writev.c
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上传日期:2007-04-14
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文件大小:3k
- /* ==== writev.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 writev().
- *
- * 1.00 95/06/19 proven
- * -Started coding this file.
- */
- #ifndef lint
- static const char rcsid[] = "$Id$";
- #endif
- #include "config.h"
- #ifndef HAVE_SYSCALL_WRITEV
- #include <errno.h>
- #include <unistd.h>
- #include <sys/uio.h>
- #include <sys/types.h>
- /* ==========================================================================
- * machdep_sys_writev()
- *
- * modified from the GNU C Library posix/writev.c
- */
- int machdep_sys_writev(int fd, struct iovec * vector, int count)
- {
- size_t bytes, i;
- char *buffer;
- int ret;
- /* Find the total number of bytes to be written. */
- 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);
- }
- /* Copy the data from memory specified by VECTOR to BUFFER */
- for (ret = 0, i = 0; i < count; ++i) {
- memcpy(buffer + ret, vector[i].iov_base, vector[i].iov_len);
- ret += vector[i].iov_len;
- }
- } else {
- buffer = NULL;
- }
- ret = (int)machdep_sys_write(fd, buffer, bytes);
- if (buffer)
- free(buffer);
- return(ret);
- }
- #endif