int os_atoi(const char* nptr);
void* os_calloc(size_t nmemb, size_t size);
char* os_dirname(char* path);
-int os_dlclose(void* handle);
char* os_dlerror(void);
-void* os_dlopen(const char* filename, int flag);
void* os_dlsym(void* handle, const char* symbol);
int os_fclose(FILE* fp);
FILE* os_fopen(const char* path, const char* mode);