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 ;}}