fcntl(5P)        INTERACTIVE UNIX System (POSIX)        fcntl(5P)



          NAME
               fcntl - file control options

          SYNOPSIS
               #include <sys/types.h>
               #include <fcntl.h>

          DESCRIPTION
               The fcntl(2) function provides for control over open files.
               This include file describes requests and arguments to fcntl
               and open(2).

               /* Flag values accessible to open(2) and fcntl(2) */
               /*  (The first three can only be set by open) */
               #define O_RDONLY         0
               #define O_WRONLY         1
               #define O_RDWR           2
               #define O_NONBLOCK      04    /* Non-blocking I/O */
               #define O_APPEND       010    /* append (writes guaranteed at the end) */
               #define O_SYNC         020    /* synchronous write option */

               /* Flag values accessible only to open(2) */
               #define O_CREAT      00400    /* open with file create (uses third open arg)*/
               #define O_TRUNC      01000    /* open with truncation */
               #define O_EXCL       02000    /* exclusive open */

               /* fcntl(2) requests */
               #define F_DUPFD          0    /* Duplicate fildes */
               #define F_GETFD          1    /* Get fildes flags */
               #define F_SETFD          2    /* Set fildes flags */
               #define F_GETFL          3    /* Get file flags */
               #define F_SETFL          4    /* Set file flags */
               #define F_GETLK          5    /* Get file lock */
               #define F_SETLK          6    /* Set file lock */
               #define F_SETLKW         7    /* Set file lock and wait */
               #define F_CHKFL          8    /* Check legality of file flag changes */

               /* file segment locking control structure */
               struct flock {
                   short l_type;
                   short l_whence;
                   off_t l_start;
                   off_t l_len;      /* if 0 then until EOF */
                   short l_sysid;    /* returned with F_GETLK*/
                   pid_t l_pid;      /* returned with F_GETLK*/
               }

               /* file segment locking types */
               #define F_RDLCK 01   /* Read lock */
               #define F_WRLCK 02   /* Write lock */
               #define F_UNLCK 03   /* Remove locks */




          Rev. 1.1                                                   Page 1

          fcntl(5P)        INTERACTIVE UNIX System (POSIX)        fcntl(5P)



          SEE ALSO
               fcntl(2), open(2P).





















































          Rev. 1.1                                                   Page 2