messageReadLine

<!-- Initializing the item to hold the message data minus the first line -->
<arc:set attr="restof.data" value="" />
<!-- Calling the messageReadLine operation and setting the output item -->
<arc:call op="messageReadLine" out="result" >
  <!-- Once the operation gets to the first line in the message data, perform a replace -->
  <arc:if exp="[result.line] == 1">
    <arc:set attr="first.line" value="[result.data | replace('Owen','Liu')]" />
    <arc:else>
      <!-- Setting the data for the output message to be the concatenation of the modified first line and the rest of the message data -->
      <arc:set attr="output.data" value="[first.line][restof.data]\n[result.data]" />
    </arc:else>
  </arc:if> 
</arc:call>
<arc:set attr="output.filepath" value="[FilePath]" />
<arc:push item="output" />