Eric Blake <[EMAIL PROTECTED]> wrote: > According to Paul Eggert on 9/11/2008 11:56 AM: >> >> As I read the spec, chown and chgrp are explicitly required to make >> the equivalent of a chown() call, which in turn is required to change >> the ctime. However, chmod is not required to make the equivalent of a >> chmod() call, and there is no requirement in the 'chmod' spec that it >> change the ctime. So POSIX allows the optimization for the 'chmod' >> command, but not for the 'chown' and 'chgrp' commands. > > On the other hand, the POSIX spec for chmod(1) mentions that it is > implementation defined on how it affects alternate access control. I have > come to expect on many systems that support ACLs, that 'chmod 755' on a > file with rwxr-xr-x+ permissions will remove the ACLs. In other words, > optimizing away the chmod(2) call because it compares equal to the stat > information would break this side-effect of clearing ACLs.
That sounds like a good reason to retain the behavior you've come to value, even if it's not guaranteed or portable, but only via a new option. Then we can still change the default to be more efficient. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
