os.py 文件源码

def popen4(cmd, mode="t", bufsize=-1):
            """Execute the shell command 'cmd' in a sub-process.  On UNIX, 'cmd'
            may be a sequence, in which case arguments will be passed directly to
            the program without shell intervention (as with os.spawnv()).  If 'cmd'
            is a string it will be passed to the shell (as with os.system()). If
            'bufsize' is specified, it sets the buffer size for the I/O pipes.  The
            file objects (child_stdin, child_stdout_stderr) are returned."""
            import warnings
            msg = "os.popen4 is deprecated.  Use the subprocess module."
            warnings.warn(msg, DeprecationWarning, stacklevel=2)

            import subprocess
            PIPE = subprocess.PIPE
            p = subprocess.Popen(cmd, shell=isinstance(cmd, basestring),
                                 bufsize=bufsize, stdin=PIPE, stdout=PIPE,
                                 stderr=subprocess.STDOUT, close_fds=True)
            return p.stdin, p.stdout