NAME
memset —
write a byte to byte
string
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <string.h>
void *
memset(
void
*b,
int c,
size_t len);
DESCRIPTION
The
memset() function writes
len bytes
of value
c (converted to an unsigned char) to the string
b.
RETURN VALUES
The
memset() function returns the original value of
b.
Note that the compiler may optimize away a call to
memset() if
it can prove that the string will not be used by the program again, for
example if it is allocated on the stack and about to go out of scope. If you
want to guarantee that zeros are written to memory, for example to sanitize a
buffer holding a cryptographic secret, use
explicit_memset(3).
SEE ALSO
bzero(3),
explicit_memset(3),
swab(3)
STANDARDS
The
memset() function conforms to
ANSI
X3.159-1989 (“ANSI C89”).