my @files = <*.HTM>;
foreach $file (@files) {
if ($file =~ m/IDX/gi){print $file."\n";}
} 

##</code><code>##

ACIDX.HTM
APIDX.HTM
...

##</code><code>##

my @files = <*.HTM>;
foreach $file (@files) {
if ($file = ~m/IDX/gi){print $file."\n";}
} 

##</code><code>##

4294967295
4294967295
...