memset(3) - BetterMan

memset(3)

fill memory with a constant byte

distropkg manpages-dev@6.9.1-1dataset 2026-04-01T06:19:02Z+debian+ec4110e+mandoc:1.14.6-4

Synopsis

#include <string.h>
void *memset(void 
s
[.
n
], int 
c
, size_t 
n
);

—

NAME

memset - fill memory with a constant byte

Standard C library (libc, -lc)

bash

#include <string.h>

bash

void *memset(void \ns\n[.\nn\n], int \nc\n, size_t \nn\n);

The memset() function fills the first n bytes of the memory area pointed to by s with the constant byte c.

The memset() function returns a pointer to the memory area s.

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
memset ()	Thread safety	MT-Safe

C11, POSIX.1-2008.

POSIX.1-2001, C89, SVr4, 4.3BSD.