#!/usr/bin/perl
use strict;
use warnings;
# 839761

my @foo=("a.jpg", "b.txt", "Cde.jpg", "abc.jpg.delete_everything.exe", "123.jpg", "|#&.exe");
print "Using negative match, '!~'- items which match should be excluded:\n\n";

for my $item(@foo) { 
	if ($item !~/^[A-Z0-9]+\.jpg$/i) {
		print "\t--> (negated) match: $item \n";
	}else{
	print "no match in \$item: $item \n";
	}
}
print "\n\n". 'Now using /^[A-Z0-9]+\..+$/i' . " so matched should be accepted: \n\n";
for my $item(@foo) { 
	if ($item =~/^[A-Z0-9]+\.jpg$/i) {
		print "\t --> match: $item \n";
	}else{
	print "no match in \$item: $item \n";
	}
}