+/**
+ * Check if character is a hexadecimal digit
+ *
+ * @v character ASCII character
+ * @ret is_xdigit Character is a hexadecimal digit
+ */
+static inline int isxdigit ( int character ) {
+
+ return ( ( ( character >= '0' ) && ( character <= '9' ) ) ||
+ ( ( character >= 'A' ) && ( character <= 'F' ) ) ||
+ ( ( character >= 'a' ) && ( character <= 'f' ) ) );
+}
+
+/**
+ * Check if character is an upper-case letter
+ *
+ * @v character ASCII character
+ * @ret is_upper Character is an upper-case letter
+ */
+static inline int isupper ( int character ) {
+
+ return ( ( character >= 'A' ) && ( character <= 'Z' ) );
+}
+
+/**
+ * Check if character is a lower-case letter
+ *
+ * @v character ASCII character
+ * @ret is_lower Character is a lower-case letter
+ */
+static inline int islower ( int character ) {
+
+ return ( ( character >= 'a' ) && ( character <= 'z' ) );
+}
+
+/**
+ * Check if character is alphabetic
+ *
+ * @v character ASCII character
+ * @ret is_alpha Character is alphabetic
+ */
+static inline int isalpha ( int character ) {
+
+ return ( isupper ( character ) || islower ( character ) );
+}
+
+/**
+ * Check if character is alphanumeric
+ *
+ * @v character ASCII character
+ * @ret is_alnum Character is alphanumeric
+ */
+static inline int isalnum ( int character ) {
+
+ return ( isalpha ( character ) || isdigit ( character ) );
+}
+
+/**
+ * Check if character is printable
+ *
+ * @v character ASCII character
+ * @ret is_print Character is printable
+ */
+static inline int isprint ( int character ) {
+
+ return ( ( character >= ' ' ) && ( character <= '~' ) );
+}
+
+/**
+ * Convert character to lower case
+ *
+ * @v character Character
+ * @v character Lower-case character
+ */
+static inline int tolower ( int character ) {
+
+ return ( isupper ( character ) ?
+ ( character - 'A' + 'a' ) : character );
+}
+
+/**
+ * Convert character to upper case
+ *
+ * @v character Character
+ * @v character Upper-case character
+ */
+static inline int toupper ( int character ) {
+
+ return ( islower ( character ) ?
+ ( character - 'a' + 'A' ) : character );