| memset(3) | Library Functions Manual | memset(3) |
NAME
memset - memory set
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <string.h> // see memory.h(3head)
void *memset(size_t n;
void a[n], int c, size_t n);
DESCRIPTION
The memset() function fills the first n bytes of the memory area pointed to by a with the constant byte c.
RETURN VALUE
The memset() function returns a pointer to the memory area a.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| memset () | Thread safety | MT-Safe |
STANDARDS
C11, POSIX.1-2008.
HISTORY
POSIX.1-2001, C89, SVr4, 4.3BSD.
CAVEATS
If the compiler deduces that the operation is unnecessary, it may totally or partially remove the call. To ensure the setting happens regardless of optimizations, use memset_explicit(3).
SEE ALSO
memory.h(3head), bzero(3), swab(3), wmemset(3)
| 2026-08-10 | Linux man-pages 6.19 |