validating non form data

[eluser]pickupman[/eluser]
The form validation class can only check if file has been uploaded. I do this same very thing as you are trying. I am uploading price sheets in CSV, and if the data matches, it is inserted/updated in DB. Use the validation class to check file has been uploaded. If the file has been uploaded, use fopen() or load the CI file helper, and use read_file(). I run the file through a loop reading each line. I use a regular expression to check the fields in each row. If it passes the regex test, I added it to the DB.