I was trying to make a calculator in bash and everything except multiplication works.
My script turns “*” into 0 when I try to multiply.
There is the code:

#!/bin/bash

calculator(){
  if [ $3 = "+" ] ; then
    echo [ $1 $3 $2 ]
  else 
    if [ $3 = "-" ] ; then
      echo [ $1 $3 $2 ]
    else 
      if [ $3 = "/" ] ; then
        echo [ $1 $3 $2 ]
      else
        if [ $3 = "*" ] ; then
          echo [ $1 $3 $2 ]
        else
          echo "$3 error"
        fi        
      fi
    fi
  fi
}

calculator 1 2 *