You may be right. Certainly the regex you envision would be a tad clumsy. :)

At the moment, it's looking to me as though I should have written the code to support my claim re regex solutions, before posting, rather than simply doing a mental sketch (which proved to be wrong in at least that particular instance). Thank you for making me "think, again!"

However, on the theory that simple (or, in this case, 'concise') is desirable:

#!/usr/bin/perl
use 5.014;
# 972317
my @arr1 = ('C:\abc\def\zz456','C:\abc\xyz\ab123','C:\abb\bba\ac234','
+C:\abc\xyz\ab321');
my @arr2 = qw/ab123 ac234 ad456 ab321/;              # no match for C:
+\abc\def\zz456
my $dir_entry;

my @arr3 = grep { $dir_entry = $_; not grep { $dir_entry =~ /\Q$_/i } 
+@arr2 } @arr1;

say "Following is/are dir entry/entries (in \$arr1) without matching i
+tems in \@arr2";
say each(@arr3);

[download]

Output ( index and array element; see each ):
0C:\abc\def\zz456

And can some knowledgeable Monk explain why the index of the zeroth element of the array is rendered as 0C?

Update: A knowledgeable Monk (++) has indeed explained... and the answer has little to do with the assumption immediately above. Meh! Blech on me.

In reply to Re^3: Memory issue with large array comparison by ww
in thread Memory issue with large array comparison by bholcomb86

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