diff options
| -rw-r--r-- | Lib/os.py | 82 |
1 files changed, 80 insertions, 2 deletions
@@ -201,8 +201,8 @@ def execvpe(file, args, env): _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 @@ else: 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) |