Python os.WIFSTOPPED()方法

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

os.WIFSTOPPED 语法

os.WIFSTOPPED(status) 

os.WIFSTOPPED 参数

status:该参数接受进程状态码(一个整数值)，由os.system()，os.wait()或os.waitpid()方法返回。

返回类型:该方法返回一个布尔值，类为’bool’。如果进程已经停止，此方法返回True，否则返回False。

os.WIFSTOPPED 示例

os.WIFSTOPPED()方法的使用

# 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