Currently, process-watcher just manually polls /proc There are other, potentially better ways to watch processes.
Goals:
- Get exit code when process ends.
- Guarantee short-lived processes are found. (appear during sleep)
python-ptrace
Something like:
debugger = PtraceDebugger()
process = debugger.addProcess(pid, is_attached=False)
process.waitEvent()However, in Ubuntu and probably other distros, permissions are locked down by default.
sudo su -
echo 0 > /proc/sys/kernel/yama/ptrace_scope
A better way to grant permissions is with libcap-bin as described here
sudo apt-get install libcap2-bin
sudo setcap cap_sys_ptrace=eip /usr/bin/wineserver
Also, I worry that attaching the debugger may actually slow down the process you're watching or have other negative affects. And because wait blocks this technique requires some thought (threading?).
inotify does not support python3. Docs say it uses epoll. Some people say pyinotify is poorly written. The main critic wrote python-inotify as a replacement.
Advantage to inotify is process-watcher won't miss a process that spawns and ends in between checks.
Leaning toward inotify, but need to research file-system watching more.
On unix systems, os.kill(pid, 0) can be used to check if a PID is still running. However, it's only slightly faster than os.path.exists('/proc/PID') and suffers from PermissionError when the process is under a different PID. Code could be written to swap between implementations, but this is overoptimizing.