# addcomma - put commas in numbers

#   input:  a number per line

#   output: the input number followed by

#      the number with commas and two decimal places 

{ printf("%-12s %20s\n", $0, addcomma($0)) }

function addcomma(x,   num) {

 	if (x < 0)

 	    return "-" addcomma(-x)

 	num = sprintf("%.2f", x)   # num is dddddd.dd

 	while (num ~ /[0-9][0-9][0-9][0-9]/)

 	    sub(/[0-9][0-9][0-9][,.]/, ",&", num)

 	return num

}