The external PID file, if configured, is currently generated with 600
permissions, which results from the umask setting in the postmaster. I
think it would be nicer if we could make that 644.
I have often dealt with scripts and such that look through PID files
in /var/run, and it's always annoying when some PID file is not readable
for some reason or no reason at all. (One simple benefit is that you
don't need extra privileges to check whether the process is alive.)
Almost all PID files on my system are world-readable now.
