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
(“ISO C99”) standard.
Issue 8
Austin Group Defect 448 is applied, adding a requirement that
memcpy () does not change the setting of
errno on valid input.