.\"-
.\" Copyright (c) 2015 Universitetet i Oslo
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. The name of the author may not be used to endorse or promote
.\"    products derived from this software without specific prior written
.\"    permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd December 15, 2015
.Dt cryb_memset_s 3
.Os
.Sh NAME
.Nm cryb_memset_s
.Nd safely fill a buffer
.Sh LIBRARY
.Lb libcryb-core
.Sh SYNOPSIS
.In cryb/memset_s.h
.Ft void *
.Fn cryb_memset_s "void *d" "size_t dsz" "int ch" "size_t n"
.Sh DESCRIPTION
The
.Nm cryb_memset_s
function overwrites the first
.Va n
bytes of the buffer pointed to by
.Va d ,
of size
.Va dsz ,
with copies of the least-significant byte of
.Va ch .
If
.Va n
is greater than
.Va dsz ,
only
.Va dsz
bytes are overwritten, and an error is returned.
.Sh RETURN VALUES
The
.Nm
function returns zero if successful and a non-zero error code if an
error occurred.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Va d
argument was
.Dv NULL .
.It Bq Er ERANGE
Either or both of the
.Va dsz
and
.Va n
arguments were greater than
.Dv SIZE_MAX .
.It Bq Er EOVERFLOW
The
.Va n
argument was greater than the
.Va dsz
argument.
.El
.Sh IMPLEMENTATION NOTES
If the
.Dv HAVE_MEMSET_S
preprocessor macro is defined to 0 or undefined, the
.In cryb/memset_s.h
header provides a
.Fn memset_s
macro as an alias to
.Fn cryb_memset_s .
.Pp
The argument and return types for
.Nm
differ from those of its C11 equivalent, as it is expected to be used
in environments in which
.Vt rsize_t
and
.Dv RSIZE_MAX
are not defined.
.Sh SEE ALSO
.Xr cryb_memcpy_s 3 ,
.Xr memset 3
.Sh AUTHORS
The
.Fn cryb_memset_s
function and this manual page were written for the University of Oslo
by
.An Dag-Erling Sm\(/orgrav Aq Mt d.e.smorgrav@usit.uio.no .