Python | os.WIFEXITED() method

OS module in Python provides functions for interacting with the operating system. OS comes under Python’s standard utility modules. This module provides a portable way of using operating system dependent functionality.

os.WIFEXITED() method in Python is used to check whether the process exited using exit(2) system call. This method takes process status code as returned by os.system(), os.wait() or os.waitpid() method as parameter and returns True if the process exited using exit(2) system call, otherwise returns False.

Syntax: os.WIFEXITED(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 True if the process exited using exit(2) system call else returns False.

Code: Use of os.WIFEXITED() method

# 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)

Output:

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.

References: https://docs.python.org/3/library/os.html#os.WIFEXITED