程序3-5 对一个文件描述符打开一个或多个文件状态标志

//http://blog.chinaunix.net/uid-24549279-id-71355.html
/*
 ============================================================================
 Name        : test.c
 Author      : blank
 Version     :
 Copyright   : Your copyright notice
 Description : 程序3-5 对一个文件描述符打开一个或多个文件状态标志
 ============================================================================
*/

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include "ourhdr.h"

/*
 * flags are file status flags to turn on
 */
void set_f1(int fd, int flags){
    int val;

    if ((val = fcntl(fd, F_GETFD, 0)) < 0){
        err_sys("fcntl F_GETFD error
");
    }

    // turn on
    val |= flags;

    if (fcntl(fd, F_SETFD, val) < 0){
        err_quit("fcntl F_SETFL error
");
    }
}

/*
 * flags are file status flags to turn off
 */
void del_f1(int fd, int flags){
    int val;

    if ((val = fcntl(fd, F_GETFD, 0)) < 0){
        err_sys("fcntl F_GETFD error
");
    }

    // turn off
    val &= ~flags;

    if (fcntl(fd, F_SETFD, val) < 0){
        err_quit("fcntl F_SETFL error
");
    }
}