Process Memory Top

#!/usr/bin/env bash
# Top processes by RSS memory.
# `comm` may contain whitespace, which would break a column-3 numeric sort.
# Fix: emit `pid rss comm` (numeric BEFORE name), sort on column 2, then
# reformat for the human-readable table.
set -euo pipefail

limit="${1:-5}"

if [[ ! "$limit" =~ ^[0-9]+$ ]] || ((limit < 1)); then
	printf 'Limit must be a positive number.\n' >&2
	exit 1
fi

printf '%-8s %-10s %s\n' "PID" "RSS_KB" "COMMAND"
ps -eo pid=,rss=,comm= \
	| sort -k2 -nr \
	| head -n "$limit" \
	| while read -r pid rss command; do
		printf '%-8s %-10s %s\n' "$pid" "$rss" "$command"
	done