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.\" $FreeBSD: head/lib/libc/gen/getpagesizes.3 267774 2014-06-23 08:25:03Z bapt $
.\"
.Dd September 21, 2009
.Dt GETPAGESIZES 3
.Os
.Sh NAME
.Nm getpagesizes
.Nd "get system page sizes"
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In sys/mman.h
.Ft int
.Fn getpagesizes "size_t pagesize[]" "int nelem"
.Sh DESCRIPTION
The
.Fn getpagesizes
function retrieves page size information from the system.
When it is called with
.Fa pagesize
specified as
.Dv NULL
and
.Fa nelem
specified as 0, it returns the number of distinct page sizes that are
supported by the system.
Otherwise, it assigns up to
.Fa nelem
of the system-supported page sizes to consecutive elements of the
array referenced by
.Fa pagesize .
These page sizes are expressed in bytes.
In this case,
.Fn getpagesizes
returns the number of such page sizes that it assigned to the array.
.Sh RETURN VALUES
If successful, the
.Fn getpagesizes
function returns either the number of page sizes that are supported by
the system or the number of supported page sizes that it assigned to
the array referenced by
.Fa pagesize .
Otherwise, it returns the value\~\-1 and sets
.Va errno
to indicate the error.
.Sh ERRORS
The
.Fn getpagesizes
function will succeed unless:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa pagesize
argument is
.Dv NULL
and the
.Fa nelem
argument is non-zero.
.It Bq Er EINVAL
The
.Fa nelem
argument is less than zero.
.El
.Sh SEE ALSO
.Xr getpagesize 3
.Sh HISTORY
The
.Fn getpagesizes
function first appeared in Solaris 9.
This manual page was written in conjunction with a new but compatible
implementation that was first released in
.Fx 7.3 .
.Sh AUTHORS
This manual page was written by
.An Alan L. Cox Aq Mt alc@cs.rice.edu .