#ifndef _SYS_FILE_H
#define _SYS_FILE_H
#ifdef __cplusplus
extern "C" {
#endif
#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
#define LOCK_SH 1
#define LOCK_EX 2
#define LOCK_NB 4
#define LOCK_UN 8
extern int flock(int, int);
}