my $data = "Exlief 4    page : 1 /10";

if ($data =~ /pag[^:]*:\s*(\d+)[^\d]*(\d*)/) {
                    print "Pages : $1 / $2\n";
            }

my $data = "Exlief 4    page : 1 / 5";

if ($data =~ /pag[^:]*:\s*(\d+)[^\d]*(\d*)/) {
                    print "Pages : $1 / $2\n";
            }

output:
Pages : 1 / 10
Pages : 1 / 5