title: Linux: Illegal option read -a
body: <p>I have found the answer for this question... Just want to provide some information for others, who met this problem too... </p>
  
  <p>In my system, I got this problem because of I used the <code>sh main.sh</code> to process my shell script and ignore the difference between "Bash" and "Shell". </p>
  
  <p>In order to solve this problem, you might try to change the mode into executable, by using <code>chmod +x</code> and using <code>./</code> to execute the program. </p>
  
  <p>Good luck! </p>