in reply to noob regexpression question

Although not a *compile* error, you should replace m/exe/ and m/dll/ with m/\.exe$/i and m/\.dll$/i.

By the way, the following is equivalent (minus the prints) to your code:

chomp(@exeDllLines);
my @dllarray = grep { /\.(?:dll|exe)$/i } @exeDllLines;

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or the more memory-efficient 
chomp(@exeDllLines);

my @dllarray;
foreach (@exeDllLines) {
   push @dllarray, $_ if /\.(?:dll|exe)$/i;
}

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Update: Oops, not quite. I didn't see the square brackets around DLLs.

In Section Seekers of Perl Wisdom