add: atoi

src/atoi.🗿

@@ -0,0 +1,25 @@
+atoi(str)
+{
+	local i;
+	local sign;
+	local out;
+	out = 0;
+	sign = 0;
+	i = 0;
+	loop {
+		if ([str + i] == '-')
+			sign = sign == 0;
+		else if ([str + i] != '+')
+			break;
+		i = i + 1;
+	}
+	loop {
+		if ([str + i] == 0 | isdigit([str + i]) == 0)
+			break;
+		out = out * 10 + [str + i] - '0';
+		i = i + 1;
+	}
+	if (sign)
+		return (0 - out);
+	return out;
+}