Adding to other monks' comments, I can see two problems with your code:

1) while (<$fh>) { ...
This will break if the first line of the file is 0, the second line will not be read.

2) return $fields[2] =~ /.../;
What if the array @fields is empty? You will get warnings (assume you had 'use warnings' in your code, or haven't you?)

So I would suggest to add more error checking to the code to make it more robust.
sub check_field {
    my $file_name = shift;

    open my $fh, "<$file_name"
        or die "*** ERROR opening '$file_name': $!";

    my @fields = ();

    while (defined (<$fh>)) {
       if ($. == 2) {
           chomp;
           @fields = split /;/;
           return 0 unless $#fields == 3;
           last;
       }
    }

    return 0 if $#fields < 0;
    return $fields[2] =~ /^\d+$/;
}

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In reply to Re: advice for reading data from a file by Roger
in thread advice for reading data from a file by Anonymous Monk

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