function abs(x) {

	return (x+0 >= 0) ? x : -x

}

function check(x,what,  f,res) {

	for (f in formats) {

		res = sprintf(f,x)

		if (formats[f] == "non-decimal") {

			if ((x >= 0) && (res !~ /e+/)) {

				if (abs(strtonum(res)-x) > 1e-5*abs(x))

				       printf "(sprintf(%s,%s) = %s)-%g = %g\n",

					      f,what,res,x,strtonum(res)-x

			}

		}

		else if (abs(res-x) > 1e-5*abs(x))

			printf "(sprintf(%s,%s) = %s)-%g = %g\n",

			       f,what,res,x,res-x

	}

}

function check_cons(fmt,base,rot,mexp,  i,j,dig,res,s) {

	# first off, check that zero formats properly

	if ((s = sprintf(fmt,0)) != "0")

		printf "(sprintf(%s,0) = %s) != 0\n",fmt,s

	res = "1"

	dig = 1

	j = 0

	for (i = 0; i <= mexp; i++) {

		s = sprintf(fmt,base^i)

		if (s ~ /e+/)

			return

		if (s != res)

			printf "(sprintf(%s,%d^%d) = %s) != %s\n",

			       fmt,base,i,s,res

		if (++j == rot) {

			dig = 1

			res = ("10"substr(res,2))

			j = 0

		}

		else {

			dig *= 2

			res = (dig substr(res,2))

		}

	}

}

BEGIN {

	# this doesn't necessarily have to be exact since we're checking

	# magnitude rather than precision

	if (!HUGEVAL) HUGEVAL = 1.7976931348623157e+308

	formats["%s"] = ""

	formats["%d"] = ""

	formats["%.0f"] = ""

	formats["0%o"] = "non-decimal"

	formats["0x%x"] = "non-decimal"

	check(0,"0")

	limit = HUGEVAL / 10

	value = 1

	for (i = 0; ; i++) {

		check(10^i,"10^"i)

		check(-10^i,"-10^"i)

		#[probably should test value against 10^i here]

		if (value >= limit) break

		value *= 10

	}

	limit = HUGEVAL / 2

	value = 1

	for (i = 0; ; i++) {

		check(2^i,"2^"i)

		check(-2^i,"-2^"i)

		#[probably should test value against 2^i here]

		if (value >= limit) break

		value *= 2

	}

	check_cons("%d",10,1,9)

	check_cons("%x",2,4,31)

	check_cons("%o",2,3,31)

	# make sure basic %d and %x are working properly

	printf "%d %d %x\n",3.7,-3.7,23.7

	# check another problem in gawk 3.1.5: precision over 30 crashes

	printf "%.55d\n",1

}