use strict;
use warnings;

my $temp = "DATA\nFile\nHello\nAnother line\n";

my $found;

if( $temp =~ m/File\n(^.*$)/m ) {
    $found = $1;
    print $found, "\n";
}

##</code><code>##

my @lines = split /\n/, $temp;
foreach my $idx ( 0 .. $#lines ) {
    next unless $lines[ $idx ] =~ m/File/;
    $found = $lines[ $idx + 1 ];
    print $found;
    last;
}