dnonblock.c

用来编写 unix 环境下的守护程序的工具库

/* $Id: dnonblock.c 101 2005-11-18 20:39:12Z lennart $ */

/*
 * This file is part of libdaemon.
 *
 * libdaemon is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * libdaemon is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with libdaemon; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <fcntl.h>

#include "dnonblock.h"

int daemon_nonblock(int fd, int b) {
    int a;
    if ((a = fcntl(fd, F_GETFL)) < 0)
        return -1;

    if (b)
        a |= O_NDELAY;
    else
        a &= ~O_NDELAY;

    if (fcntl(fd, F_SETFL, a) < 0)
        return -1;

    return 0;
}