To change all uppercase letters to lowercase in vi, you can use the command 
  :%s/.*/\L&/ 

To insert a quote at the beginning of each line
  :%s/^/“/

To insert a quote and comma at the end of each line
  :%s/$/“,/

Find non ASCII Characters
  grep --color='auto' -P  "[\x80-\xFF]"
  grep -P -n "[\x00-\x1F\x7F-\xFF]" input_file
  grep --color='auto' -P -n '[^\x00-\x7F]' 
  grep --color='auto' -P -n "[^[:ascii:]]"
  
  
This will prevent any weird Unicode character showing up in your code.
  :set enc=latin1
  
grep regex operator	Meaning
  ^	Matches the empty string at the beginning of a line; also represents the characters not in the range of a list.
  $	Matches the empty string at the end of a line.
  \b	Matches the empty string at the edge of a word.