use 5.014;
use warnings;
use Time::HiRes qw(usleep ualarm gettimeofday tv_interval);

my @array;
my $pattern = '\bsala|che|relazione|di|questo|coso|^qui\$';
open( my $filehandle, "<textMatchInAfile.txt" );
my $time = [gettimeofday];
while (<$filehandle>) {
    if ( $_ =~ /$pattern/ ) {
        push @array;
    }
}
say 'time while' . tv_interval($time);