1 files changed, 72 insertions, 1 deletions
diff --git a/include/system/ctype.h b/include/system/ctype.h
index c771bb69..65e7348f 100644
--- a/include/system/ctype.h
+++ b/include/system/ctype.h
@@ -3,11 +3,82 @@
  * ctype.h - standard ctype functions
  */
 #ifdef SHIM_UNIT_TEST
-#include_next <string.h>
+#include_next <ctype.h>
 #else
 #ifndef _CTYPE_H
 #define _CTYPE_H
 
+#define isprint(c) ((c) >= 0x20 && (c) <= 0x7e)
+
+/* Determines if a particular character is a decimal-digit character */
+static inline __attribute__((__unused__)) int
+isdigit(int c)
+{
+	//
+	// <digit> ::= [0-9]
+	//
+	return (('0' <= (c)) && ((c) <= '9'));
+}
+
+/* Determine if an integer represents character that is a hex digit */
+static inline __attribute__((__unused__)) int
+isxdigit(int c)
+{
+	//
+	// <hexdigit> ::= [0-9] | [a-f] | [A-F]
+	//
+	return ((('0' <= (c)) && ((c) <= '9')) ||
+	        (('a' <= (c)) && ((c) <= 'f')) ||
+	        (('A' <= (c)) && ((c) <= 'F')));
+}
+
+/* Determines if a particular character represents a space character */
+static inline __attribute__((__unused__)) int
+isspace(int c)
+{
+	//
+	// <space> ::= [ ]
+	//
+	return ((c) == ' ');
+}
+
+/* Determine if a particular character is an alphanumeric character */
+static inline __attribute__((__unused__)) int
+isalnum(int c)
+{
+	//
+	// <alnum> ::= [0-9] | [a-z] | [A-Z]
+	//
+	return ((('0' <= (c)) && ((c) <= '9')) ||
+	        (('a' <= (c)) && ((c) <= 'z')) ||
+	        (('A' <= (c)) && ((c) <= 'Z')));
+}
+
+/* Determines if a particular character is in upper case */
+static inline __attribute__((__unused__)) int
+isupper(int c)
+{
+	//
+	// <uppercase letter> := [A-Z]
+	//
+	return (('A' <= (c)) && ((c) <= 'Z'));
+}
+
+/* Convert character to lowercase */
+static inline __attribute__((__unused__)) int
+tolower(int c)
+{
+	if (('A' <= (c)) && ((c) <= 'Z')) {
+		return (c - ('A' - 'a'));
+	}
+	return (c);
+}
+
+static inline __attribute__((__unused__)) int
+toupper(int c)
+{
+	return ((c >= 'a' && c <= 'z') ? c - ('a' - 'A') : c);
+}
 
 #endif /* !_CTYPE_H */
 #endif /* !SHIM_UNIT_TEST */