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MAKEDEV(3)                 Linux Programmer's Manual                MAKEDEV(3)

NAME
       makedev, major, minor - manage a device number
SYNOPSIS
       #define _BSD_SOURCE             /* See feature_test_macros(7) */
       #include <sys/types.h>
       dev_t makedev(int maj, int min);
       unsigned int major(dev_t dev);
       unsigned int minor(dev_t dev);
DESCRIPTION
       A device ID consists of two parts: a major ID, identifying the class of
       the device, and a minor ID, identifying a specific instance of a device
       in that class.  A device ID is represented using the type dev_t.
       Given major and minor device IDs, makedev() combines these to produce a
       device ID, returned as the function result.   This  device  ID  can  be
       given to mknod(2), for example.
       The  major()  and  minor() functions perform the converse task: given a
       device ID, they return, respectively, the major and  minor  components.
       These macros can be useful to, for example, decompose the device IDs in
       the structure returned by stat(2).
CONFORMING TO
       The makedev(), major(), and minor()  functions  are  not  specified  in
       POSIX.1, but are present on many other systems.
NOTES
       These  interfaces  are defined as macros.  Since glibc 2.3.3, they have
       been  aliases  for  three  GNU-specific  functions:  gnu_dev_makedev(),
       gnu_dev_major(),  and  gnu_dev_minor().  The latter names are exported,
       but the traditional names are more portable.
SEE ALSO
       mknod(2), stat(2)
COLOPHON
       This page is part of release 3.53 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux                             2012-05-10                        MAKEDEV(3)