Python os.WIFEXITED()方法

Python中的os.WIFEXITED()方法用于使用exit(2)系统调用检查进程是否退出。此方法以os.system()，os.wait()或os.waitpid()方法返回的进程状态码作为参数，如果进程使用exit(2)系统调用退出则返回True，否则返回False。

os.WIFEXITED 语法

os.WIFEXITED(status) 

os.WIFEXITED(status) 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:如果进程使用exit(2)系统调用退出，该方法返回True，否则返回False。

os.WIFEXITED(status) 示例1

os.WIFEXITED()方法的使用

# Python program to explain os.WIFEXITED() method 
  
# importing os module  
import os
  
# Create a child process
# using os.fork() method 
pid = os.fork()
  
  
# pid greater than 0
# indicates the parent process 
if pid > 0:
  
    # Create one more child
    pid2 = os.fork()
      
    if pid2 > 0:
          
        print("\nIn parent process")
        # Wait for the completion 
        # of first child process and    
        # get its pid and 
        # exit status indication using
        # os.waitpid() method
        info1 = os.waitpid(pid, 0)
  
          
        # Wait for the completion 
        # of second child process and    
        # get its pid and 
        # exit status indication using
        # os.waitpid() method
        info2 = os.waitpid(pid2, 0)
  
          
        # os.waitpid() method returns a tuple
        # first attribute represents child's pid
        # while second one represents
        # exit status indication
  
        # Check if the first child 
        # exited using exit(2) system call
        # using os.WIFEXITED() method
        if os.WIFEXITED(info1[1]) :
            print("First child exited using exit(2) system call.")
        else :
            print("First child does not exited using \
exit(2) system call.") 
          
      
        # Check if the second child 
        # exited using exit(2) system call
        # using os.WIFEXITED() method
        if os.WIFEXITED(info2[1]) :
            print("Second child exited using exit(2) system call.")
        else :
            print("Second child does not exited using \
exit(2) system call.") 
          
      
           
    else :
        print("\nIn second child process")
        print("Process ID:", os.getpid())
        print("Hey ! there")
        print("Second child aborted")
  
        # os.abort() method will
        # generate a SIGABRT signal
        # to the current process.
        os.abort()    
  
else :
    print("In first child process")
    print("Process ID:", os.getpid())
    print("Hello ! Geeks")
    print("First child exiting..")
      
    # Exit using exit(2) system call        
    os._exit(5)

输出:

In first child process
Process ID: 11614
Hello! Geeks
First child exiting..

In second child process
Process ID: 11615
Hey! there
Second child aborted

In parent process
First child exited using exit(2) system call.
Second child does not exited using exit(2) system call.