#!/usr/bin/perl

use warnings;
use strict;

use File::Find;

open my $log, '>', 'log.txt'
  or die "Can't open the log file!: $!";

find(\&check_data, "./test");

sub check_data {
    
    my $file = $_; #for clarity

    return if ! -f $file;

    open my $fh, '<', $file
      or die "Can't open file $file: $!";

    for my $line (<$fh>){
        if ($line =~ /^HELLO/){
            my @parts = split(/\//, $line);
            for my $index (qw(1 3 4)){
                if (! $parts[$index] or $parts[$index] =~ /[\s+-]/){
                    print $log "$file is missing data.\n";
                    return
                }
            }
        }
    }
}

##</code><code>##

$ cat test/hello.pl
adsfasdfasdf
HELLO/asdf/asdf/asdf/asdf/asdf

$ cat test/testing.txt 
asdfasdf/dfasdf/12351234132r
HELLO/asdf//////////

##</code><code>##

$ cat log.txt 
testing.txt is missing data.