Kernel/std: Add strdup()

kernel/include/std/string.h

@@ -16,4 +16,6 @@ char* strstr(char* haystack, const char* needle);
 void* memcpy(void* dest, const void* src, size_t n);
 void* memset(void* dest, int c, size_t n);
 int memcmp(const void* a, const void* b, size_t n);
-void* memmove(void* dest, void* src, size_t n);
+void* memmove(void* dest, void* src, size_t n);
+
+char* strdup(const char* src);

kernel/src/std/string.cpp

@@ -1,4 +1,5 @@
-#include <string.h>
+#include "std/string.h"
+#include "std/stdlib.h"
 
 size_t strlen(const char* __s)
 {
@@ -121,4 +122,12 @@ void* memmove(void* dest, void* src, size_t n)
         for (long i = 0; i < (long)n; i++) { *((char*)dest + i) = *((char*)src + i); }
     }
     return dest;
+}
+
+char* strdup(const char* src)
+{
+    size_t length = strlen(src);
+    char* duplicated = (char*)kmalloc(length + 1);
+    memcpy(duplicated, src, length + 1);
+    return duplicated;
 }