p3-3.c

UNIX程序设计教程

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "err_exit.h"
int main(void)
{
    int fd;
    if((fd = open("myoutput",O_WRONLY|O_CREAT,0644)) == -1)
        err_exit("myoutput ");
    /* 重复标准输出至描述字fd相连的文件myoutput */
    if (dup2(fd,STDOUT_FILENO) == -1)
        err_exit("Redirect standar output failed");
    printf("this is a test program for redirect \n");
    close(fd);
}