FCNTL.H(7,F)                AIX Technical Reference                FCNTL.H(7,F)



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fcntl.h



PURPOSE

Defines file control options.

SYNOPSIS

#include <fcntl.h>

DESCRIPTION

The fcntl.h header file defines the values that can be specified for the cmd
and arg parameters of the fcntl system call, and for the oflag parameter of the
open system call.

     /* Flag values accessible to open and fcntl */
     /* 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      /* (0x08) append (writes guaranteed */
                                         /*        at the end) */
     #define O_SYNC  0200000    /* Synchronous write */
     #define O_REPLSYNC 0400000 /* Synchronous replicated write */

     /* Flag values accessible only to fcntl */
     #define O_ASYNC  020       /* (0x10) signal pgrp when data ready */
     /* Flag values accessible only to open */

     #define O_DEFERC 00040     /* (0x0020) delay commits of changes */
     #define O_EDELAY 00100     /*Return EAGAIN if block would have occurred*/
     #define O_NONBLOCK (O_NDELAY | O_EDELAY)      /* POSIX compatibility */
     #define O_CREAT  00400     /* (0x0100) open with create (uses third */
                                        /*                open arg) */
     #define O_TRUNC  01000     /* (0x0200) open with truncation */
     #define O_EXCL   02000     /* (0x0400) exclusive open */

     /* fcntl 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 */



Processed November 7, 1990       FCNTL.H(7,F)                                 1

FCNTL.H(7,F)                AIX Technical Reference                FCNTL.H(7,F)



     #define F_GETOWN  9        /* get pgrp */
     #define F_SETOWN 10        /* set pgrp for SIGIO */

     /* file segment locking set data type - information passed to */
     /* system by user */

     struct flock {
          short   l_type;
          short   l_whence;
          long    l_start;
          long    l_len;      /* len = 0 means until end of file */
          unsigned long   l_sysid;
          pid_t   l_pid;
     };

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

FILE

/usr/include/fcntl.h

RELATED INFORMATION

In this book:  "fcntl, flock, lockf" and "open, openx, creat."




























Processed November 7, 1990       FCNTL.H(7,F)                                 2