1.stderr 不可以重定向
2.freopen 函数实现重定向,不需要借助dos。
#define _CRT_SECURE_NO_WARNINGS
#define OUTPATH "C:\\Users\\michael\\Desktop\\0730.txt"
#define INPATH "C:\\Users\\michael\\Desktop\\ipconfig.txt"
#include <stdlib.h>
#include <stdio.h>
void main()
{
char str[100] = { 0 };
freopen(INPATH, "r", stdin);
scanf("%s", str);
freopen(OUTPATH, "w", stdout);
printf("%s\n", system(str));
fclose(stdin);
fclose(stdout);
}