfg_target = sysconfig.get_config_var( + 'MACOSX_DEPLOYMENT_TARGET') or '' + if _cfg_target: + _cfg_target_split = [int(x) for x in _cfg_target.split('.')] + if _cfg_target: + # ensure that the deployment target of build process is not less + # than that used when the interpreter was built. This ensures + # extension modules are built with correct compatibility values + cur_target = os.environ.get('MACOSX_DEPLOYMENT_TARGET', _cfg_target) + if _cfg_target_split > [int(x) for x in cur_target.split('.')]: + my_msg = ('$MACOSX_DEPLOYMENT_TARGET mismatch: ' + 'now "%s" but "%s" during configure' + % (cur_target, _cfg_target)) + raise DistutilsPlatformError(my_msg) + env = dict(os.environ, + MACOSX_DEPLOYMENT_TARGET=cur_target) + exec_fn = search_path and os.execvpe or os.execve + exec_args.append(env) + pid = os.fork() + + if pid == 0: # in the child + try: + exec_fn(*exec_args) + except OSError, e: + sys.stderr.write("unable to execute %s: %s\n" % + (cmd[0], e.strerror)) + os._exit(1) + + sys.stderr.write("unable to execute %s for unknown reasons" % cmd[0]) + os._exit(1) + else: # in the parent + # Loop until the child either exits or is terminated by a signal + # (ie. keep waiting if it's merely stopped) + while 1: + try: + pid, status = os.waitpid(pid, 0) + except OSError, exc: + import errno + if exc.errno == errno.EINTR: + continue + raise DistutilsExecError, \ + "command '%s' failed: %s" % (cmd[0], exc[-1]) + if os.WIFSIGNALED(status): + raise DistutilsExecError, \ + "command '%s' terminated by signal %d" % \ + (cmd[0], os.WTERMSIG(status)) + + elif os.WIFEXITED(status): + exit_status = os.WEXITSTATUS(status) + if exit_status == 0: + return # hey, it succeeded! + else: + raise DistutilsExecError, \ + "command '%s' failed with exit status %d" % \ + (cmd[0], exit_status) + + elif os.WIFSTOPPED(status): + continue + + else: + raise DistutilsExecError, \ + "unknown error executing '%s': termination status %d" % \ + (cmd[0], status) + +def find_executable(executable, path=None): + """Tries to find 'executable' in the directories listed in 'path'. + + A string listing directories separated by 'os.pathsep'; defaults to + os.environ['PATH']. Returns the complete filename or None if not found. + """ + if path is None: + path = os.environ['PATH'] + paths = path.split(os.pathsep) + base, ext = os.path.splitext(executable) + + if (sys.platform == 'win32' or os.name == 'os2') and (ext != '.exe'): + executable = executable + '.exe' + + if not os.path.isfile(executable): + for p in paths: + f = os.path.join(p, executable) + if os.path.isfile(f): + # the file exists, we have a shot at spawn working + return f + return None + else: + return executable |