tail head cat sleep
QR code linking to this page

Manual Pages  — BZERO

NAME

bzero, explicit_bzero – write zeroes to a byte string

CONTENTS

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <strings.h>

void
bzero(void *b, size_t len);

void
explicit_bzero(void *b, size_t len);

DESCRIPTION

The bzero() function writes len zero bytes to the string b. If len is zero, bzero() does nothing.

The 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.

SEE ALSO

memset(3), swab(3)

HISTORY

A bzero() function appeared in BSD 4.3 . Its prototype existed previously in <string.h> before it was moved to <strings.h> for IEEE Std 1003.1-2001 ("POSIX.1") compliance.

The explicit_bzero() function first appeared in OpenBSD 5.5 and FreeBSD 11.0 .

IEEE Std 1003.1-2008 ("POSIX.1") removes the specification of bzero() and it is marked as LEGACY in IEEE Std 1003.1-2004 ("POSIX.1"). For portability with other systems new programs should use memset(3).


BZERO (3) August 24, 2015

tail head cat sleep
QR code linking to this page


Please direct any comments about this manual page service to Ben Bullock. Privacy policy.

UNIX is a four-letter word!