Copyright (c) 1990, 1991, 1993
The Regents of the University of California. All rights reserved.
This code is derived from software contributed to Berkeley by
Chris Torek.
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. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
@(#)bzero.3 8.1 (Berkeley) 6/4/93
$FreeBSD$
.Dd August 24, 2015 .Dt BZERO 3 .Os .Sh NAME .Nm bzero , .Nm explicit_bzero .Nd write zeroes to a byte string .Sh LIBRARY .Lb libc .Sh SYNOPSIS n strings.h .Ft void .Fn bzero "void *b" "size_t len" .Ft void .Fn explicit_bzero "void *b" "size_t len" .Sh DESCRIPTION The .Fn bzero function writes .Fa len zero bytes to the string .Fa b . If .Fa len is zero, .Fn bzero does nothing.
The Regents of the University of California. All rights reserved.
This code is derived from software contributed to Berkeley by
Chris Torek.
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. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
@(#)bzero.3 8.1 (Berkeley) 6/4/93
$FreeBSD$
.Dd August 24, 2015 .Dt BZERO 3 .Os .Sh NAME .Nm bzero , .Nm explicit_bzero .Nd write zeroes to a byte string .Sh LIBRARY .Lb libc .Sh SYNOPSIS n strings.h .Ft void .Fn bzero "void *b" "size_t len" .Ft void .Fn explicit_bzero "void *b" "size_t len" .Sh DESCRIPTION The .Fn bzero function writes .Fa len zero bytes to the string .Fa b . If .Fa len is zero, .Fn bzero does nothing.
p The .Fn explicit_bzero variant behaves the same, but will not be removed by a compiler's dead store optimization pass, making it useful for clearing sensitive memory such as a password. .Sh SEE ALSO .Xr memset 3 , .Xr swab 3 .Sh HISTORY A .Fn bzero function appeared in x 4.3 . Its prototype existed previously in n string.h before it was moved to n strings.h for .St -p1003.1-2001 compliance.
p The .Fn explicit_bzero function first appeared in .Ox 5.5 and .Fx 11.0 .
p .St -p1003.1-2008 removes the specification of .Fn bzero and it is marked as LEGACY in .St -p1003.1-2004 . For portability with other systems new programs should use .Xr memset 3 .