null.c File Reference

/dev/null (character device 1, 3): reading it gives nothing, the end of the file at once, and what is written to it is thrown away. More...

#include <core/system.h>
#include <dev/dev.h>
#include <fs/posix.h>
#include <aquila/errno.h>
#include <memdev.h>

Go to the source code of this file.

Functions
static ssize_t	nulldev_read (struct devid *dd, off_t offset, struct iobuf *io)
	Reads nothing: /dev/null is always at its end.
static ssize_t	nulldev_write (struct devid *dd, off_t offset, struct iobuf *io)
	Takes all that is written, and throws it away.

Variables
struct dev	nulldev

Detailed Description

/dev/null (character device 1, 3): reading it gives nothing, the end of the file at once, and what is written to it is thrown away.

Definition in file null.c.

Function Documentation

nulldev_read()

ssize_t nulldev_read ( struct devid * dd, off_t offset, struct iobuf * io )

static

Reads nothing: /dev/null is always at its end.

Definition at line 16 of file null.c.

References nulldev_read().

Referenced by nulldev_read().

nulldev_write()

ssize_t nulldev_write ( struct devid * dd, off_t offset, struct iobuf * io )

static

Takes all that is written, and throws it away.

Definition at line 22 of file null.c.

References iobuf_skip(), nulldev_write(), and iobuf::resid.

Referenced by nulldev_write().

Variable Documentation

nulldev

struct dev nulldev

Initial value:

         = {
    .read  = nulldev_read,
    .write = nulldev_write,
 
    .fops  = {
        .open  = posix_file_open,
        .read  = posix_file_read,
        .write = posix_file_write,
        .close = posix_file_close,
 
        .can_read  = __vfs_can_always,
        .can_write = __vfs_can_always,
        .eof       = __vfs_eof_always,
    },
}

Definition at line 13 of file null.c.

Referenced by memdev_mux().