#!/usr/bin/perl

use strict;
use warnings;

my $dir = '/etc';
my $prompt = ( -t ) ? 'Enter pattern> ' : '';

print $prompt;
while ( my $pattern = <STDIN>) {
    $pattern =~ s/\s+$//;
    last unless length( $pattern );
    my @matched = eval {
        grep { /$pattern/ } glob "$dir/*";
    };  
    print "Error: $@" if $@; 
    print join( "\n", @matched, $prompt );
}