1 /* The <fcntl.h> header is needed by the open() and fcntl() system calls,
2 * which have a variety of parameters and flags. They are described here.
3 * The formats of the calls to each of these are:
5 * open(path, oflag [,mode]) open a file
6 * fcntl(fd, cmd [,arg]) get or set file attributes
13 /* These values are used for cmd in fcntl(). POSIX Table 6-1. */
14 #define F_DUPFD 0 /* duplicate file descriptor */
15 #define F_GETFD 1 /* get file descriptor flags */
16 #define F_SETFD 2 /* set file descriptor flags */
17 #define F_GETFL 3 /* get file status flags */
18 #define F_SETFL 4 /* set file status flags */
19 #define F_GETLK 5 /* get record locking information */
20 #define F_SETLK 6 /* set record locking information */
21 #define F_SETLKW 7 /* set record locking info; wait if blocked */
23 /* File descriptor flags used for fcntl(). POSIX Table 6-2. */
24 #define FD_CLOEXEC 1 /* close on exec flag for third arg of fcntl */
26 /* L_type values for record locking with fcntl(). POSIX Table 6-3. */
27 #define F_RDLCK 0 /* shared or read lock */
28 #define F_WRLCK 1 /* exclusive or write lock */
29 #define F_UNLCK 2 /* unlock */
31 /* Oflag values for open(). POSIX Table 6-4. */
32 #define O_CREAT 00100 /* creat file if it doesn't exist */
33 #define O_EXCL 00200 /* exclusive use flag */
34 #define O_NOCTTY 00400 /* do not assign a controlling terminal */
35 #define O_TRUNC 01000 /* truncate flag */
37 /* File status flags for open() and fcntl(). POSIX Table 6-5. */
38 #define O_APPEND 02000 /* set append mode */
39 #define O_NONBLOCK 04000 /* no delay */
41 /* File access modes for open() and fcntl(). POSIX Table 6-6. */
42 #define O_RDONLY 0 /* open(name, O_RDONLY) opens read only */
43 #define O_WRONLY 1 /* open(name, O_WRONLY) opens write only */
44 #define O_RDWR 2 /* open(name, O_RDWR) opens read/write */
46 /* Mask for use with file access modes. POSIX Table 6-7. */
47 #define O_ACCMODE 03 /* mask for file access modes */
49 /* Struct used for locking. POSIX Table 6-8. */
51 short l_type; /* type: F_RDLCK, F_WRLCK, or F_UNLCK */
52 short l_whence; /* flag for starting offset */
53 off_t l_start; /* relative offset in bytes */
54 off_t l_len; /* size; if 0, then until EOF */
55 pid_t l_pid; /* process id of the locks' owner */
59 /* Function Prototypes. */
64 _PROTOTYPE( int creat, (const char *_path, Mode_t _mode) );
65 _PROTOTYPE( int fcntl, (int _filedes, int _cmd, ...) );
66 _PROTOTYPE( int open, (const char *_path, int _oflag, ...) );