bzero —
write zeroes to a byte string
Standard C Library (libc, -lc)
#include <strings.h>
void
  
  bzero(void
    *b, size_t
  len);
The bzero() function writes len
  zero bytes to the string b. If len
  is zero, bzero() does nothing.
The bzero() function conforms to IEEE
  Std 1003.1-2001 (“POSIX.1”). The IEEE
  Std 1003.1-2004 (“POSIX.1”) revision marked it as legacy
  and recommended the use of
  memset(3) instead. The
  IEEE Std 1003.1-2008 (“POSIX.1”)
  revision removed bzero() from the specification.
A bzero() function appeared in
  4.3BSD.