Python| os.WIFSTOPPED() 方法

Python中的OS 模块提供了与操作系统交互的功能。操作系统属于 Python 的标准实用程序模块。该模块提供了一种使用操作系统相关功能的可移植方式。

Python中的os.WIFSTOPPED()方法用于检查进程是否已停止。该方法将os.wait() 、 os.system()或os.waitpid()方法返回的进程状态码作为参数，如果进程已停止则返回 True，否则返回 False。

Syntax: os.WIFSTOPPED(status)

Parameter:
status: This parameter takes process status code (an integer value) as returned by os.system(), os.wait() or os.waitpid() method.

Return type: This method returns a boolean value of class ‘bool’. This method returns True if the process has been stopped, otherwise returns False.

代码：使用os.WIFSTOPPED()方法

# Python program to explain os.WIFSTOPPED() method 
  
# importing os and signal module  
import os, signal
  
# Create a child process
# using os.fork() method 
pid = os.fork()
  
  
# pid greater than 0
# indicates the parent process 
if pid :
      
    # Send signal 'SIGSTOP'
    # to child process
    # using os.kill() method
    # signal will cause the child
    # process to stop
    os.kill(pid, signal.SIGSTOP)
          
    # Get the child's pid and 
    # status code using
    # os.waitpid() method
    info = os.waitpid(pid, os.WSTOPPED)
  
    # info is a tuple
    # info[0] represents child's pid
    # info[1] represents exit status code
  
    print("\nIn parent process")
      
    # Check whether the child process
    # has been stopped or not    
    # using os.WIFSTOPPED() method
    isStopped = os.WIFSTOPPED(info[1]) 
  
    print("Has child process been stopped?")
    print(isStopped)
  
  
else :
    print("In Child process")
    print("Process ID:", os.getpid())
    print("Hello ! Geeks")
     

输出：

In Child process
Process ID: 10224
Hello! Geeks

In parent process
Has child process been stopped?
True

参考资料： https://docs。 Python.org/3/library/os.html#os.WIFSTOPPED