rand_t — Generates random text based on /dev/urandom and tr. This is function for ~/.bashrc

random_text.bash

#!/usr/bin/env bash
# shellcheck enable=all

rand_t(){
  local options
  options=$(getopt -n 'rand_t' -o 'hs:w:l:a:x:y:c:m:n:' \
    --long 'help,set:,width:,lines:' -- "${@}")
  eval set -- "${options}"

  local set='A-Za-z0-9_\-'
  local -i width=60
  local -i lines=10

  while [[ -n ${options} ]]; do
    case ${1} in
    -h | --help)
      echo 'Generates random text.' >&2
      echo " -a | -c | -s |   --set <SET> — string of characters. '${set}' is default">&2
      echo " -x | -m | -w | --width <NUM> — number chars in line. ${width} is default">&2
      echo " -y | -n | -l | --lines <NUM> — number lines instead. ${lines} is default">&2
      echo "      -v | -h |  --help — shows this text & example">&2
      echo
      shift 1
      ;;
    -a | -c | -s | --set)
      set="${2}"
      shift 2
      ;;
    -x | -m | -w | --width)
      width="${2}"
      shift 2
      ;;
    -y | -n | -l | --lines)
      lines="${2}"
      shift 2
      ;;
    '--' | '')
      shift 1
      break
      ;;
    *)
      echo "Unknown parameter '${1}'." >&0
      shift 1
      ;;
    esac
  done

  local rest="${*// /}"
  if [[ -n "${rest}" ]]; then
    set="${rest}"
  fi

  < /dev/urandom tr -dc "${set}" \
    | fold --width "${width}" \
    | head --lines "${lines}"  \
    || true
}


randtext(){
  rand_t "${@}"
}