There's an entry in perlfaq4, which comes with perl (try `perldoc perlfaq4` or `perldoc -q round` at the command line prompt): "Does Perl have a round() function? What about ceil() and floor()? Trig functions?" which says to use sprintf. Note that for rounding to the nearest integer, you must use

sprintf "%.0f", $n

not

sprintf "%d", $n

The latter "rounds towards zero" (AKA "truncate"), just like int does.

It seems strange to me that POSIX (a standard module) implements ceil() and floor() and zillions of (mathematical and other) functions, doesn't seem to include a round() function.