1、完成标准io的单字符、字符串、格式化、模块化实现两个文件的拷贝；

#include <myhead.h>
typedef struct sockaddr_in addr_in_t;
typedef struct sockaddr addr_t;
typedef struct sockaddr_un addr_un_t;
int main(int argc, const char *argv[])
{
	FILE* rfp = fopen(argv[1],"r");
	if(NULL == rfp){
		perror("fopen err:");
		return -1;
	}
	//字符拷贝
	FILE* wfp = fopen("zifu.c","w");
	if(NULL == wfp){
		perror("zifufopen err:");
		return -1;
	}
	printf("0\n");
	while(1){
		char ch = fgetc(rfp);
		if(ch == EOF)break;
		fputc(ch,wfp);
	}
	printf("1\n");
	//字符串拷贝
	FILE* ps = fopen("zifuchuan.c","w");
	char arr[12] = "";
	if(NULL == ps){
		perror("zifuchuanfopen err:");
		return -1;
	}
	fseek(rfp,0,SEEK_SET);
	while(1){
		char*res = fgets(arr,sizeof(arr),rfp);
		if(res == NULL)break;
		fputs(arr,ps);
	}
	printf("2\n");
	//格式拷贝
	FILE* pf = fopen("geshi.c","w");
	if(NULL == pf){
		perror("geshifopen err:");
		return -1;
	}
		fseek(rfp,0,SEEK_SET);
	while(1){
		char ch;
		int s = fscanf(rfp,"%c",&ch);
		if(s==EOF)break;
		fprintf(pf,"%c",ch);
	}
	printf("3\n");
	//Mo_Kuai拷贝
	FILE* fr = fopen("mokuai.c","w");
	if(NULL == pf){
		perror("mokuaifopen err:");
		return -1;
	}
	fseek(rfp,0,SEEK_SET);
	while(1){
		int res = fread(arr,sizeof(arr),1,rfp);
	//	if(res == )break;
		if(feof(rfp))break;
		fwrite(arr,sizeof(arr),1,fr);
	}
	fclose(fr);
	fclose(rfp);
	fclose(wfp);
	fclose(ps);
	fclose(pf);
	return 0;
}

2、实现注册和登录功能，将注册账号和密码存储到文件中，登录时遍历文件如果存在就登录成功否则登录失败

#include <myhead.h>
typedef struct sockaddr_in addr_in_t;
typedef struct sockaddr addr_t;
typedef struct sockaddr_un addr_un_t;
typedef struct {//定义账号密码结构体
	char zhanghao[20];
	char mima[20];
}deng_lu;
int main(int argc, const char *argv[])
{
	FILE* zfd = fopen("shujuku.txt","a");
	FILE* dfd = fopen("shujuku.txt","r");
	deng_lu yong_hu,shu_ju;//用于接受读取文件中的用户密码
	while(1){
	printf("请选择操作\n");
	printf("\t1、登录\n");
	printf("\t2、注册\n");
	printf("\t3  tuichu\n");
	int a;
	scanf("%d",&a);

	if(a==2){  //注册功能
		printf("请输入账号和密码中间以空格隔开\n");
		scanf("%s %s",yong_hu.zhanghao,yong_hu.mima);
		fseek(dfd,0,SEEK_SET);
		int t=1;
		while(!feof(dfd)){
			fread(&shu_ju,sizeof(deng_lu),1,dfd);
			if(strcmp(shu_ju.zhanghao,yong_hu.zhanghao)==0){
				printf("用户已存在\n");t=0;break;
			}}
		if(t==1){
			fwrite(&yong_hu,sizeof(deng_lu),1,zfd);
			fflush(zfd);
			printf("注册成功\n");
		}}
	else if(a==1){ //登录功能
			//fread(&yong_hu,sizeof(deng_lu),1,0);
		printf("请输入账号和密码中间以空格隔开\n");
		scanf("%s %s",yong_hu.zhanghao,yong_hu.mima);
		int s=0;
		fseek(dfd,0,SEEK_SET);
		while(1){
			int c = fread(&shu_ju,sizeof(deng_lu),1,dfd);
			//printf("%s %s\n",shu_ju.zhanghao,shu_ju.mima);
			if(c==0)break;
			if(strcmp(shu_ju.zhanghao,yong_hu.zhanghao)==0&&strcmp(shu_ju.mima,yong_hu.mima)==0){
				printf("登陆成功\n");
				s=1;break;
		}}
		if(s==0){printf("用户不存在或密码错误\n");}
	}
	else if(a==3){
		return 0;
	}
	else{
		printf("不存在该功能\n");
	}
	}
	fclose(zfd);
	fclose(dfd);
	return 0;
}