dup

DUPDUP是1，2-苯二甲酸二正十一酯，不溶于水，主要是作为增塑剂来使用的，溶于酯类。

DUPdup 在汇编中是一条伪指令，用来重复初始化数据

用法举例：

str1 db 10 dup ("!@#") ;这就是十个！@#

函数名: dup

功 能: 复制一个文件句柄

用 法: int dup(int handle);

程序例:

#include <string.h>

#include <stdio.h>

#include <conio.h>

#include <io.h>

void flush(FILE *stream);

int main(void)

{

FILE *fp;

char msg[] = "This is a test";

/* create a file */

fp = fopen("DUMMY.FIL", "w");

/* write some data to the file */

fwrite(msg, strlen(msg), 1, fp);

clrscr();

printf("Press any key to flush

DUMMY.FIL:");

getch();

/* flush the data to DUMMY.FIL without

closing it */

flush(fp);

printf("

File was flushed, Press any

key to quit:");

getch();

return 0;

}

void flush(FILE *stream)

{

int duphandle;

/* flush TC's internal buffer */

fflush(stream);

/* make a duplicate file handle */

duphandle = dup(fileno(stream));

/* close the duplicate handle to flush the

DOS buffer */

close(duphandle);

}