原创 Linux dup系统调用

/*
 * main.c
 *
 *  Created on: 2024-6-11
 *      Author: root
 */
#include

#include

#include
#include
#include
#include



int main()
{

	int fd;

	if((fd=open("output",O_CREAT | O_RDWR,0644))==-1)
	{
		perror("open or creat file failed!");
		return 1;
	}
	close(1);
	dup(fd);
	close(fd);
	puts("this line dsta will output to file");






	return 0;
}
运行效果