title: How to replace an UNKNOWN Word after a specific word with sed?
body: <p>I have a file named <code>const.lib</code> which includes parameters and passwords.
  My file looks as follows and I want my DB-admin to update the password (which I don't know) assigned to the parameter <code>vORAPASS</code> without opening an editing manually my file. </p>
  
  <pre><code>if [[ $ZONE = "developement" ]]
   then
  
   declare -rx vLEVEL=DEV
  
      declare -rx vORACONSTR=run.dev.zone
      declare -rx vSORAUSER=master
      declare -rx vORAPASS=KNOWNPASSWD
      declare -rx vORASCHEME=master
          ...
  
  
  elif [[ $ZONE = "test" ]]
   then
  
   declare -rx vLEVEL=TINT
  
      declare -rx vORACONSTR=run.tint.zone
      declare -rx vSORAUSER=master
      declare -rx vORAPASS=UNKNOWNPASSWD
      declare -rx vORASCHEME=master
  
  
  elif [[ $ZONE = "production" ]]
   then
  
    declare -rx vLEVEL=PROD
  
      declare -rx vORACONSTR=run.prod.zone
      declare -rx vSORAUSER=master
      declare -rx vORAPASS=UNKNOWNPASSWD
      declare -rx vORASCHEME=master
         ...
  
  fi
  </code></pre>
  
  <p>How can I use sed for this to change the 3rd occurance only?
  THX in advance :)</p>