Use the File exists job entry to verify that a specified file exists on the server on which Pentaho Data Integration is running. You must provide the file name. Pentaho Data Integration returns a True or False value depending on whether or not the file exists.
The File Exists job entry can be an easy integration point with other systems. For example, suppose you have a three-part data warehouse load process. The first part runs in PERL. You have batch scripts that accesses data from a remote location, performs first-level row processing, and outputs the data to a specified directory. You do not want to start the job until this is done, so you put the job on a scheduler. As soon as the task is complete, the file is placed in a well-known location so that the "file exists." That is the signal that launches the job for final processing.