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[thirdparty/man-pages.git] / man3 / mempcpy.3

.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
.\" Distributed under GPL
.\" Heavily based on glibc infopages, copyright Free Software Foundation
.\"
.\" aeb, 2003, polished a little
.TH MEMPCPY 3 2008-08-12 "GNU" "Linux Programmer's Manual"
.SH NAME
mempcpy, wmempcpy  \- copy memory area
.SH SYNOPSIS
.nf
.BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
.br
.B #include <string.h>
.sp
.BI "void *mempcpy(void *" dest ", const void *" src ", size_t " n );
.sp
.BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
.br
.B #include <wchar.h>
.sp
.BI "wchar_t *wmempcpy(wchar_t *" dest ", const wchar_t *" src ", size_t " n );
.fi
.SH DESCRIPTION
The
.BR mempcpy ()
function is nearly identical to the
.BR memcpy (3)
function.
It copies
.I n
bytes from the object beginning at
.I src
into the object pointed to by
.IR dest .
But instead of returning the value of
.I dest
it returns a pointer to the byte following the last written byte.
.PP
This function is useful in situations where a number of objects
shall be copied to consecutive memory positions.
.PP
The
.BR wmempcpy ()
function is identical but takes
.I wchar_t
type arguments and copies
.I n
wide characters.
.SH "RETURN VALUE"
\fIdest\fP + \fIn\fP.
.SH VERSIONS
.BR mempcpy ()
first appeared in glibc in version 2.1.
.SH "CONFORMING TO"
This function is a GNU extension.
.SH "EXAMPLE"
.nf
void *
combine(void *o1, size_t s1, void *o2, size_t s2)
{
    void *result = malloc(s1 + s2);
    if (result != NULL)
        mempcpy(mempcpy(result, o1, s1), o2, s2);
    return result;
}
.fi
.SH "SEE ALSO"
.BR memccpy (3),
.BR memcpy (3),
.BR memmove (3),
.BR wmemcpy (3)