int para_fchdir(int fd);
int mmap_full_file(const char *filename, int open_mode, void **map,
size_t *size, int *fd_ptr);
-int para_munmap(void *start, size_t length);
+int osl_munmap(void *start, size_t length);
+int write_all(int fd, const char *buf, size_t *len);
+int write_file(const char *filename, const void *buf, size_t size);
/**
* A wrapper for mkdir(2).