I figure you still have some indenting work to do. This is very important. Judiciously applied white space is one of the very most important things that you can do to improve readability of your code.

Untested, but I figure close to what you want...test, experiment, move forward with the advice you've gotten so far... 

my $num_errors = 0;
foreach my $file (keys %hash1)
{
   if (!exists ($hash2{$file}) )
   {
       print "file: $file doesn't exist in 2nd directory\n";
   }
   elsif ($hash1{$file} ne $hash2{$file})
   {
       print "md5 didn't match for $file\n";
          # meaning that file in 2nd directory is not the 
          # same as the file in 1st directory
       $num_errors++;
   }
}
print "total errors = $num_errors\n";

[download]
Perl "sees" something akin to this (below)... a bit harder to understand than the above?
white space is important, variable names are important.
I called my hashes %dirA and %dirB instead of %hash1 and %hash2 for a reason!

%x is a hash but "x" has no contextual meaning! %dirA is a hash of file names in directory A to checksums.
Even %dirA_files_to_checksums would be wayyyyyy better than %hash1. I guess %dir1 is also ok. The % means hash - give more contextual information! 

my $num_errors=0;foreach my $file (keys %hash1){if (!exists ($hash2{$f
+ile})){print "file: $file doesn't exist in 2nd directory\n";}elsif ($
+hash1{$file} ne $hash2{$file}){print "md5 didn't match for $file\n";$
+num_errors++;}}print "total errors = $num_errors\n";

[download]
PS: Yes, a hash tables for this purpose is going to be WAY more efficient than an array.

In reply to Re^3: Global variables question by Marshall
in thread Global variables question by PerlScholar

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.