软件工程（C编码实践篇） 实验四：用可重用的链表模块来实现命令行菜单小程序V2.5

一、实验要求1.用可重用的链表模块来实现命令行菜单小程序，执行某个命令时调用一个特定的函数作为执行动作；2.链表模块的接口设计要足够通用，命令行菜单小程序的功能保持不变；3.可以将通用的Linktable模块集成到我们的menu程序中；4.接口规范。先贴出本文的gitbub地址：https://github.com/Ulov888/lab4以及最终运行截图：二、实验过程在上周的基础上，本周添加了新的任务，使用可重用的链表模块来实现命令行程序，那么就从这个链表模块写起吧，分别创建linktable.c和linktable.h文件linktable.c

#include <stdio.h>#include <stdlib.h>#include "linktable.h"tLinkTable* CreateLinkTable(){tLinkTable* pLinkTable=(tLinkTable*)malloc(sizeof(tLinkTable));if(pLinkTable == NULL){return NULL;}pLinkTable->Head=NULL;pLinkTable->Tail=NULL;pLinkTable->num=0;return pLinkTable;}int DelLinkTable(tLinkTable* pLinkTable){if(pLinkTable ==NULL){return FAILURE;}while(pLinkTable->Head != NULL){tLinkNode* pNode = pLinkTable->Head;pLinkTable->Head = pLinkTable->Head->Next;free(pNode);pLinkTable->num--;}pLinkTable->Head = NULL;pLinkTable->Tail = NULL;free(pLinkTable);return SUCCESS;}int AddLinkNode(tLinkTable* pLinkTable, tLinkNode* pNode){if(pLinkTable == NULL ||pNode == NULL){return FAILURE;}pNode->Next = NULL;if(pLinkTable->Head == NULL){pLinkTable->Head = pNode;}if(pLinkTable->Tail == NULL){pLinkTable->Tail = pNode;}else{pLinkTable->Tail->Next = pNode;pLinkTable->Tail = pLinkTable->Tail->Next;}pLinkTable->num++;return SUCCESS;}int DelLinkNode(tLinkTable* pLinkTable, tLinkNode* pNode){if(pLinkTable ==NULL || pNode == NULL){return FAILURE;}tLinkNode* p = pLinkTable->Head;if(pLinkTable->Head == pNode){pLinkTable->Head = pLinkTable->Head->Next;free(p);pLinkTable->num--;}if(pLinkTable->num ==0){pLinkTable->Tail=NULL;return SUCCESS;}while(p!= NULL){if(p->Next == pNode){tLinkNode* q = p->Next;p->Next = p->Next->Next;free(q);pLinkTable->num--;if(pLinkTable->num == 0){pLinkTable->Tail = NULL;}return SUCCESS;}p = p->Next;}return FAILURE;}tLinkNode* GetHeadNode(tLinkTable* pLinkTable){if(pLinkTable ==NULL||pLinkTable->Head==NULL){return NULL;}return pLinkTable->Head;}tLinkNode* GetTailNode(tLinkTable* pLinkTable){if(pLinkTable ==NULL||pLinkTable->Tail==NULL){return NULL;}return pLinkTable->Tail;}tLinkNode* GetNextNode(tLinkTable* pLinkTable,tLinkNode *pNode){if(pLinkTable==NULL||pNode==NULL){return NULL;}tLinkNode* p=pLinkTable->Head;while(p!=NULL){if(p==pNode){return p->Next;}p=p->Next;}return NULL;}

linktable.h

#ifndef _LINK_LIST_H_#define _LINK_LIST_H_#define SUCCESS 0#define FAILURE -1typedef struct LinkNode{struct LinkNode *Next;}tLinkNode;typedef struct LinkTable{tLinkNode *Head;tLinkNode *Tail;int num;}tLinkTable;tLinkTable* CreatLinkTable();int DelLinkTable(tLinkTable *pLinkTable);int AddLinkNode(tLinkTable *pLinkTable,tLinkNode* pNode);int DelLinkNode(tLinkTable *pLinkTable,tLinkNode* pNode);tLinkNode* GetHeadNode(tLinkTable* pLinkTable);tLinkNode* GetTailNode(tLinkTable* pLinkTable);tLinkNode* GetNextNode(tLinkTable* pLinkTable,tLinkNode *pNode);#endif

在上周的作业里，也要做如下修改：对linklist.c

tDataNode * FindCmd(tLinkTable*head,char * cmd){tDataNode* p=(tDataNode*)GetHeadNode(head);while(p!=NULL){if(strcmp(p->cmd,cmd)==0)return p;p=(tDataNode*)GetNextNode(head,(tLinkNode*)p);}return NULL;}int ShowAllCmd(tLinkTable* head){tDataNode* p=(tDataNode*)GetHeadNode(head);printf("Menu list:\n");while(p!=NULL){printf("%s-%s\n",p->cmd,p->desc);p=(tDataNode*)GetNextNode(head,(tLinkNode*)p);}return 0;}

接下来贴出main文件：

#include <string.h>#include "linklist.h"#include "linktable.h"#define CMD_MAX_LEN 128void mathDemo();void dogBark();void help();void quit();int Initmenu(tLinkTable ** pLinkTable);tDataNode * FindCmd(tLinkTable * head,char *cmd);int ShowAllCmd(tLinkTable* head);tLinkTable* head=NULL;int main(){char cmd[CMD_MAX_LEN];Initmenu(&head);printf("ATTENTION: input 'help' you can get all commands!\n");while(1){printf("please input a command-->");scanf("%s",cmd);tDataNode *p=FindCmd(head,cmd);if(p==NULL){printf("this is a wrong cmd!\n");continue;}printf("command:%s  description:%s\n",p->cmd,p->desc);if(p->handler != NULL){p->handler();printf("==================================\n");}}return 0;}int Initmenu(tLinkTable ** pLinkTable){*pLinkTable=CreateLinkTable();tDataNode* pNode=(tDataNode*)malloc(sizeof(tDataNode));pNode->cmd="help";pNode->desc="this is help command";pNode->handler=help;AddLinkNode(*pLinkTable,(tLinkNode*)pNode);pNode=(tDataNode*)malloc(sizeof(tDataNode));pNode->cmd="mathDemo";pNode->desc="this is math command";pNode->handler=mathDemo;AddLinkNode(*pLinkTable,(tLinkNode*)pNode);pNode=(tDataNode*)malloc(sizeof(tDataNode));pNode->cmd="quit";pNode->desc="This is quit cmd";pNode->handler=quit;AddLinkNode(*pLinkTable,(tLinkNode*)pNode);pNode=(tDataNode*)malloc(sizeof(tDataNode));pNode->cmd="dogBark";pNode->desc="This is a dog";pNode->handler=dogBark;AddLinkNode(*pLinkTable,(tLinkNode*)pNode);return 0;}void mathDemo(){printf("1 + 2 = %d\n",1+2);}void dogBark(){printf("Ruff!,RUff!,Ruff....!\n");}void help(){ShowAllCmd(head);}void quit(){printf("are you sure ? Y/N\t");char flag;scanf("%s",&flag);if(flag=='Y'||flag == 'y'){exit(0);}else{return ;}}