Now we're ready for the main loop. First is the repeat while condition. We keep going through the loop until l_offset = 0. How does this happen? Let's take a look at the last record to be deleted. l_filelist will look like:

"ATA_02:Kevin:Temp copy:chill2.mov
	ATA_02:Kevin:Temp copy:cuba_gooding_jr_6.jpg
"

Note that chill2.mov has already been deleted and l_offset points to the "\r\t" between chill2.mov and cuba_gooding_jr_6.jpg. The script strips out the first part of l_offset, leaving:

"ATA_02:Kevin:Temp copy:cuba_gooding_jr_6.jpg
"

Then when it looks for the next "\r\t", there is none so l_offset is set to 0. The file cuba_gooding_jr_6.jpg is deleted and at the next iteration the loop exits.

		repeat while (l_offset > 0)

			-- extract out first element in remaining list
			set l_filelist to extract string l_filelist from (l_offset + 2)

Note here how we strip out the last file deleted, plus the "\r\t" after it. l_offset + 2 points to the next character after "\r\t" and so l_filelist starts immediately with the next file to be deleted.

					-- find offset of next delimiter
			set l_offset to offset of "\r\t" in l_filelist
		
			-- check to see if there is another delimiter
			if (l_offset = 0) then
				-- no other elements
				set l_file to extract string l_filelist Â
				  from 1 to ((length of l_filelist) - 1)
			else
				-- at least one other element
				set l_file to extract string l_filelist Â
				  from 1 to (l_offset - 1)
			end if

This part is a bit important. If l_offset equals 0, then this is the last file to delete, and the last one in l_filelist. So we can just pass the whole string (minus the ending return character) to the delete command. If l_offset is greater than 0, then there will be more files to delete. So we can pass the substring starting from the beginning and ending just before l_offset to the delete command. In either case, l_file ends up with the file specification that must be deleted.

More in the next journal...