The output record separator for the print operator. Ordinarily the print operator simply prints out the comma-separated fields you specify, with no trailing newline or record separator assumed. To get behavior more like awk, set this variable as you would set awk's ORS variable to specify what is printed at the end of the print. (Mnemonic: you set "$\" instead of adding \n at the end of the print. Also, it's just like $/, but it's what you get "back" from Perl.)