#!/bin/bash

if ! awk 'END{}' /proc/1/smaps &>/dev/null; then
    echo "Some processes require root privileges. Asking for sudo..."
    exec sudo bash "$0" "$@"
fi

echo " PID     USER       SWAP(MB)  NAME"

for pid in /proc/[0-9]*; do
  [ -r "$pid/smaps" ] || continue
  [ -r "$pid/status" ] || continue

  name=$(awk '/^Name:/ {print $2}' "$pid/status" 2>/dev/null)
  uid=$(awk '/^Uid:/ {print $2}' "$pid/status" 2>/dev/null)
  user=$(getent passwd "$uid" | cut -d: -f1)

  swap_kb=$(awk '/Swap:/ {s+=$2} END {print s+0}' "$pid/smaps" 2>/dev/null)
  swap_kb=${swap_kb:-0}

  if [ "$swap_kb" -gt 0 ] 2>/dev/null; then
    printf "%6s %-10s %9.2f   %s\n" "${pid##*/}" "$user" "$((swap_kb/1024))" "$name"
  fi
done | sort -k3 -nr | head -n 20

awk '/SwapTotal/ {total=$2} /SwapFree/ {free=$2} END {printf "\nTotal system swap used: %.2f MB\n", (total-free)/1024}' /proc/meminfo