--- a/cos/kernel/snprintf.c	Mon Nov 14 21:31:27 2011 +0100
+++ b/cos/kernel/snprintf.c	Mon Nov 14 21:44:35 2011 +0100
@@ -3,7 +3,20 @@
  */
 #include "kernel.h"
 
-#include "ctype.h"
+/*
+ * NOTE! This ctype does not handle EOF like the standard C
+ * library is required to.
+ */
+
+#define _U	0x01	/* upper */
+#define _L	0x02	/* lower */
+#define _D	0x04	/* digit */
+#define _C	0x08	/* cntrl */
+#define _P	0x10	/* punct */
+#define _S	0x20	/* white space (space/lf/tab) */
+#define _X	0x40	/* hex digit */
+#define _SP	0x80	/* hard space (0x20) */
+
 
 unsigned char _ctype[] = {
 _C,_C,_C,_C,_C,_C,_C,_C,			/* 0-7 */
@@ -31,6 +44,36 @@
 _L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,_L,       /* 224-239 */
 _L,_L,_L,_L,_L,_L,_L,_P,_L,_L,_L,_L,_L,_L,_L,_L};      /* 240-255 */
 
+#define __ismask(x) (_ctype[(int)(unsigned char)(x)])
+
+#define isalnum(c)	((__ismask(c)&(_U|_L|_D)) != 0)
+#define isalpha(c)	((__ismask(c)&(_U|_L)) != 0)
+#define iscntrl(c)	((__ismask(c)&(_C)) != 0)
+#define isdigit(c)	((__ismask(c)&(_D)) != 0)
+#define isgraph(c)	((__ismask(c)&(_P|_U|_L|_D)) != 0)
+#define islower(c)	((__ismask(c)&(_L)) != 0)
+#define isprint(c)	((__ismask(c)&(_P|_U|_L|_D|_SP)) != 0)
+#define ispunct(c)	((__ismask(c)&(_P)) != 0)
+#define isspace(c)	((__ismask(c)&(_S)) != 0)
+#define isupper(c)	((__ismask(c)&(_U)) != 0)
+#define isxdigit(c)	((__ismask(c)&(_D|_X)) != 0)
+
+#define isascii(c) (((unsigned char)(c))<=0x7f)
+#define toascii(c) (((unsigned char)(c))&0x7f)
+
+static inline unsigned char tolower(unsigned char c)
+{
+	if (isupper(c))
+		c -= 'A'-'a';
+	return c;
+}
+
+static inline unsigned char toupper(unsigned char c)
+{
+	if (islower(c))
+		c -= 'a'-'A';
+	return c;
+}
 
 #define MORE_THAN_YOU_WANT	1<<30
 #define MAX_STDOUT_CHARS	255