软件工程课程设计图书管理系统

} }

Book *Query(Book *head,char *name) { Book *p; p=head;

while(strcmp(name,p->Name)!=0&&p->next!=NULL) p=p->next;

if(strcmp(name,p->Name)==0) /*找到了，返回结点地址*/ return(p);

else /*找不到返回空指针*/ return(NULL); }

void Query_a_record(Book *head) { char name[20]; Book *p;

scanf(\ p=Query(head,name); if(p!=NULL) /*找到了*/

{ printf(\ p->Name,p->all,p->left,p->borrow); } else

printf(\找不到*/ }

Book *AddfromText(Book *head,char *filename) { FILE *fp; int n,i;

if((fp=fopen(filename,\

{printf(\打不开所指定文件*/ return(head);}

fscanf(fp,\待插入记录个数*/ for(i=0;i

p=(Book *)malloc(LEN); fgetc(fp); /*读取换行符*/

fscanf(fp,\ head=Insert(head,p); /*插入结点*/ }

printf(\ fclose(fp); return(head); }

Book *WritetoText(Book *head,char *filename) {FILE *fp;Book *p; if(head==NULL)

{printf(\

return(head);}

fp=fopen(filename,\打开文件*/ p=head; while(p!=NULL)

{ fprintf(fp,\文件输出

*/

p=p->next;}

printf(\输出写到文件完毕的信息*/ fclose(fp); return(head); }

void Quit(Book *head) {Book *p,*p1,*p2;FILE *fp; char filename[]=\ p2=p1=head; if(head!=NULL)

{fp=fopen(filename,\打开文件*/ p=head; while(p!=NULL)

{ fprintf(fp,\文件输出*/ p=p->next;}

printf(\输出写到文件完毕的信息*/ fclose(fp);}

while(p1!=NULL) /*p1指向的结点不是空指针*/ {p2=p1->next;

free(p1); /*释放存储空间*/ p1=p2; /*p1后移一个结点*/ }}