Linux插件框架实验报告.doc
,电 子 科 技 大 学实 验 报 告学生姓名： 学 号： 指导教师：实验地点：A2-412 实验时间：2012.01.04一、实验室名称：Linux环境高级编程实验室二、实验项目名称：插件框架实验三、实验学时：4学时四、实验目的：学习和实践插件框架的开发。理解插件的工作原理，为进一步开发高可用，高复杂度的插件打下基础。五、实验内容：1、使用动态链接库实现打印功能：开发一个程序，向屏幕打印“Hello World”；在不重新编译链接原程序的前提下，将打印的文字改为“Hello China”。2、使用动态链接库实现自定义打印功能：同时要打印“Hello World”，打印“Hello China”，甚至同时打印未来才会增加的其他打印信息，打印信息的链接库放在一个固定目录中，遍历这个目录，获取所有动态链接库。打印未来的这些信息，也不能重新编译链接原程序。3、1）通过命令行方式：./a.out help，输出所有插件实现的功能ID，以及该功能ID对应的功能描述。2）通过命令行方式：./a.out FuncID，调用具体打印功能（每个插件导出GetID接口）。4、将插件导出的Print、GetID、Help三个函数放在一个类中，主程序需要使用多个容器分别保存这些函数地址，让插件外部获取该类的对象。综合练习：实现一个软件系统，该系统可对文件进行统计分析。究竟对文件进行什么样的统计分析，最终用户自己也不是很清楚，目前只知道需要统计文件的行数。也就是说，本软件系统将会随时面临，增加文件统计新功能的难题。请结合本实验内容，设计并实现这样一个面向文件统计功能的插件系统。（需要实现的插件包括：统计某个文件的行数，统计某个文件的字节数）六、实验步骤：程序1：A. h:extern "c" void f();a2.cpp：#include<iostream>#include"a.h"using namespace std;void f() cout << "hello,China!" << endl;A1.cpp:#include<iostream>#include"a.h"using namespace std;void f() cout << "Hello,Word" << endl;Main.cpp:#include"a.h"#include<dlfcn.h>#include<iostream>using namespace std;int main() void *handle = dlopen("./libtest.so", RTLD_LAZY); if(0 = handle) cout << "dlopen error" << endl;return 0; typedef void (*Fun)(); Fun f1 = (Fun)dlsym(handle, "f"); if(0 = f1) cout << "f1 error" << endl; char *str = dlerror();cout << str << endl; (*f1)(); dlclose(handle); return 0;程序运行结果如图1所示：图1：字符的变换程序2：A1.cpp:#include<iostream>using namespace std;extern"C" void f()cout << "Hello world" << endl;A2.cpp:#include<iostream>using namespace std;extern "C" void f() cout << "Hello,china!" << endl;A3.cpp:#include<iostream>using namespace std;extern "C" void f()cout << "Hello 333" << endl;A4.cpp:#include<iostream>using namespace std;extern "C" void f()cout << "Hello 4444" << endl;Test2.cpp:#include<dlfcn.h>#include<iostream>#include<dirent.h>#include<stdio.h>#include<string.h>using namespace std;int main()char path260;DIR *dir;struct dirent *ptr; dir=opendir("/root/test/test4/plug2/plugin/");while(ptr=readdir(dir)!=NULL)if (strcmp(ptr->d_name,".")=0)|(strcmp(ptr->d_name,".")=0)continue;sprintf(path,"/root/test/test4/plug2/plugin/%s", ptr->d_name); void *handle = dlopen(path, RTLD_LAZY); if(0 = handle) cout << "dlopen error" << endl;return 0; typedef void (*Fun)(); Fun pf = (Fun)dlsym(handle, "f"); if(0 = pf) cout << "pf error" << endl; char *str = dlerror();cout << str << endl;return 0; (*pf)();dlclose(handle); closedir(dir);程序运行结果如图2所示：图2：插件的遍历程序3：a1.cpp:#include <iostream>using namespace std;const int FUNC_ID = 1;extern "C" void f() cout << "Hello World!" << endl;extern "C" void Help() cout << "Function ID " << FUNC_ID << " : This function prints Hello World." << endl;a2.cpp:#include <iostream>using namespace std;const int FUNC_ID = 2;extern "C" void f() cout << "Hello China!" << endl;extern "C" void Help() cout << "Function ID " << FUNC_ID << " This function prints hello china." << endl;CPluginEnumerator.cpp#include "CPluginEnumerator.h"#include <dirent.h>#include <string.h>#include <iostream>#include <stdio.h>CPluginEnumerator:CPluginEnumerator()CPluginEnumerator:CPluginEnumerator()bool CPluginEnumerator:GetPluginNames(vector<string>& vstrPluginNames) DIR *dir = opendir("/root/test/test4/plug3/plugin"); if(dir = 0)return false; for(;) struct dirent *ptr = readdir(dir);if(ptr = 0)break;if(strcmp(ptr->d_name, ".") = 0)|(strcmp(ptr->d_name, ".") = 0)continue;char path260;sprintf(path, "/root/test/test4/plug3/plugin/%s", ptr->d_name);vstrPluginNames.push_back(path); closedir(dir);return true;Test.cpp:#include <dlfcn.h>#include <iostream>#include "CPluginEnumerator.h"#include <string.h>#include <stdio.h>using namespace std;int main(int argc, char *argv)char path 260; if(argc != 2)return 0; if(strcmp(argv1, "help") = 0) vector<string> vstrPluginNames; CPluginEnumerator