/the ps command itself really isn't portable/a
.
.,/^  *[^# ]/-1d
/`ps h o pid p $$`[^)]*/s,,system("ps -p $$ >/dev/null") == 0 ,
/`ps h o pid p $current_pid`/s,,( system("ps -p $current_pid >/dev/null" ) == 0),
w