Linux System Calls

What Does the fork() System Call Do?

fork() creates a new process by duplicating the calling process almost exactly, returning twice — once in the parent with the child’s process ID, and once in t…

What Does the exec() Family of System Calls Do?

exec() replaces the calling process’s memory image — code, data, stack, and heap — with a new program loaded from disk, keeping the same process ID while compl…

What Does the wait() System Call Do?

wait() suspends the calling parent process until one of its child processes terminates, then reaps that child’s exit status and releases the kernel resources s…

What is an Orphan Process?

An orphan process is a still-running child process whose parent has terminated before it, causing the operating system to reparent it to the init process (PID…

What is a Daemon Process?

A daemon process is a long-running background process, detached from any controlling terminal, that starts (often at boot) and keeps running indefinitely to pr…