DataStage Custom Routine to Get a File Size

Below is a DataStage custom transform routine to get the size of a file. The full path of the file is passed in as a parameter called "Filename".

CMD = "ls -la " : Filename : " | awk '{print $5}'"
CALL DSExecute("UNIX",CMD,Output,SystemReturnCode)
size = Group(Output, @FM, 1)
Ans = If Num(size) Then size Else -1

If the file doesn't exist, -1 is returned.