ファイルリダイレクト

#define   _CRT_SECURE_NO_WARNINGS//      
#include<stdio.h>
#include<stdlib.h>

void main1()
{
	char str[100] = { 0 };
	scanf("%s", str);
	printf("str=%s
", str);
	system(str);




}

void main2()
{



	char str[100] = { 0 };
	fscanf(stdin,"%s", str);
	fprintf(stdout,"str=%s
", str);
	system(str);


}

//  5     5 calc
void  main3()
{
	char *path = "C:\\Users\\yincheng01\\Desktop\
ewcmd.txt";
	
	int num=0;
	char docmd[30] = { 0 };
	scanf("%d%s", &num, docmd);//      
	FILE *pf;
	pf = fopen(path, "w");//  
	if (pf == NULL)
	{
		printf("      ");
	}
	else
	{
		fprintf(pf, "for /l %%i in (1,1,%d) do %s", num, docmd);
		fclose(pf);
	}

    system("pause");
}

void main4()
{

	char cmd[100] = { 0 };
	int num = 0;
	char docmd[30] = { 0 };
	char *path = "C:\\Users\\yincheng01\\Desktop\
ewcmd.txt";
	FILE *pf = fopen(path, "r");//  
	if (pf == NULL)
	{
		printf("      ");
		return;
	}
	else
	{
		fscanf(pf, "for /l %%i in (1,1,%d) do %s", &num, docmd);
		printf("num=%d,docmd=%s", num, docmd);
	}


	system("pause");
}

void main()
{
	int num ;
	scanf("num=%d", &num);//      
	printf("num=%d", num);
	system("pause");
}

fprintf(pf, "for /l %%i in (1,1,%d) do %s", num, docmd);