用户登录系统的密码代码

#include

#include

#include

#include

#include

typedef struct p

{

char name[20];

char secret[20];

struct p*next;

}pass;

//保存密码模块

void save(pass*load)

{

FILE *fp;

fp=fopen("c:\\password.txt","wt");

if(fp==NULL)

{

printf("写文件错误，任意键退出！\n");

exit(1);

}

fprintf(fp,"%s %s\n",load->name,load->secret);

printf("文件保存成功！按任意键返回\n");

fclose(fp);

}

//读入信息模块

pass* read()

{

FILE*fp;

pass *head,*p,*q,*r;

head=(pass *)malloc(sizeof(pass));

p=head;

fp=fopen("c:\\password.txt","rt");

if(fp==NULL)

{

printf("文件不存在！任意键新建\n");

}

while(!feof(fp))

{

q=(pass *)malloc(sizeof(pass));

fscanf(fp,"%s %s",q->name,q->secret);

p->next=q;

r=p;

p=q;

}

r->next=NULL;

return head;

fclose(fp);

}

//追加保存新用户信息

void addpass(pass *load)

{

FILE *fp;

fp=fopen("c:\\password.txt","a+");

if(fp==NULL)

{

printf("写文件错误，任意键退出！\n");

exit(1);

}

fputc('\n',fp);

fprintf(fp,"%s %s\n",load->name,load->secret);

printf("文件保存成功！按任意键返回\n");

fclose(fp);

}

//用户登录模块

pass *newuser()

{

pass *p;

int i=0,a;

char ch;

p=(pass *)malloc(sizeof(pass));

printf("输入用户名:\n");

flushall();

gets(p->name);

printf("输入您的密码\n");

flushall();

ch=getch();

while(ch!='\r')

{

if(ch=='\b')

{

a=i;

for(;a<=20;a++)

{

p->secret[a-1]=p->secret[a];

}

printf("\b \b");

ch=getch();

i--;

}

else

{

p->secret[i]=ch;

i++;

printf("*");

flushall();

ch=getch();

}

}

p->secret[i]='\0';

printf("\n");

return p;

}

//主调函数

void passwd()

{

pass *momo,*p,*q;

int s=0,flag=1;

char ch,cha;

int i=0,a;

FILE *fp;

momo=(pass *)malloc(sizeof(pass));

p=(pass *)malloc(sizeof(pass));

q=(pass *)malloc(sizeof(pass));

fp=fopen("c:\\password.txt","rt");

if(fp==NULL)

{

printf("C盘暂无存储，请新建\n");

momo=newuser();

save(momo);

}

else

{

while(s<3)

{

momo=(pass *)malloc(sizeof(pass));

i=0;

printf("输入用户名:\n");

flushall();

gets(momo->name);

printf("输入您的密码\n");

flushall();

ch=getch();

while(ch!='\r')

{

if(ch=='\b')

{

a=i;

for(;a<=20;a++)

{

momo->secret[a-

1]=momo->secret[a];

}

printf("\b \b");

i--;

ch=getch();

}

else

{

momo->secret[i]=ch;

i++;

printf("*");

flushall();

ch=getch();

}

}

momo->secret[i]='\0';

printf("\n");

for(p=read();p!=NULL;p=p->next)

{

if(strcmp(p->name,momo->name)==0&&strcmp(p->secret,momo->secret)==0)

{

printf("*********欢迎进入:*********\n");

printf("是否新建用户?(y)");

flushall();

ch=getchar();

while(ch=='y')

{

i=0;

printf("输入新用户名:\n");

flushall();

gets(q->name);

printf("输入密码:\n");

flushall();

cha=getch();

while(cha!='\r')

{

if(cha=='\b')

{

a=i;

for(;a<=20;a++)

{

q->secret[a-1]=q->secret[a];

}

printf("\b \b");

cha=getch();

i--;

}

else

{

q->secret[i]=cha;

i++;

printf("*");

flushall();

cha=getch();

}

}

q->secret[i]='\0';

for(p=read();p!=NULL;p=p->next)

{

if(strcmp(p->name,q->name)==0)

{

flag=0;

break;

}

}

if(flag==0)

{

printf("用户名已存在,请新建:\n");

printf("是否继续新建用户?(y)");

flushall();

ch=getchar();

flag=1;

}

else

{

addpass(q);

break;

}

}

return ;

}

}

if(p==NULL)

{

printf("用户非法!重新输入\n");

}

s++;

}

if(s==3)

{

printf("用户非法!\n");

exit(1);

}

}

}