управлять номером устройства (manage a device number)
Имя (Name)
makedev, major, minor - manage a device number
Синопсис (Synopsis)
#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);
Описание (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).
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────────────────┼───────────────┼─────────┤
│makedev(), major(), minor() │ Thread safety │ MT-Safe │
└──────────────────────────────────────┴───────────────┴─────────┘
Стандарты (Conforming to)
The makedev(), major(), and minor() functions are not specified
in POSIX.1, but are present on many other systems.
Примечание (Note)
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.
The BSDs expose the definitions for these macros via
<sys/types.h>. Depending on the version, glibc also exposes
definitions for these macros from that header file if suitable
feature test macros are defined. However, this behavior was
deprecated in glibc 2.25, and since glibc 2.28, <sys/types.h> no
longer provides these definitions.
Смотри также (See also)
mknod(2), stat(2)
