ctime than its argument.
From kre in PR bin/14802; originally suggested name was "updated" but
renamed due to GNU find(1) being prior art for this functionality.
same name, match files' entire paths against regular expressions.
-regex is case sensitive, -iregex is case-insensitive. Note that these
primaries are _not_ entirely compatible with the GNU find primaries,
because their BREs appear to support alternation with \| whereas our BREs
do not. Also note there are no primaries which provide extended regular
expressions matching, though if they are desired they would be trivial
to implement.