#!/usr/bin/env bash

# Outputs the seconds since the thing identified by the first argument
# was last modified (not created).

ageof() {
  local path="$1"
  if [[ -z "$path" ]]; then
    echo 'usage: ageof <path>'
    return 1
  fi
  echo $(( $(date +%s) - $(date -r "$path" +%s) ))
}

ageof "$@"