The POSIX module contains functions called ceil and floor which return the first integer greater or less than a given number.

#!/usr/bin/perl -w
use strict;

use POSIX qw(ceil floor);

my @numbers = qw(1 1.2 1.5 1.7 -1.2 -1.5 -1.7);

foreach (@numbers) {
  printf("x: %.1f: ceil(x): %d floor(x) %d\n", 
         $_, ceil($_), floor($_));
}
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<http://www.dave.org.uk>

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and the boring jobs bearable" - me