FCNTL(5)                                                 FCNTL(5)



     NAME
          fcntl - file control options

     SYNOPSIS
          #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_NDELAY 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;
                long  l_start;
                long  l_len;      /* if 0 then until EOF */
                short l_sysid;    /* returned with F_GETLK*/
                short 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 */





     Page 1                                        (last mod. 8/20/87)

     FCNTL(5)                                                 FCNTL(5)



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

     ORIGIN
          AT&T V.3


















































     Page 2                                        (last mod. 8/20/87)