Order the daemonisation steps

Challenge

The canonical daemonise sequence has 7 steps. Implement int daemonize_step_after(int current) returning the step that follows current, or -1 if current is the last step. Step numbers:

• 1 = first fork (parent exits)
• 2 = setsid in child
• 3 = second fork
• 4 = chdir /
• 5 = umask 0
• 6 = close stdin/stdout/stderr
• 7 = reopen them on /dev/null

Why this matters

The classic 'double-fork daemonise' has a precise ordering; reordering breaks the daemon's properties (won't survive logout, leaves a controlling terminal, etc).

Input format

Current step number.

Output format

Next step (or -1).

Constraints

Pure lookup.

Starter code

int daemonize_step_after(int current) { /* TODO */ (void)current; return -1; }

Common mistakes

Swapping setsid before fork (kills the daemon's reparent).

Edge cases to handle

Invalid current step.

Complexity

O(1).

Background lessons

• fork — duplicating the process
• exec — replacing the process image
• wait and waitpid