/* Copyright (C) 2002, 2003 Mads Martin Joergensen <mmj at mmj.dk>
 *
 * $Id: writen.c,v 1.2 2004/06/16 21:11:55 mmj Exp $
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <sys/types.h>
#include <unistd.h>
#include <errno.h>

/**
 * write n bytes to a descriptor 
 */

ssize_t writen(int fd, const void *vptr, size_t n)
{
	size_t nleft;
	ssize_t nwritten;
	const char *ptr;

	ptr = (const char*)vptr;
	nleft = n;
	while(nleft > 0) {
		if((nwritten = write(fd, ptr, nleft)) < 0) {
			if(errno == EINTR) {
				nwritten = 0; /* and call write() again */
			} else {
				return -1; /* error, caller can check errno */
			}
		}
		nleft -= nwritten;
		ptr += nwritten;
	}
	return n;
}