major3
Manage a device number
Part of makedev(3).
Usage
#include <sys/sysmacros.h>
dev_t makedev(unsigned int maj, unsigned int min);
unsigned int major(dev_t dev); unsigned int minor(dev_t dev);
Library
Standard C library (libc, -lc)
Overview
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).
Attributes
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| makedev(), major(), minor() | Thread safety | MT-Safe |
Versions
The BSDs expose the definitions for these macros via <sys/types.h>.
Releases
9 releases since Debian 6.0 (Squeeze); the text changed 8 times.