langs a-z

Task/Averages-Arithmetic-mean/UNIX-Shell/averages-arithmetic-mean.sh

@@ -0,0 +1,24 @@
+mean() {
+	if expr $# >/dev/null; then
+		(count=0
+		 sum=0
+		 while expr $# \> 0 >/dev/null; do
+			sum=`expr $sum + "$1"`
+			result=$?
+			expr $result \> 1 >/dev/null && exit $result
+
+			count=`expr $count + 1`
+			shift
+		 done
+		 expr $sum / $count)
+	else
+		echo 0
+	fi
+}
+
+printf "test 1: "; mean				# 0
+printf "test 2: "; mean 300			# 300
+printf "test 3: "; mean 300 100 400		# 266
+printf "test 4: "; mean -400 400 -1300 200	# -275
+printf "test 5: "; mean -			# expr: syntax error
+printf "test 6: "; mean 1 2 A 3			# expr: non-numeric argument