Why does GNU
chown user.group work? The docs say nothing of the syntax being supported. Is there a juicy story behind it?
info chown is clear on that:
Some older scripts may still use `.' in place of the `:' separator. POSIX 1003.1-2001 (*note Standards conformance::) does not require support for that, but for backward compatibility GNU `chown' supports `.' so long as no ambiguity results. New scripts should avoid the use of `.' because it is not portable, and because it has undesirable results if the entire OWNER`.'GROUP happens to identify a user whose name contains `.'.
In case of
GNU programs it's often worth checking not only
man but also
info pages because GNU folks abhor manpages (from