1 files changed, 42 insertions, 1 deletions
diff --git a/src/stdlib.c b/src/stdlib.c
index 9a9425f..46bdce8 100644
--- a/src/stdlib.c
+++ b/src/stdlib.c
@@ -1,7 +1,48 @@
+#include <stdbool.h>
+#include "string.h"
 #include "stdlib.h"
+#include "stddef.h"
 
+static void strreverse( char *s )
+{
+	char *end = s + strlen( s ) - 1;
+	
+	while( s < end ) {
+		// XOR swap;
+		*s ^= *end;
+		*end ^= *s;
+		*s ^= *end;
+		s++;
+		end--;
+	}
+}
+    
 char *itoa( int v, char *s, int base )
 {
-	//~ *s = '\0';
+	static char digit[] = "0123456789ABCDEF";
+	bool sign = false;
+	char *p = s;
+	
+	if( base < 2 || base > 16 ) {
+		return NULL;
+	}
+	
+	if( v < 0 ) {
+		v = -v;
+		sign = true;
+	} 
+	
+	do {
+		*p++ = digit[v % base];
+	} while( ( v /= base ) > 0 );
+
+	if( sign ) {
+		*p++ = '-';
+	}
+	*p = '\0';
+	
+	strreverse( s );
+	
 	return s;
 }
+