MAJOR

Section: Kernel Functions (9)
Updated: $Date:$
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NAME

MAJOR, MINOR, MKDEV - macros to manipulate device major/minor numbers  

SYNOPSIS

#include <linux/fs.h>

#define MAJOR(dev)
#define MINOR(dev)
#define MKDEV(major, minor)

 

DESCRIPTION

The MAJOR and MINOR macros extract from a device id (of type dev_t) the major and minor numbers respectively. It is the combined device number that is found in the struct~file structure.

The MKDEV macro assembles a device number from the supplied major and minor numbers.  

RETURN VALUE

Describe the return values. Enumerate all the distinct values and all the ranges.  

AVAILABILITY

Linux 0.0+

In later kernels (Linux 2.1 and later) there is movement towards using 64bit device numbers. Although it is generally a good idea to not presume to know how device numbers are constructed, it is during this period of transition fundamentally important that you ONLY use these functions to manipulate device numbers.  

SEE ALSO

mknod(1)

Also list some source files for the kernel that implement the functions of the page.  

AUTHOR

Stephen Williams <steve@icarus.com>  

BUGS

These are macros, so parameters may be evaluated multiple times.


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
AVAILABILITY
SEE ALSO
AUTHOR
BUGS