NAME

memcpy — copy bytes in memory

SYNOPSIS

#include <string.h>

void *memcpy(void *restrict s1, const void *restrict s2, size_t n);


DESCRIPTION

^[CX] 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.1-2024 defers to the ISO C standard.

The memcpy() function shall copy n bytes from the object pointed to by s2 into the object pointed to by s1. If copying takes place between objects that overlap, the behavior is undefined.

^[CX] The memcpy() function shall not change the setting of errno on valid input.

RETURN VALUE

The memcpy() function shall return s1; no return value is reserved to indicate an error.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

The memcpy() function does not check for the overflow of the receiving memory area.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

XBD <string.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

The memcpy() prototype is updated for alignment with the ISO/IEC 9899:1999 standard.

Issue 8

Austin Group Defect 448 is applied, adding a requirement that memcpy() does not change the setting of errno on valid input.