use Modern::Perl;

open my $FH, '<', '/home/jack/Desktop/Perl_file.txt' or die "Could not open file: $!";

while (my $line = <$FH>) {
    next unless $line =~ m/\S/; # loop again unless line contains at least one non-white-space character
    my $char = substr($line, 0, 2);
    print $char;
}

close $FH;
##</code><code>##

print map substr($_, 0, 2),  grep  m/\S/,  <$FH>;