memset man page


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

memset — set bytes in memory


#include <string.h>

void *memset(void *s, int c, size_t n);


The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1‐2008 defers to the ISO C standard.

The memset() function shall copy c (converted to an unsigned char) into each of the first n bytes of the object pointed to by s.

Return Value

The memset() function shall return s; no return value is reserved to indicate an error.


No errors are defined.

The following sections are informative.

See Also

The Base Definitions volume of POSIX.1‐2008, <string.h>