Hi,

Here is a very common usecase:

sudo chgrp www-data dir

in a deployment script.

I have always used "sudo" with this because I didn't know why I was getting
an operation permitted error when doing so. Until I found out that if the
effective user is a member of the target group www-data, the sudo isn't
needed.

The Wikipedia clearly says that:

The *chgrp* (from *ch*ange *gr*ou*p*)
command<http://en.wikipedia.org/wiki/Command_(computing)> may
be used by unprivileged
<http://en.wikipedia.org/wiki/Privilege_(Computing)> users
on Unix-like <http://en.wikipedia.org/wiki/Unix-like> systems to change the
group associated with a file system object (such as a file, directory, or
link) *to one of which they are a member*.

I am wondering why the chgrp manpage or info pages do not mention anything
about that. It would be very helpful to add that piece of very crucial
information to the manpage/info pages.

Best regards,

-- 
Wouter Thielen