title: Bash parameter verification using regex
body: <p>I don't how to use regex properly in bash, i got an error trying to do in this way, what is wrong in that regex verification?</p>
  
  <pre><code>#!/bin/bash
  
  if [ ! $# -eq 1 ]; then
          echo "Error: wrong parameters"
  else
          if [ $1 =~ "[a-z]" ]; then
                  echo "$1: word"
          elif [ $1 =~ "[0-9]" ]; then
                  echo "$1: number"
          else
                  echo "$1: invalid parameter"
          fi
  fi
  </code></pre>