linux内核中的fcntl.h文件操作中的打开文件模式的宏定义

#ifndef _ALPHA_FCNTL_H#define _ALPHA_FCNTL_H/* open/fcntl - O_SYNC is only implemented on blocks devices and on files   located on an ext2 file system */#define O_ACCMODE     0003   //#define O_RDONLY        00   //只读打开#define O_WRONLY        01   //只写打开#define O_RDWR          02   //读写打开#define O_CREAT      01000  /* not fcntl *///文件不存在则创建#define O_TRUNC      02000  /* not fcntl */若文件存在并且写方式打开成功，则将文件截短为0#define O_EXCL       04000  //测试文件是否存在，不存在则创建#define O_NOCTTY    010000  //如果pathname指向一个终端设备，则不会把此设备终端分配给作为当前进程的控制终端#define O_NONBLOCK   00004   //如果指定文件为命名管道、快设备、或者字符设备，则将此设备设为阻塞#define O_APPEND     00010   //每次写文件都把数据加到文件结尾#define O_NDELAY    O_NONBLOCK  //对文件使用非阻塞方式#define O_SYNC      040000#define FASYNC      020000  /* fcntl, for BSD compatibility */#define O_DIRECTORY 0100000 /* must be a directory */#define O_NOFOLLOW  0200000 /* don't follow links */#define O_LARGEFILE 0400000 /* will be set by the kernel on every open */#define O_DIRECT    02000000 /* direct disk access - should check with OSF/1 */#define O_NOATIME   04000000#define F_DUPFD     0   /* dup */#define F_GETFD     1   /* get close_on_exec */#define F_SETFD     2   /* set/clear close_on_exec */#define F_GETFL     3   /* get file->f_flags */#define F_SETFL     4       /* set file->f_flags */#define F_GETLK     7#define F_SETLK     8#define F_SETLKW    9#define F_SETOWN    5   /*  for sockets. */#define F_GETOWN    6   /*  for sockets. */#define F_SETSIG    10  /*  for sockets. */#define F_GETSIG    11  /*  for sockets. *//* for F_[GET|SET]FL */#define FD_CLOEXEC  1   /* actually anything with low bit set goes *//* for posix fcntl() and lockf() */#define F_RDLCK     1#define F_WRLCK     2#define F_UNLCK     8/* for old implementation of bsd flock () */#define F_EXLCK     16  /* or 3 */#define F_SHLCK     32  /* or 4 */#define F_INPROGRESS    64/* operations for bsd flock(), also used by the kernel implementation */#define LOCK_SH     1   /* shared lock */#define LOCK_EX     2   /* exclusive lock */#define LOCK_NB     4   /* or'd with one of the above to prevent                   blocking */#define LOCK_UN     8   /* remove lock */#define LOCK_MAND      32      /* This is a mandatory flock */#define LOCK_READ      64      /* ... Which allows concurrent read operations */#define LOCK_WRITE     128     /* ... Which allows concurrent write operations */#define LOCK_RW        192     /* ... Which allows concurrent read & write ops */                                                   struct flock {    short l_type;    short l_whence;    __kernel_off_t l_start;    __kernel_off_t l_len;    __kernel_pid_t l_pid;};#define F_LINUX_SPECIFIC_BASE  1024#endif