diff --git a/sys/include/string.h b/sys/include/string.h
new file mode 100644
index 0000000..0320cae
--- /dev/null
+++ b/sys/include/string.h
@@ -0,0 +1,15 @@
+#ifndef STRING_H
+#define STRING_H
+
+#include <types.h>
+
+u32 strlen(const char *str);
+char* strtol(s32 num, char *str, s32 base);
+char* strtoul(u32 num, char *str, s32 base);
+char* strcpy(char *dest, const char *src);
+char* strncpy(char *dest, const char *src, size_t count);
+char* strcat(char *dest, const char *src);
+char* strncat(char *dest, const char *src, size_t count);
+s32 strcmp(const char *lhs, const char *rhs);
+
+#endif
\ No newline at end of file
diff --git a/sys/lib.c b/sys/lib.c
index 1c401d5..fef5f07 100644
--- a/sys/lib.c
+++ b/sys/lib.c
@@ -12,7 +12,7 @@ strlen(const char *str)
 }
 
 char*
-itoa(s32 num, char *str, s32 base)
+strtol(s32 num, char *str, s32 base)
 {
 	s32 i = 0;
 
@@ -33,7 +33,7 @@ itoa(s32 num, char *str, s32 base)
 }
 
 char*
-utoa(u32 num, char *str, s32 base)
+strtoul(u32 num, char *str, s32 base)
 {
 	s32 i = 0;
 
@@ -48,6 +48,80 @@ utoa(u32 num, char *str, s32 base)
 	return str;
 }
 
+char*
+strcpy(char *dest, const char *src)
+{
+	u32 i = 0;
+
+	while (src[i] != NULL) {
+		dest[i] = src[i];
+		i++;
+	}
+
+	return dest;
+}
+
+char*
+strncpy(char *dest, const char *src, size_t count)
+{
+	u32 i = 0;
+
+	while (src[i] != NULL && i < count) {
+		dest[i] = src[i];
+		i++;
+	}
+
+	return dest;
+}
+
+char*
+strcat(char *dest, const char *src)
+{
+	u32 i = 0;
+
+	while (dest[i] != NULL) i++;
+
+	while (src[i] != NULL) {
+		dest[i] = src[i];
+		i++;
+	}
+
+	dest[i] = '\0';
+
+	return dest;
+}
+
+char*
+strncat(char *dest, const char *src, size_t count)
+{
+	u32 i = 0;
+
+	while (dest[i] != NULL) i++;
+
+	while (src[i] != NULL && i < count) {
+		dest[i] = src[i];
+		i++;
+	}
+
+	dest[i] = '\0';
+
+	return dest;
+}
+
+s32
+strcmp(const char *lhs, const char *rhs)
+{
+	u32 i = 0;
+
+	while (lhs[i] != NULL && rhs[i] != NULL) {
+		if (lhs[i] != rhs[i]) {
+			return lhs[i] - rhs[i];
+		}
+	}
+
+	return 0;
+}
+
 s32
 printf(const char *format, ...)
 {
@@ -60,22 +134,22 @@ printf(const char *format, ...)
 			if (format[i + 1] == 'd' || format[i + 1] == 'i') {
 				//integer numbers
 				const s32 num = va_arg(list, s32);
-				const char* str = itoa(num, strbuf, 10);
+				const char* str = strtol(num, strbuf, 10);
 				vga_write(str, sizeof(str), 0x0f);
 			} else if (format[i + 1] == 'o') {
 				//octal numbers
 				const s32 num = va_arg(list, s32);
-				const char *str = itoa(num, strbuf, 8);
+				const char *str = strtol(num, strbuf, 8);
 				vga_write(str, sizeof(str), 0x0f);
 			} else if (format[i + 1] == 'u') {
 				//unsigned integers
 				const u32 num = va_arg(list, u32);
-				const char *str = utoa(num, strbuf, 10);
+				const char *str = strtoul(num, strbuf, 10);
 				vga_write(str, sizeof(str), 0x0f);
 			} else if (format[i + 1] == 'x') {
 				//hexadecimal numbers
 				const u32 num = va_arg(list, u32);
-				const char* str = utoa(num, strbuf, 16);
+				const char* str = strtoul(num, strbuf, 16);
 				vga_write(str, sizeof(str), 0x0f);
 			} else if (format[i + 1] == 's') {
 				//strings
diff --git a/sys/memory.c b/sys/memory.c
index 8003d3b..f4c936a 100644
--- a/sys/memory.c
+++ b/sys/memory.c
@@ -3,15 +3,13 @@
 
 u32 curr = START;
 
-void 
+void
 memory_init(void)
-{ 
+{
 	u32 esp, ebp;
 	ebp = STACK_START;
 	esp = STACK_START;
-
-
-} 
+}
 
 void *malloc(s32 size) {
     u32 addr = curr;