ssize_t para_write_all(int fd, const void *buf, size_t size);
int para_lseek(int fd, off_t *offset, int whence);
int para_write_file(const char *filename, const void *buf, size_t size);
ssize_t para_write_all(int fd, const void *buf, size_t size);
int para_lseek(int fd, off_t *offset, int whence);
int para_write_file(const char *filename, const void *buf, size_t size);