/* _rename.c -- Implementation of the low-level rename() routine
*
* Copyright (c) 2004 National Semiconductor Corporation
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <alloca.h>
#include <errno.h>
int _rename (char *from, char *to)
{
void* buf;
int f_from;
int f_to;
int size;
f_from = open(from,O_RDONLY);
if (f_from < 0)
{
errno = ENOENT;
return -1;
};
f_to = open(to,O_CREAT|O_WRONLY|O_EXCL);
if (f_to < 0)
{
close(f_from);
errno = EACCES;
return -1;
};
buf = alloca(32768);
do
{
size = read(f_from, buf, 32768);
if (size >= 0)
size = write(f_to, buf, size);
}while (size == 32768);
close(f_to);
close(f_from);
if (size == -1)
{
errno = EACCES;
return -1;
};
return (0);
};