如何形成(建立)单链表
要做一个小系统(管理学生信息),文件操作和链表操作都不太会,在vi下编译通过之后,运行却显示"已杀死"问题主要在建立链表和文件操作,求解救 #include"student_info.h"
#define Name "usr_info.conf"
Node * insert(Node *tamp);
void search(void);
void passwd(Node *);
void saveinfo(void);
Node * loading(void);
void fileload(void);
void addinfo(void);
void delete(void);
Node *head;
void saveinfo(void)
{
Node *write;
FILE *info;
info = fopen(Name,"w+");
if((write = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
write = head;
while(write != NULL && write->next != NULL)
{
if(write == NULL)
write = write->next;
fwrite(write,sizeof(Node), 1, info);
write = write->next;
}
free(write);
fclose(info);
}
void delete(void)
{
char name[32];
Node *del;
if((head = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
del = head;
printf("Please input the user be deleted!:");
scanf("%s",name);
while( del != NULL)
{
if(strcmp(name, del->usr_name) == 0)
{
del = NULL;
printf("删除成功!");
}
del = del->next;
}
}
void passwd(Node *x )
{
int i;
char a[18], b[18];
printf("请输入新密码：");
scanf("%s",a);
printf("请确认所输入密码：");
scanf("%s",b);
if(strcmp(a, b) == 0)
{
strcpy(x->password, b);
insert(x);
printf("修改成功！");
}
else
passwd(loading());
}
Node * loading(void)
{
Node *load, *p;
int j, i;
if((p = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
p = head;
if((load = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
printf("登录用户名：");
scanf("%s",load->usr_name);
for(j = 0; j < 2; j++)
{
while(strcmp(load->usr_name, p->usr_name) == 0 )
{
printf("登录密码：");
scanf("%s", load->password);
if(strcmp(load->password, p->password) == 0)
{
printf("登录成功！\n");
printf("%d\t%s\n%d\t%s\t%s\t", p->auth, p->usr_name, p->id, p->stu_name, p->major);
for(i = 0; i < 3; i++)
printf("%s:%f\n", p->s[i].course_name, p->s[i].score);
return p;
}
else
continue;
p = p->next;
}
}
if( j == 3) printf("用户不存在");
return NULL;
}
void search(void)
{
int j, i;
Node *sear, *t;
if((t = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
sear = head;
printf("请输入要查询的用户:");
scanf("%s",t->usr_name);
for(j = 0; j < 2; j++)
{
while(sear == NULL)
{
if(strcmp(t->usr_name, sear->usr_name) == 0)
{
printf("%d\t%s\n%d\t%s\t%s\t", sear->auth, sear->usr_name, sear->id, sear->stu_name, sear->major);
for(i = 0; i < 3; i++)
printf("%s:%f\n", sear->s[i].course_name, sear->s[i].score);
}
sear = sear->next;
}
}
if(j == 2)
{
printf("用户不存在！请重新输入！");
search();
}
}
Node * insert(Node *tamp)
{
Node *end, *buff;
if((head = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
if((buff = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
if((end = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
if(head == NULL)
{ head = tamp; head->next = end;}
while(end == NULL)
{
buff = end;
buff = tamp;
end = buff->next;
}
return head;
free(tamp);free(buff);free(end);
}
void addinfo(void)
{
int i, change = 0;
Node *add;
if((add = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
printf("Please input user's group: student(0) or manager(1):");
scanf("%d", &add->auth);
printf("Please input user's name:");
scanf("%s", add->usr_name);
printf("Please input user's password, the namber of password no more than 18:");
scanf("%s", add->password);
if(add->auth == 0)
{
printf("Please input student's id number:");
scanf("%d", &add->id);
printf("Please input student's major, the number of major no more than 32:");
scanf("%s", add->major);
for(i = 0; i < 3; i++)
{
printf("Pleaseinput the score of %d:",i+1);
scanf("%s,%f",add->s[i].course_name, add->s[i].score);
}
}
printf("%d\t%s\n%d\t%s\t%s\t", add->auth, add->usr_name, add->id, add->stu_name, add->major);
for(i = 0; i < 3; i++)
printf("%s:%f\n", add->s[i].course_name,add->s[i].score);
printf("Would you want to change? input any but 0 to change\n");
scanf("%d",&change);
if(change != 0)
addinfo();
insert(add);
free(add);
}
void fileload(void)
{
FILE *info;
Node *tamp;
if((tamp = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
info = fopen (Name , "r");
if(info == NULL)
info = fopen(Name, "a+");
fclose(info);
info = NULL;
info = fopen(Name, "r+");
if(info == NULL)
{
printf("Open ERROR!\n");
exit(0);
}
while(1)
{
fread(tamp, sizeof(Node), 1, info);
if(tamp == NULL)
break;
insert(tamp);
}
free(tamp);
fclose(info);
}
void manu(void)
{
int select = 0;
Node *l;
if((l = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
while(1)
{
printf("=======================================================================================\n");
printf("1 loading\t2 addinfo\t3 search\t4 passwd\t5 delete\t6 saveinfo\t7 exit\n");
printf("=======================================================================================\n");
printf("Please input your select:");
scanf("%d", &select);
switch(select)
{
case 1:
if(head == NULL)
{
printf("have no user!Please Add Information!\n");
addinfo();
}
else
{
l = loading();
manu();
break;
}
case 2:
if( l->auth == 1)
{ addinfo(); manu(); break;}
else
printf("You are limited!Try again!\n");
case 3:search();manu();break;
case 4:passwd( l );manu();break;
case 5:
if(l->auth == 1) delete();
else
printf("You are limited!");
manu();
break;
case 6:saveinfo();manu();break;
case 7:exit(0);break;
default:
printf("Try again!\n");manu;
}
}
}
int main(int argc, char *argv[])
{
if((head = (Node *)malloc(sizeof(Node))) == NULL)
{
printf("can't malloc!");
exit(0);
}
fileload( );
printf("Administrator of Student Information Manage\n");
manu();
return 0;
}
