Process definition, parent-child relationships, process tree, real-world examples (server patterns)

fork(), exit(), wait(), execve() — lifecycle diagram, status macros, exec() family table

Why UNIX separates creation from execution, I/O redirection between fork and exec, posix_spawn()

Kernel steps, inherited vs unique attributes table, file locks not inherited, signal handler inheritance

The three return cases (-1/0/+PID), switch/case pattern, multiple children, safe_fork() wrapper

Stack/data/BSS/heap/text layout, t_fork.c from TLPI, heap independence, /proc memory viewing

footprint.c pattern, isolating leaky functions, returning results via exit status and pipes

3-layer file model diagram, shared vs unique properties, fork_file_sharing.c, coordinated writing

lseek() offset sharing, O_APPEND atomic writes, fcntl F_SETFL, independent re-open pattern

Pipe EOF problem, O_CLOEXEC/FD_CLOEXEC, close_all_fds_except() utility

CoW step-by-step, page table before/after diagram, fork timing benchmark, /proc RSS observation

Why text is always shared, r-xp permissions, /proc/PID/maps, shared library text pages

VSZ vs RSS explained, measuring CoW with /proc, Linux overcommit, minimize before fork

Historical context, what vfork() guarantees, signature, the only correct usage pattern

Complete comparison table, t_vfork.c from TLPI, parent suspension proof, benchmark

Safe vs dangerous actions, stdio double-flush bug, stack corruption, POSIX obsolescence

Indeterminate execution order, race condition demo, shared file race, why sleep() doesn’t fix it

Linux kernel version history, sched_child_runs_first tunable, multicore implications

SIGUSR1 pattern, sigsuspend() vs pause(), block-before-fork rule, mutual sync

fork_sig_sync.c from TLPI, pipe-based sync alternative, reusable sync helper, multiple children