bool verify_fd_contents(int orig_fd, off_t orig_pos, int copy_fd, off_t copy_pos, size_t length);
bool verify_copy_contents(const char *orig_name, const char *copy_name);
bool verify_copy_sizes(struct stat *orig_sb, struct stat *copy_sb, copyfile_state_t cpf_state,
bool verify_fd_contents(int orig_fd, off_t orig_pos, int copy_fd, off_t copy_pos, size_t length);
bool verify_copy_contents(const char *orig_name, const char *copy_name);
bool verify_copy_sizes(struct stat *orig_sb, struct stat *copy_sb, copyfile_state_t cpf_state,