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/*
* Copyright (c) 2025 Ian Marco Moffett and L5 engineers
* All rights reserved.
*
* 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 of the project 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 _OS_FILEDESC_H_
#define _OS_FILEDESC_H_ 1
#include <sys/seek.h>
#include <sys/types.h>
#include <os/vnode.h>
struct proc;
/*
* Represents a file descriptor
*
* @fdno: File descriptor index
* @off: Current file offset
* @vp: Vnode this fd is linked with
* @mode: File attributes
*/
struct filedesc {
int fdno;
off_t off;
struct vnode *vp;
mode_t mode;
};
/*
* Duplicate a file descriptor
*
* @procp: Process to duplicate from
* @fd: File descriptor to duplicate
*
* Returns the new file descriptor on success, otherwise
* a value of NULL on failure
*/
struct filedesc *fd_dup(struct proc *procp, int fd);
/*
* Initialize a process file descriptor table
* and set up standard streams
*
* @procp: Process of fd table to init
*
* Returns zero on success, less than zero values
* indicate failure.
*/
int fdtab_init(struct proc *procp);
/*
* Open a file
*
* @path: Path to file in which we wish to open
* @mode: Mode of our desired file
*
* Returns the file descriptor on success,
* otherwise a less than zero value on failure.
*/
int fd_open(const char *path, mode_t mode);
/*
* Close a file
*
* @fd: File descriptor to close
*
* Returns zero on success, otherwise a less than
* zero value on failure
*/
int fd_close(int fd);
/*
* Write to a file descriptor
*
* @fd: File descriptor to write to
* @buf: Buffer to write
* @count: Buffer byte count
*
* Returns the number of bytes written on success, otherwise
* a less than zero value on error.
*/
ssize_t write(int fd, const void *buf, size_t count);
/*
* Read a file descriptor
*
* @fd: File descriptor to read from
* @buf: Buffer to read into
* @count: Number of bytes to read
*
* Returns the number of bytes read on success, otherwise a less
* than zero value on error.
*/
ssize_t read(int fd, void *buf, size_t count);
/*
* Reposition the file offset of a file
*
* @fd: File descriptor to reposition
* @offset: Offset to move `fd' to
* @whence: How it should be repositioned
*/
off_t lseek(int fd, off_t offset, int whence);
#endif /* !_OS_FILEDESC_H_ */
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