ptyprocess.py 文件源码

def wait(self):
        '''This waits until the child exits. This is a blocking call. This will
        not read any data from the child, so this will block forever if the
        child has unread output and has terminated. In other words, the child
        may have printed output then called exit(), but, the child is
        technically still alive until its output is read by the parent. '''

        if self.isalive():
            pid, status = os.waitpid(self.pid, 0)
        else:
            return self.exitstatus
        self.exitstatus = os.WEXITSTATUS(status)
        if os.WIFEXITED(status):
            self.status = status
            self.exitstatus = os.WEXITSTATUS(status)
            self.signalstatus = None
            self.terminated = True
        elif os.WIFSIGNALED(status):
            self.status = status
            self.exitstatus = None
            self.signalstatus = os.WTERMSIG(status)
            self.terminated = True
        elif os.WIFSTOPPED(status):  # pragma: no cover
            # You can't call wait() on a child process in the stopped state.
            raise PtyProcessError('Called wait() on a stopped child ' +
                    'process. This is not supported. Is some other ' +
                    'process attempting job control with our child pid?')
        return self.exitstatus