thanks rovf I got the issue by printing $!

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

print "Enter the path where the log file is placed : ";
my $dir =<>;
chomp($dir);
opendir DIR, $dir or die "cannot open dir $dir: $!";
my @files= readdir DIR;
my $len=scalar(@files);
print $len;
print "Enter the path where to save the report";
my $dest_dir = <STDIN>;
chomp($dest_dir);
open(FH1,">$dir./result.txt") if( $len > 0);
foreach my $file (@files){
    if($file=~/\.txt/){
        print "$file\n";
        open(FH,"$dest_dir./$file") or die $!;
        while(my $line= <FH> ){
            print FH1 $line;
        }
        close FH;
    }
}
close FH1;
closedir DIR;
[download]

Any other suggestions or feedbacks on this are welcome. Thanks everyone.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.