158f0484fSRodney W. Grimes.\" Copyright (c) 1990, 1991, 1993 258f0484fSRodney W. Grimes.\" The Regents of the University of California. All rights reserved. 358f0484fSRodney W. Grimes.\" 458f0484fSRodney W. Grimes.\" This code is derived from software contributed to Berkeley by 558f0484fSRodney W. Grimes.\" Chris Torek. 658f0484fSRodney W. Grimes.\" 758f0484fSRodney W. Grimes.\" Redistribution and use in source and binary forms, with or without 858f0484fSRodney W. Grimes.\" modification, are permitted provided that the following conditions 958f0484fSRodney W. Grimes.\" are met: 1058f0484fSRodney W. Grimes.\" 1. Redistributions of source code must retain the above copyright 1158f0484fSRodney W. Grimes.\" notice, this list of conditions and the following disclaimer. 1258f0484fSRodney W. Grimes.\" 2. Redistributions in binary form must reproduce the above copyright 1358f0484fSRodney W. Grimes.\" notice, this list of conditions and the following disclaimer in the 1458f0484fSRodney W. Grimes.\" documentation and/or other materials provided with the distribution. 153fb3b97cSEd Maste.\" 3. Neither the name of the University nor the names of its contributors 1658f0484fSRodney W. Grimes.\" may be used to endorse or promote products derived from this software 1758f0484fSRodney W. Grimes.\" without specific prior written permission. 1858f0484fSRodney W. Grimes.\" 1958f0484fSRodney W. Grimes.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2058f0484fSRodney W. Grimes.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2158f0484fSRodney W. Grimes.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2258f0484fSRodney W. Grimes.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2358f0484fSRodney W. Grimes.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2458f0484fSRodney W. Grimes.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2558f0484fSRodney W. Grimes.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2658f0484fSRodney W. Grimes.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2758f0484fSRodney W. Grimes.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2858f0484fSRodney W. Grimes.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2958f0484fSRodney W. Grimes.\" SUCH DAMAGE. 3058f0484fSRodney W. Grimes.\" 3158f0484fSRodney W. Grimes.\" @(#)bzero.3 8.1 (Berkeley) 6/4/93 3258f0484fSRodney W. Grimes.\" 33*f0788bbfSMarcelo Araujo.Dd August 24, 2015 3458f0484fSRodney W. Grimes.Dt BZERO 3 35a307d598SRuslan Ermilov.Os 3658f0484fSRodney W. Grimes.Sh NAME 3778b59024SXin LI.Nm bzero , 3878b59024SXin LI.Nm explicit_bzero 3958f0484fSRodney W. Grimes.Nd write zeroes to a byte string 4025bb73e0SAlexey Zelkin.Sh LIBRARY 4125bb73e0SAlexey Zelkin.Lb libc 4258f0484fSRodney W. Grimes.Sh SYNOPSIS 43bc0ad8e7SRobert Drehmel.In strings.h 4458f0484fSRodney W. Grimes.Ft void 4558f0484fSRodney W. Grimes.Fn bzero "void *b" "size_t len" 4678b59024SXin LI.Ft void 4778b59024SXin LI.Fn explicit_bzero "void *b" "size_t len" 4858f0484fSRodney W. Grimes.Sh DESCRIPTION 4958f0484fSRodney W. GrimesThe 5058f0484fSRodney W. Grimes.Fn bzero 5158f0484fSRodney W. Grimesfunction 5258f0484fSRodney W. Grimeswrites 5358f0484fSRodney W. Grimes.Fa len 5458f0484fSRodney W. Grimeszero bytes to the string 5558f0484fSRodney W. Grimes.Fa b . 5658f0484fSRodney W. GrimesIf 5758f0484fSRodney W. Grimes.Fa len 5858f0484fSRodney W. Grimesis zero, 5958f0484fSRodney W. Grimes.Fn bzero 6058f0484fSRodney W. Grimesdoes nothing. 6178b59024SXin LI.Pp 6278b59024SXin LIThe 6378b59024SXin LI.Fn explicit_bzero 6478b59024SXin LIvariant behaves the same, but will not be removed by a compiler's dead store 6578b59024SXin LIoptimization pass, making it useful for clearing sensitive memory such as a 6678b59024SXin LIpassword. 6758f0484fSRodney W. Grimes.Sh SEE ALSO 6858f0484fSRodney W. Grimes.Xr memset 3 , 6958f0484fSRodney W. Grimes.Xr swab 3 7058f0484fSRodney W. Grimes.Sh HISTORY 7158f0484fSRodney W. GrimesA 7258f0484fSRodney W. Grimes.Fn bzero 7358f0484fSRodney W. Grimesfunction 7458f0484fSRodney W. Grimesappeared in 7558f0484fSRodney W. Grimes.Bx 4.3 . 76bc0ad8e7SRobert DrehmelIts prototype existed previously in 77fe08efe6SRuslan Ermilov.In string.h 78bc0ad8e7SRobert Drehmelbefore it was moved to 79fe08efe6SRuslan Ermilov.In strings.h 80bc0ad8e7SRobert Drehmelfor 81bc0ad8e7SRobert Drehmel.St -p1003.1-2001 82bc0ad8e7SRobert Drehmelcompliance. 8378b59024SXin LI.Pp 8478b59024SXin LIThe 8578b59024SXin LI.Fn explicit_bzero 8678b59024SXin LIfunction first appeared in 8778b59024SXin LI.Ox 5.5 8878b59024SXin LIand 8978b59024SXin LI.Fx 11.0 . 90*f0788bbfSMarcelo Araujo.Pp 91*f0788bbfSMarcelo Araujo.St -p1003.1-2008 92*f0788bbfSMarcelo Araujoremoves the specification of 93*f0788bbfSMarcelo Araujo.Fn bzero 94*f0788bbfSMarcelo Araujoand it is marked as LEGACY in 95*f0788bbfSMarcelo Araujo.St -p1003.1-2004 . 96*f0788bbfSMarcelo AraujoFor portability with other systems new programs should use 97*f0788bbfSMarcelo Araujo.Xr memset 3 . 98