A file loop causes a set of steps to be performed one time for each file that has been downloaded or created so far in the task. An unlimited number of steps can appear inside a loop. Any task element, except a schedule, can be inside a loop.
Prerequisite: A file loop must be preceded by at least one source element, or by at least one process that adds to the list of files.
To add a file loop:
Click TASKS, click an Advanced task or create a new one.
If the task does not have a source, add a source.
If this is the first source to be added to the task, you are prompted to add a file loop. Click Yes. The file loop is added immediately after the source in the list of task elements.
If a source already exists, click Step > File Loop. You are prompted for the location of the file loop. At the location, click Insert here.
A For each file... row is added to the list of task elements.
For each element to include in the file loop:
Click Step and select the element. You are prompted for a location.
Click an indented Insert here that is located under the For each file... row that designates the start of the file loop.
Fill out any required fields for the element you are adding. For example, if you are adding a process, select the script and any required parameters.
To reposition any element in the list, click the gear icon and select Move. In the new position in the list, click Move here.
For each file... row is added to the list of task elements. 
and select Move. In the new position in the list, click Move here.