# fieldLengths is specified on the command line with -v
#   "4,3" would mean 2 fields, length 4 and 3.
# rightJustify also with -v.
#   "3,6" would right justify fields 3 and 6.

{
	fieldNum=split(fieldLengths, fieldSpec, ",")
	for (i=1;i<=fieldNum;i++) {
	  gsub(" ", "", $i)

		# build formatStr as %<pad length>s, or %- for left just
		formatStr="%";
		if (!match(rightJustify, "\\<"i"\\>"))
			formatStr=formatStr"-"
		formatStr=formatStr fieldSpec[i]"s"

	  printf(formatStr, $i)
	  if (i != fieldNum)
			printf(",")
		else
			printf("\n")
	}
}