utilities/bin

bin/pow

@@ -0,0 +1,26 @@
+#!/bin/sh
+
+! eq $# 2 && printf "Usage: $0 [base] [exponent]\n" >/dev/stderr && exit 1
+
+! stris int "$1" && printf -- "%b: %b: Not an integer\n" "$0" "$1" >/dev/stderr && exit 1
+! stris int "$2" && printf -- "%b: %b: Not an integer\n" "$0" "$2" >/dev/stderr && exit 1
+
+base=$1
+exponent=$2
+
+result=1
+
+while gt $exponent 0; do
+	result=$(multiply $result $base)
+	exponent=$(-- $exponent)
+done
+
+if ! eq $result $(abs $result) && eq $base $(abs $base); then
+	printf "$0: Result is unexpectedly negative, possible integer overflow\n" >/dev/stderr && exit 1
+elif eq $result 0 && ! eq $base 0; then
+	printf "$0: Result is unexpectedly zero, possible integer overflow\n" >/dev/stderr && exit 1
+else
+	printf "%b\n" $result
+fi
+
+exit 0