Use a command to generate a list of source files. The flat file reader reads each file in the list when the session runs. Use a command to generate a file list when the list of source files changes often or you want to generate a file list based on specific conditions. You might want to use a command to generate a file list based on a directory listing.

For example, to use a directory listing as a file list, use the following command:

The command generates a file list from the source file directory listing. When the session runs, the flat file reader reads each file as it reads the file names from the command.

To use the output of a command as a file list, select Command as the Input Type, Command generating file list as the Command Type, and enter a command for the Command property.