`pgrep -f FIFA17.exe` matched the remote shell executing it -- the SSH command line
contains the literal pattern -- so fifa_running() always returned True and the port
switcher could never edit openfut.cfg. It refused with "REFUSING to edit ... while a
FIFA client is running" moments after FIFA had actually exited.
Fail-closed, so nothing unsafe happened, but the guard was permanently stuck and
blocked the A/B entirely.
Now matches /proc/<pid>/comm exactly, which is the executable name: the invoking
shell reads as zsh and cannot self-match, while a genuine FIFA process still does.
Validated both directions with the same loop -- it found pid 36958 while FIFA was up,
and reports gone once it exited. Still fail-closed on read errors.
The lesson generalises: a pattern-matching process guard checked over a transport
that carries the pattern in its own argv is self-satisfying, and a guard that can
only ever say "yes" is not a guard.
funman300
fbe29da05b