From: Andreas Schwab Date: Sat, 10 Aug 2013 07:11:33 GMT Subject: Re: [PATCH v4] gc: reject if another gc is running, unless --force is given Message-ID: In-Reply-To: Duy Nguyen writes: > On Fri, Aug 9, 2013 at 11:29 PM, Andres Perera wrote: >> On Thu, Aug 8, 2013 at 6:35 AM, Nguyễn Thái Ngọc Duy wrote: >>> + uintmax_t pid; >> >> pid_t is always an signed type, therefore unintmax_t does not make >> sense as a catch all value > > I only catch real process id. In practice we don't have processes with > negative pid_t, do we? I can't find any document about this, but at > least waitpid seems to treat negative pid (except -1) just as an > indicator while the true pid is the positive counterpart. Negative pids are used for denoting process groups in various interfaces. No process can have a negative pid. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."