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/* ==== readv.c ============================================================
* Copyright (c) 1995 by Chris Provenzano, proven@mit.edu
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Chris Provenzano.
* 4. The name of Chris Provenzano may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Description : Implementation of readv().
*
* 1.00 95/06/19 proven
* -Started coding this file.
*/
#ifndef lint
static const char rcsid[] = "$Id: readv.c,v 1.1 1998/07/21 13:20:22 peter Exp $";
#endif
#include "config.h"
#ifndef HAVE_SYSCALL_READV
#include <errno.h>
#include <unistd.h>
#include <sys/uio.h>
#include <sys/types.h>
/* ==========================================================================
* machdep_sys_readv()
*/
int machdep_sys_readv(int fd, struct iovec * vector, int count)
{
size_t bytes, i;
char *buffer;
int ret = 0;
/* Find the total number of bytes to be read. */
for (bytes = 0, i = 0; i < count; ++i)
bytes += vector[i].iov_len;
if (bytes) {
/*
* Allocate a temporary buffer to hold the data.
* Don't use alloca because threads tend to have smaller stacks.
*/
if ((buffer = (char *)malloc(bytes)) == NULL) {
return(-ENOMEM);
}
ret = (int)machdep_sys_read(fd, buffer, bytes);
/* Copy the data from memory specified by VECTOR to BUFFER */
for (i = 0, bytes = 0; ret > 0; ret -= vector[i].iov_len) {
memcpy(vector[i].iov_base, buffer + bytes,
ret > vector[i].iov_len ? vector[i].iov_len : ret);
bytes += vector[i].iov_len;
}
free(buffer);
}
return(ret);
}
#endif
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