Cloudef / pid-defer

Run processes that will be cleaned up when other process exits. (Linux only)

pid-defer

Run processes that will be cleaned up when other process exits. (Linux only)

---

Project is tested on zig version 0.12.0-dev.2058+04ac028a2

How to use

Common problem with shell scripts is wanting to have background processes that needs to be cleaned up when some arbitary main process exits. This project tries to solve that problem, acting as sort of local service / process handler.

defer ppid my-command [args]

Warning

It's possible for a race condition to occur if ppid dies and is replaced by other process with same pid before defer calls pidfd_open.

Example

defer $$ watch -t -x echo "this is gonna go away in 5 seconds (hopefully)"
sleep 5
# defer and watch -t -x should exit now

Handling double forking processes

When child double forks itself or spawns other children that might double fork, you can use the reaper binary to handle those.

defer $$ reaper daemonize -o /dev/stdout "$(which watch)" -t -x echo "this is gonna go away in 5 seconds (hopefully)"
sleep 5
# defer, reaper and watch -t -x should exit now

waitpid

This repo also offers extra tool called waitpid. It does exactly what the name says.

echo "sleeping for 5 secs now"
sleep 5 &
waitpid $!
echo "okay did we wait for the sleep properly?"