title: Bash: shell script if statement using multiple conditions including regex
body: <p>I am currently studying the shell script and having some syntax issue.</p>
  
  <p>what I am tyring is to make the 'if' statement to catch any user-input with alphabet, except the "giveup" line</p>
  
  <p>here is the code that I built:</p>
  
  <pre><code>if [ $usrGuess =~ *[:alpha:]* &amp;&amp; $usrGuess != "giveup" ]
  </code></pre>
  
  <p>once I run the code, it gives out the error message saying that:</p>
  
  <pre><code>[: missing `]'
  </code></pre>
  
  <p>If you guys have any solution to this, I will be happy to hear your advice :)</p>
  
  <p>Thanks!</p>