复制文件句柄dup2 函数

函数简介　　

函数名: dup2

功 能: 复制文件句柄

用 法: int dup2(int oldhandle, int newhandle);

#include <sys\stat.h>　　#include <string.h>　　#include <fcntl.h>　　#include <io.h>　　int main(void)　　{　　#define STDOUT 1　　int nul, oldstdout;　　char msg[] = "This is a test";　　/* create a file */　　nul = open("DUMMY.FIL", O_CREAT | O_RDWR,　　S_IREAD | S_IWRITE);　　/* create a duplicate handle for standard　　output */　　oldstdout = dup(STDOUT);　　/*　　redirect standard output to DUMMY.FIL　　by duplicating the file handle onto the　　file handle for standard output.　　*/　　dup2(nul, STDOUT);　　/* close the handle for DUMMY.FIL */　　close(nul);　　/* will be redirected into DUMMY.FIL */　　write(STDOUT, msg, strlen(msg));　　/* restore original standard output　　handle */　　dup2(oldstdout, STDOUT);　　/* close duplicate handle for STDOUT */　　close(oldstdout);　　return 0;　　}