LEC-13: wait() & waitpid() System Calls | Orphan & Zombie Processes | Linux System Programming. скачать в хорошем качестве

LEC-13: wait() & waitpid() System Calls | Orphan & Zombie Processes | Linux System Programming.

In Lecture 13 of Linux System Programming, we cover one of the most important and frequently asked topics in Linux interviews — process termination, wait() and waitpid() system calls, and orphan and zombie processes. This lecture builds directly on previous concepts like fork() system call and process creation, completing your understanding of Linux process lifecycle. When a process terminates in Linux, the kernel must properly clean up its resources. If this is not handled correctly, zombie processes and orphan processes are created. Understanding how and why this happens is critical for system programmers, embedded Linux developers, and Linux administrators. What You Will Learn in This Lecture This lecture explains all concepts from basics to internals with real examples: ✔ What happens when a process terminates in Linux ✔ Parent–child relationship recap using fork() ✔ What is the wait() system call ✔ Syntax and return value of wait() ✔ How parent collects child exit status ✔ Decoding exit status using macros (WIFEXITED, WEXITSTATUS, etc.) ✔ What is the waitpid() system call ✔ Difference between wait() and waitpid() ✔ Blocking vs non-blocking wait (WNOHANG) ✔ How to wait for a specific child process ✔ What is a zombie process ✔ How zombie processes are created ✔ How to detect zombie processes using ps command ✔ What is an orphan process ✔ How orphan processes are created ✔ Role of init / systemd in adopting orphan processes ✔ How to avoid zombie processes in real applications 🔹 Zombie vs Orphan Process Explained Clearly This lecture clearly explains the difference between zombie and orphan processes, a topic that often confuses beginners: Zombie Process: Child has terminated, but parent has not called wait() Orphan Process: Parent terminates before child, child is adopted by init/systemd With live code execution and terminal output, you will see how these processes appear in real Linux systems. Keywords: wait system call waitpid system call wait vs waitpid zombie process in linux orphan process in linux linux system programming process termination in linux linux process management zombie and orphan process explained wait system call in linux waitpid with example linux c programming wait linux internals process child process termination linux parent child process linux linux process lifecycle linux system calls embedded linux programming free embedded systems course linux programming tutorial blocking vs non blocking wait WNOHANG waitpid zombie process example orphan process example ps command zombie process linux interview questions processes system programming in c linux multitasking linux os internals linux device drivers basics