$ perl -wE 'say scalar glob "NONEXISTENT*"'
Use of uninitialized value in say at -e line 1.
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($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
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scalar glob

Yes, sorry, I wrote too hastily and was thinking in the context of the code I showed, updated. Thanks for pointing that out!

I am attaching you the full code that I am executing. Here for every input files I am parsing lines starting with / RULECHECK/ .In each line there are 8 set of entries separated by spaces but i have to insert only 2 and 8th entry in output.txt

#!/usr/local/bin/perl -w
open (OUT, ">output.txt");

use warnings;
use strict;
#use Data::Dump; # Debug
use File::Basename qw/fileparse/;
use File::stat;

my %filelist;
for my $file (glob '/user/*/ws/*/BLK_*/*.txt') {
    my $bn = fileparse($file);
    my $mtime = stat($file)->mtime;
    #dd $file, $bn, $mtime; # Debug
    $filelist{$bn} = [$file,$mtime]
        unless $filelist{$bn} && $filelist{$bn}[1]>$mtime;
}
#dd \%filelist; # Debug
my @filelist = sort map {$_->[0]} values %filelist;
#dd \@filelist; # Debug

for my $file (@filelist) {
       my $fname = substr($file, rindex($file,"/")+1, length($file)-ri
+ndex($file,"/")-1); #for printing file name in my output
       printf OUT $fname;
    
       open (IN, "<",$file);
       while ($line = <IN>){
             chomp($line);
       if ($line =~/    RULECHECK/){
            @temp = split (/\s+/,$line);
            $start = $temp[2];
            $count = $temp[8];
            if($count > 1000){
                 printf OUT "%-60s %-10s\n",$start,$count;
        }
       }
       }
}
system ("gedit output.txt");
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I am attaching you the full code that I am executing.

This code does not compile, so it can't be the code you're running. If I fix the obvious compilation errors, the code seems to work for me. I'm still confused how you're apparently getting undef values for the filenames - perhaps you could insert the line use Data::Dumper; print Dumper([glob '/user/*/ws/*/BLK_*/*.txt']); before the first for loop and show us the output. Otherwise, please see the three links in my previous post.