$,      The output field separator for the  print  operator.
             Ordinarily  the print operator simply prints out the
             comma separated fields you specify.  In order to get
             behavior  more  like  awk,  set this variable as you
             would set awk's OFS  variable  to  specify  what  is
             printed  between fields.  (Mnemonic: what is printed
             when there is a , in your print statement.)