#!/usr/bin/perl

use strict;
use warnings;

# This script uses the 'ss' command to list network connections and the
# processes and users that own them. It relies on parsing human-readable
# output, which can be fragile if the output format of 'ss' changes.

# Command to execute. Flags are:
# -t: TCP, -u: UDP, -p: processes, -a: all, -n: numeric, -e: extended
my $ss_cmd = 'ss -tupane';

# A hash to store our results, structured as:
# $connections->{program_name}->{pid}->{user} = "username"
# $connections->{program_name}->{pid}->{conns} = ["connection_string", ...]
my %connections;

# Execute the command and open a pipe to its output.
# Die with an error message if the command cannot be run.
open(my $ss_pipe, '-|', $ss_cmd)
  or die "Cannot execute '$ss_cmd': $!";

# Skip the header line of the ss output.
<$ss_pipe>;

while (my $line = <$ss_pipe>) {
    chomp $line;

    # The regex is the most complex part. It now also captures the UID.
    # It captures:
    # 1: Protocol (tcp or udp)
    # 2: State (e.g., ESTAB, LISTEN)
    # 3: Local Address:Port
    # 4: Peer Address:Port
    # 5: Process Name
    # 6: PID
    # 7: UID
    if ($line =~ /^(udp|tcp)\s+([A-Z-]+)\s+\S+\s+\S+\s+([\d.:*]+\[?[\d.:]*\]?:\S+)\s+([\d.:*]+\[?[\d.:]*\]?:\S+)\s+users:\(\("([^"]+)",pid=(\d+)[^)]*\)\).*\buid:(\d+)/) {
        my ($proto, $state, $local, $peer, $pname, $pid, $uid) = ($1, $2, $3, $4, $5, $6, $7);

        # Look up the username from the UID.
        # If the UID is not found, default to "uid:<uid_number>".
        my $user = getpwuid($uid);
        $user //= "uid:$uid";

        # Format the connection string for display.
        my $conn_string = sprintf(
            "  %-5s %-12s %-22s -> %-22s",
            $proto, $state, $local, $peer
        );

        # Store the user info (only needs to be stored once per process).
        $connections{$pname}{$pid}{'user'} = $user;
        # Store the connection string.
        push @{ $connections{$pname}{$pid}{'conns'} }, $conn_string;
    }
}

close $ss_pipe;

# Print the results in an organized fashion.
if (!%connections) {
    print "No active connections with process information found.\n";
    exit;
}

# Sort by program name for consistent output.
foreach my $pname (sort keys %connections) {
    foreach my $pid (sort { $a <=> $b } keys %{ $connections{$pname} }) {
        # Retrieve the stored user and connection list.
        my $user = $connections{$pname}{$pid}{'user'};
        my $conns_ref = $connections{$pname}{$pid}{'conns'};

        # Print the header with Program, PID, and the new User info.
        print "Program: $pname (PID: $pid, User: $user)\n";

        foreach my $conn (@$conns_ref) {
            print "$conn\n";
        }
        print "\n";
    }
}

conky.config = {
    own_window = true,
    own_window_type = 'normal',
    own_window_transparent = true,
    own_window_argb_visual = true,
    own_window_hints = 'undecorated,skip_taskbar,skip_pager,below',
    double_buffer = true,
    use_spacer = 'right',

    double_buffer = true,
	no_buffers = true,
	text_buffer_size = 4096,

	use_xft = true,

    alignment = 'bottom_left',
    gap_x = 20,
    gap_y = 10,
    update_interval = 5,
    minimum_width = 600,
    maximum_width = 1200,

    stippled_borders = 3,
    border_width = 1,
    default_color = '888888',
    draw_outline = no,
    draw_borders = yes,
    font = 'monospace:size=12',
    uppercase = no,
    draw_shades = yes,
}

conky.text = [[
${color lightblue}Connections by programs:${color}
${color white}${execi 10 /usr/bin/perl /usr/local/bin/netinfo.pl}
${hr 2}
]];