linux 复制文件代码

#include "apue.h"

#define BUFFSIZE  4096


int main(void)
{
	int n ;
	char buf[BUFFSIZE];
	
	
	while((n = read(STDIN_FILENO,buf,BUFFSIZE))>0)
		if (write(STDIN_FILENO,buf,n) != n)
			
			err_sys("write error");
		
		if (n<0)
			err_sys("read error");
		
		exit(0);
}