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PARAM(3) |
Library Functions Manual |
PARAM(3) |
NAME
param — common parameters
SYNOPSIS
#include <sys/param.h>
size
MAX(size a, size b);
size
MIN(size a, size b);
DESCRIPTION
The
<sys/param.h> header includes some common definitions and macros specific to
NetBSD. The header is perhaps best characterized as a kernel equivalent of
<sys/types.h>. The following list summarizes the provided definitions and macros.
-
First and foremost, the header defines the version of NetBSD. This is defined as
#define __NetBSD_Version__ 599004800 /* 5.99.48 */
The general format is “MMmmrrpp00”, where ‘MM’ and ‘mm’ denote the major and minor version, respectively, ‘rr’ is provided for compatibility, and ‘pp’ defines the patch level.
-
Common utility macros such as MAX() and MIN() as well as more specific macros such as STACK(9), ctod(9), mstohz(9), roundup(9), and setbit(9).
-
Numerous miscellaneous definitions such as limits, constants for the kernel memoryallocators(9), scale factors used by the scheduler, kthread(9) priorities, and many others.
-
Definitions provided for historical and compatibility reasons. Examples range from definitions such as “#define BSD” to old priority levels used in the kernel.
HISTORY
A
<param.h> header appeared already in the Version 4 AT&T UNIX.
