MEMCPY(3) Linux Programmer's Manual MEMCPY(3)NAME
memcpy - copy memory area
SYNOPSIS
#include <string.h>
void *memcpy(void *dest, const void *src, size_t n);
DESCRIPTION
The memcpy() function copies n bytes from memory area src to memory area dest. The memory areas should not overlap. Use memmove(3) if the
memory areas do overlap.
RETURN VALUE
The memcpy() function returns a pointer to dest.
CONFORMING TO
SVr4, 4.3BSD, C89, C99, POSIX.1-2001.
SEE ALSO bcopy(3), memccpy(3), memmove(3), mempcpy(3), strcpy(3), strncpy(3), wmemcpy(3)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
1993-04-10 MEMCPY(3)
Check Out this Related Man Page
MEMCPY(3) Linux Programmer's Manual MEMCPY(3)NAME
memcpy - copy memory area
SYNOPSIS
#include <string.h>
void *memcpy(void *dest, const void *src, size_t n);
DESCRIPTION
The memcpy() function copies n bytes from memory area src to memory area dest. The memory areas must not overlap. Use memmove(3) if the
memory areas do overlap.
RETURN VALUE
The memcpy() function returns a pointer to dest.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
+----------+---------------+---------+
|Interface | Attribute | Value |
+----------+---------------+---------+
|memcpy() | Thread safety | MT-Safe |
+----------+---------------+---------+
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.
NOTES
Failure to observe the requirement that the memory areas do not overlap has been the source of significant bugs. (POSIX and the C stan-
dards are explicit that employing memcpy() with overlapping areas produces undefined behavior.) Most notably, in glibc 2.13 a performance
optimization of memcpy() on some platforms (including x86-64) included changing the order in which bytes were copied from src to dest.
This change revealed breakages in a number of applications that performed copying with overlapping areas. Under the previous implementa-
tion, the order in which the bytes were copied had fortuitously hidden the bug, which was revealed when the copying order was reversed. In
glibc 2.14, a versioned symbol was added so that old binaries (i.e., those linked against glibc versions earlier than 2.14) employed a mem-
cpy() implementation that safely handles the overlapping buffers case (by providing an "older" memcpy() implementation that was aliased to
memmove(3)).
SEE ALSO bcopy(3), bstring(3), memccpy(3), memmove(3), mempcpy(3), strcpy(3), strncpy(3), wmemcpy(3)COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the
latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
2017-09-15 MEMCPY(3)
Hi
Having a lil trouble with a rather simple application I'm writing. It so happens that I have to copy some data using memcpy() and so far I've been doing just fine compiling it with VC.Net and running it on Windows XP. Now I'm trying to port the thing to Solaris (which shouldn't really be too... (3 Replies)
Hello everybody,
I'm coding a test program for ARP protocol, and i don't know why i'm getting a SIGSEGV, i traced it with gdb and it says it's due to the memcpy function from /lib/libc.so.6.
Program received signal SIGSEGV, Segmentation fault.
0xb7e9e327 in memcpy () from /lib/libc.so.6
This... (5 Replies)
I am getting segmentation fault in memcpy.I have given sufficient memory but i dont know why it is occurring
char *finalptr = ( char *)malloc(1048576* sizeof(char));
finaloffset=0;have=685516;
memcpy(&(finalptr)+finaloffset,out,have);
finaloffset=685516;have=359910;... (23 Replies)