#!/usr/bin/env perl

use strict;
use warnings;
use constant {
    BASE_URL => 'https://www.example.com/reg/',
    LS => '/usr/bin/ls',
    LS_OPTS => [qw{-l -h}],
};

use IPC::System::Simple 'capturex';

die "Usage: $0 dir\n" unless @ARGV;
my $dir = $ARGV[0];
my $base_dir = '/home/ken/tmp/pm_11147164_web_dir_listing/';
my $dir_path = $base_dir . $dir;
die "ERROR: User '$dir' does not exist.\n" unless -e $dir_path && -d _;
chdir $base_dir;
my @listing;

for (capturex(LS, @{+LS_OPTS}, $dir_path)) {
    next if 0 == index $_, 'total';
    /^(.*?\s)(\S+)$/;
    push @listing,
        qq{<li>$1<a href="} . BASE_URL . qq{$dir/$2">$2</a></li>\n};
}

print "<p>User: <strong>$dir</strong></p>\n";

if (@listing) {
    print "<ul>\n";
    print for @listing;
    print "</ul>\n";
}
else {
    print "<p>User '$dir' has no files.</p>\n";
}