NAME
bzero,
explicit_bzero —
write zeroes to a byte
string
LIBRARY
library “libc”
SYNOPSIS
#include
<strings.h>
void
bzero(void
*b, size_t
len);
void
explicit_bzero(void
*b, size_t
len);
DESCRIPTION
Thebzero()
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
HISTORY
A bzero() function appeared in
4.3BSD. 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).