# _posixsubprocess - pydoc - phpman

Help on built-in module _posixsubprocess:

## NAME
    _posixsubprocess - A POSIX helper for the subprocess module.

## FUNCTIONS
### fork_exec
        fork_exec(args, executable_list, close_fds, pass_fds, cwd, env,
                  p2cread, p2cwrite, c2pread, c2pwrite,
                  errread, errwrite, errpipe_read, errpipe_write,
                  restore_signals, call_setsid,
                  gid, groups_list, uid,
                  preexec_fn)

        Forks a child process, closes parent file descriptors as appropriate in the
        child and dups the few that are needed before calling exec() in the child
        process.

        If close_fds is true, close file descriptors 3 and higher, except those listed
        in the sorted tuple pass_fds.

        The preexec_fn, if supplied, will be called immediately before closing file
        descriptors and exec.
        WARNING: preexec_fn is NOT SAFE if your application uses threads.
                 It may trigger infrequent, difficult to debug deadlocks.

        If an error occurs in the child process before the exec, it is
        serialized and written to the errpipe_write fd per subprocess.py.

        Returns: the child process's PID.

        Raises: Only on an error in the parent process.

## FILE
    (built-in)