Which system call is used to obtain the parent process ID?

Which system call is used to obtain the parent process ID?

• A. Getppid
• B. Getpid
• C. Fork
• D. Exit

Answer: (A)

To obtain the parent process ID, you use getppid(). This function asks the kernel for the parent ID of the process that is currently running and returns it as a pid_t. It’s different from getpid(), which gives you the current process’s own ID. The other options serve different purposes: one creates a new process and returns a value that distinguishes the parent from the child, and the last ends the process. Remember also that if the parent exits, the system may adopt the process to the init (or systemd) process, so the parent ID could become 1.

To obtain the parent process ID, you use getppid(). This function asks the kernel for the parent ID of the process that is currently running and returns it as a pid_t. It’s different from getpid(), which gives you the current process’s own ID. The other options serve different purposes: one creates a new process and returns a value that distinguishes the parent from the child, and the last ends the process. Remember also that if the parent exits, the system may adopt the process to the init (or systemd) process, so the parent ID could become 1.