Checking in a bunch of spawn functions. These are only defined if we
have fork and execv (and friends) but not spawnv. They operate
exactly like the spawn functions on Windows. A limited set of needed
constants is also defined (P_WAIT, P_NOWAIT etc.).
Also add getenv() as a familiar alias for environ.get().
diff --git a/Lib/os.py b/Lib/os.py
index e99ce2a..8836dd3 100644
--- a/Lib/os.py
+++ b/Lib/os.py
@@ -201,8 +201,8 @@
_execvpe(file, args, env)
_notfound = None
-def _execvpe(file, args, env = None):
- if env:
+def _execvpe(file, args, env=None):
+ if env is not None:
func = execve
argrest = (args, env)
else:
@@ -273,3 +273,81 @@
self.data[key] = item
environ = _Environ(environ)
+
+def getenv(key, default=None):
+ """Get an environment variable, return None if it doesn't exist.
+
+ The optional second argument can specify an alternative default."""
+ return environ.get(key, default)
+
+def _exists(name):
+ try:
+ eval(name)
+ return 1
+ except NameError:
+ return 0
+
+# Supply spawn*() (probably only for Unix)
+if _exists("fork") and not _exists("spawnv") and _exists("execv"):
+
+ P_WAIT = 0
+ P_NOWAIT = P_NOWAITO = 1
+
+ # XXX Should we support P_DETACH? I suppose it could fork()**2
+ # and close the std I/O streams. Also, P_OVERLAY is the same
+ # as execv*()?
+
+ def _spawnvef(mode, file, args, env, func):
+ # Internal helper; func is the exec*() function to use
+ pid = fork()
+ if not pid:
+ # Child
+ try:
+ if env is None:
+ func(file, args)
+ else:
+ func(file, args, env)
+ except:
+ _exit(127)
+ else:
+ # Parent
+ if mode == P_NOWAIT:
+ return pid # Caller is responsible for waiting!
+ while 1:
+ wpid, sts = waitpid(pid, 0)
+ if WIFSTOPPED(sts):
+ continue
+ elif WIFSIGNALED(sts):
+ return -WTERMSIG(sts)
+ elif WIFEXITED(sts):
+ return WEXITSTATUS(sts)
+ else:
+ raise error, "Not stopped, signaled or exited???"
+
+ def spawnv(mode, file, args):
+ return _spawnvef(mode, file, args, None, execv)
+
+ def spawnve(mode, file, args, env):
+ return _spawnvef(mode, file, args, env, execve)
+
+ # Supply the various other variants
+
+ def spawnl(mode, file, *args):
+ return spawnv(mode, file, args)
+
+ def spawnle(mode, file, *args):
+ env = args[-1]
+ return spawnve(mode, file, args[:-1], env)
+
+ def spawnlp(mode, file, *args):
+ return spawnvp(mode, file, args)
+
+ def spawnlpe(mode, file, *args):
+ env = args[-1]
+ return spawnvpe(mode, file, args[:-1], env)
+
+ def spawnvp(mode, file, args):
+ return _spawnvef(mode, file, args, None, execvp)
+
+ def spawnvpe(mode, file, args, env):
+ return _spawnvef(mode, file, args, env, execvpe)