BZERO(3)               FreeBSD Library Functions Manual               BZERO(3)

NAME
     bzero, explicit_bzero - write zeroes to a byte string

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 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).

FreeBSD 13.1-RELEASE-p6         August 24, 2015        FreeBSD 13.1-RELEASE-p6