Fixing up problematic files
The problem: If you use Excel or various other programs to generate a CSV file, you may end up with the wrong characters indicating that each line has ended. This is not obvious in TextWrangler. Here is how to detect if you have the problem: unix commands will return information about the last line only. For example,
The solution: Run a python program that will read your file, change each problematic end-of-line character into the correct one, and then write out the correct version (in the same file).
Verifying it has been fixed: Rerun your unix commands - they should show all the lines now.