title: Comparing strings for equality in ksh
body: <p>i am testing with the shell script below:</p>
  
  <pre><code>#!/bin/ksh -x
  
  
  instance=`echo $1 | cut -d= -f2`
  if [ $instance == "ALL" ]
  then
  echo "strings matched \n"
  fi
  </code></pre>
  
  <p>It's giving this error in the if condition:</p>
  
  <pre><code>: ==: unknown test operator
  </code></pre>
  
  <p>is <code>==</code> really not the correct syntax to use?
  I am running on the command line as below</p>
  
  <pre><code>test_lsn_2 INSTANCE=ALL
  </code></pre>
  
  <p>Could anybody please suggest a solution.
  Thanks.</p>