Why is my Bash script adding to the beginning of files?

Question

I\'ve written a script that cleans up .csv files, removing some bad commas and bad quotes (bad, means they break an in house program we use to transform these files) using sed:

Answer 1

U+FEFF is the code point for a byte order mark. Your files most likely contain data saved in UTF-16 and the BOM has been corrupted by your 'cleaning process' which is most likely expecting ASCII. It's probably not a good idea to remove the BOM, but instead to fix your scripts to not corrupt it in the first place.