Revert "kill: Fix argument handling for negative PIDs"
This reverts commit 79097e55.
Fixes #211 (closed)
Without this revert, kill calls: kill(0, SIGTERM) = 0 With this revert, kill calls: kill(-3550, SIGTERM) = 0
Not sure what happened between !77 (merged) and now, though... Maybe add an assert that atoi returns something other than 0 in the negative case?