IOday1

#include 
#include 
#include 
int main(int argc, const char *argv[])
{
	FILE *fp=fopen("./usr.txt","r");
	if(NULL==fp)
	{
		perror("fopen");
		return -1;
	}
	char user[20];
	char pwd[20];
	printf("请输入用户名和密码用空格隔开:\n");
	scanf("%s %s",user,pwd);
	char user1[20];
	char pwd1[20];
	char str;
	while(1)
	{
		fscanf(fp,"%s",user1);
		if(strcmp(user,user1)==0)
		{
			fscanf(fp,"%s",pwd1);
			if(strcmp(pwd,pwd1)==0)
			{
				puts("登录成功");
				return 0;
			}
			puts("密码错误");
			return -1;	
		}
		if(fscanf(fp,"%c",&str)==EOF)
		{
			puts("用户不存在");
			return -1;
		
		}
	}
 
	return 0;
}