fcntl.h

Go to the documentation of this file.

/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/********************************************************************************
 * include/fcntl.h
 *
 *   Copyright (C) 2007-2009, 2012 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ********************************************************************************/

#ifndef __INCLUDE_FCNTL_H
#define __INCLUDE_FCNTL_H

/********************************************************************************
 * Included Files
 ********************************************************************************/

#include <tinyara/config.h>

#include <sys/types.h>
#include <stdint.h>

/********************************************************************************
 * Pre-processor Definitions
 ********************************************************************************/

/* open flag settings for open() (and related APIs) */

#define O_RDONLY    (1 << 0)    /* Open for read access (only) */
#define O_RDOK      O_RDONLY    /* Read access is permitted (non-standard) */
#define O_WRONLY    (1 << 1)    /* Open for write access (only) */
#define O_WROK      O_WRONLY    /* Write access is permitted (non-standard) */
#define O_RDWR      (O_RDOK|O_WROK) /* Open for both read & write access */
#define O_CREAT     (1 << 2)    /* Create file/sem/mq object */
#define O_EXCL      (1 << 3)    /* Name must not exist when opened  */
#define O_APPEND    (1 << 4)    /* Keep contents, append to end */
#define O_TRUNC     (1 << 5)    /* Delete contents */
#define O_NONBLOCK  (1 << 6)    /* Don't wait for data */
#define O_NDELAY    O_NONBLOCK  /* Synonym for O_NONBLOCK */
#define O_SYNC      (1 << 7)    /* Synchronize output on write */
#define O_DSYNC     O_SYNC      /* Equivalent to OSYNC in TinyAra */
#define O_BINARY    (1 << 8)    /* Open the file in binary (untranslated) mode. */

/* Unsupported, but required open flags */

#define O_RSYNC     0           /* Synchronize input on read */
#define O_ACCMODE   O_RDWR      /* Mask for access mode */
#define O_NOCTTY    0           /* Required by POSIX */
#define O_TEXT      0           /* Open the file in text (translated) mode. */

/* This is the highest bit number used in the open flags bitset.  Bits above
 * this bit number may be used within TinyAra for other, internal purposes.
 */

#define _O_MAXBIT   8

/* Synonyms historically used as F_SETFL flags (BSD). */

#define FNDELAY     O_NONBLOCK  /* Don't wait for data */
#define FNONBLOCK   O_NONBLOCK  /* Don't wait for data */
#define FAPPEND     O_APPEND    /* Keep contents, append to end */
#define FSYNC       O_SYNC      /* Synchronize output on write */
#define FASYNC      0           /* No counterpart in TinyAra */

/* FFCNTL is all the bits that may be set via fcntl. */

#define FFCNTL      (FNONBLOCK | FNDELAY | FAPPEND | FSYNC | FASYNC)

/* fcntl() commands */

#define F_DUPFD     0           /* Duplicate a file descriptor */
#define F_GETFD     1           /* Read the file descriptor flags */
#define F_GETFL     2           /* Read the file status flags */
#define F_GETLEASE  3           /* Indicates what type of lease is held on fd (linux) */
#define F_GETLK     4           /* Check if we could place a lock */
#define F_GETOWN    5           /* Get the pid receiving  SIGIO and SIGURG signals for fd */
#define F_GETSIG    6           /* Get the signal sent */
#define F_NOTIFY    7           /* Provide notification when directory referred to by fd changes (linux) */
#define F_SETFD     8           /* Set the file descriptor flags to value */
#define F_SETFL     9           /* Set  the  file status flags to the value */
#define F_SETLEASE  10          /* Set or remove file lease (linux) */
#define F_SETLK     11          /* Acquire or release a lock on range of bytes */
#define F_SETLKW    12          /* Like F_SETLK, but wait for lock to become available */
#define F_SETOWN    13          /* Set pid that will receive SIGIO and SIGURG signals for fd */
#define F_SETSIG    14          /* Set the signal to be sent */

/* For posix fcntl() and lockf() */

#define F_RDLCK     0           /* Take out a read lease */
#define F_WRLCK     1           /* Take out a write lease */
#define F_UNLCK     2           /* Remove a lease */

/* close-on-exec flag for F_GETRL and F_SETFL */

#define FD_CLOEXEC  1

/* These are the notifications that can be received from F_NOTIFY (linux) */

#define DN_ACCESS   0           /* A file was accessed */
#define DN_MODIFY   1           /* A file was modified */
#define DN_CREATE   2           /* A file was created */
#define DN_DELETE   3           /* A file was unlinked */
#define DN_RENAME   4           /* A file was renamed */
#define DN_ATTRIB   5           /* Attributes of a file were changed */

/* int creat(const char *path, mode_t mode);
 *
 * is equivalent to open with O_WRONLY|O_CREAT|O_TRUNC.
 */

#define creat(path, mode) open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)

/********************************************************************************
 * Public Type Definitions
 ********************************************************************************/

/* struct flock is the third argument for F_GETLK, F_SETLK and F_SETLKW */

struct flock {
    int16_t l_type;             /* Type of lock: F_RDLCK, F_WRLCK, F_UNLCK */
    int16_t l_whence;           /* How to interpret l_start: SEEK_SET, SEEK_CUR, SEEK_END */
    off_t l_start;              /* Starting offset for lock */
    off_t l_len;                /* Number of bytes to lock */
    pid_t l_pid;                /* PID of process blocking our lock (F_GETLK only) */
};

/********************************************************************************
 * Public Function Prototypes
 ********************************************************************************/

#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif

/********************************************************************************
 * Public Data
 ********************************************************************************/

/* POSIX-like File System Interfaces */
int open(const char *path, int oflag, ...);
int fcntl(int fd, int cmd, ...);

#undef EXTERN
#if defined(__cplusplus)
}
#endif

#endif                          /* __INCLUDE_FCNTL_H */