enumerator; if(!enumerator.GetPluginNames(vstrPluginNames) cout << "GetPluginNames error" << endl;return 0; for(int i = 0; i< vstrPluginNames.size(); i+) void *handle = dlopen(vstrPluginNamesi.c_str(), RTLD_LAZY);if(handle = 0)cout << "dlopen error" << endl; return 0;typedef void (*FUNC_HELP)();FUNC_HELP dl_help = (FUNC_HELP)dlsym(handle, "Help");if(dl_help = 0)cout << "dlsym error" << endl; return 0;(dl_help)();dlclose(handle);else if(strcmp(argv1, "1") = 0)sprintf(path, "/root/test/test4/plug3/plugin/%s", "a1.so");void *handle = dlopen(path, RTLD_LAZY);if(handle = 0)cout << "dlopen error" << endl;return 0;typedef void (*FUNC_PRINT)();FUNC_PRINT dl_print = (FUNC_PRINT)dlsym(handle, "f");if(dl_print = 0)cout << "dlsym error" << endl;return 0;(dl_print)();dlclose(handle);else if(strcmp(argv1, "2") = 0)/ 得到第二个func的参数sprintf(path, "/root/test/test4/plug3/plugin/%s", "a2.so");void *handle = dlopen(path, RTLD_LAZY);if(handle = 0)cout << "dlopen error" << endl;return 0;typedef void (*FUNC_PRINT)();FUNC_PRINT dl_print = (FUNC_PRINT)dlsym(handle, "f");if(dl_print = 0)cout << "dlsym error" << endl;return 0;(dl_print)();dlclose(handle);return 0;程序运行结果如图3所示：图3：插件输出程序4：CPluginEnumerator.h:#ifndef CPLUGINENUMERATOR_H#define CPLUGINENUMERATOR_H#include <vector>#include <string>using namespace std;class CPluginEnumeratorpublic: CPluginEnumerator(); virtual CPluginEnumerator(); bool GetPluginNames(vector<string>& vstrPluginNames);#endifCPluginEnumerator.cpp：#include "CPluginEnumerator.h"#include <dirent.h>#include <string.h>CPluginEnumerator:CPluginEnumerator()CPluginEnumerator:CPluginEnumerator()bool CPluginEnumerator:GetPluginNames(vector<string>& vstrPluginNames) DIR *dir = opendir("./plugin"); if(dir = 0)return false; for(;) struct dirent *pentry = readdir(dir);if(pentry = 0) break;if(strcmp(pentry->d_name, ".") = 0) continue;if(strcmp(pentry->d_name, ".") = 0) continue;string str = "./plugin/"str += pentry->d_name;vstrPluginNames.push_back(str); closedir(dir); return true;CPluginController.h#ifndef CPLUGINCONTROLLER_H#define CPLUGINCONTROLLER_H#include <vector>class IPrintPlugin;class CPluginControllerpublic:CPluginController(void);virtual CPluginController(void);bool InitializeController(void);bool UninitializeController(void);bool ProcessHelp(void);bool ProcessRequest(int FunctionID);private:std:vector<void *> m_vhForPlugin;std:vector<IPrintPlugin*> m_vpPlugin;#endifCPluginController.cpp#include "CPluginController.h"#include "CPluginEnumerator.h"#include "IPrintPlugin.h"#include "dlfcn.h"CPluginController:CPluginController(void)CPluginController:CPluginController(void)bool CPluginController:InitializeController(void)std:vector<std:string> vstrPluginNames;CPluginEnumerator enumerator;if(!enumerator.GetPluginNames(vstrPluginNames)return false;for(unsigned int i=0 ; i<vstrPluginNames.size(); i+)typedef int (*PLUGIN_CREATE)(IPrintPlugin*);PLUGIN_CREATE CreateProc; IPrintPlugin *pPlugin = NULL;void* hinstLib = dlopen(vstrPluginNamesi.c_str(), RTLD_LAZY); if(hinstLib != NULL) m_vhForPlugin.push_back(hinstLib);CreateProc = (PLUGIN_CREATE)dlsym(hinstLib, "CreateObj"); if(NULL != CreateProc) (CreateProc)(&pPlugin);if(pPlugin != NULL)m_vpPlugin.push_back(pPlugin);return true;bool CPluginController:ProcessRequest(int FunctionID)for(unsigned int i = 0; i < m_vpPlugin.size(); i+)if(m_vpPlugini->GetID() = FunctionID)m_vpPlugini->Print();break;return true;bool CPluginController:ProcessHelp(void)std:vector<std:string> vstrPluginNames;CPluginEnumerator enumerator;if(!enumerator.GetPluginNames(vstrPluginNames)return false;for(unsigned int i=0 ; i<vstrPluginNames.size(); i+)typedef int (*PLUGIN_CREATE)(IPrintPlugin*);PLUGIN_CREATE CreateProc; IPrintPlugin *pPlugin = NULL;void* hinstLib = dlopen(vstrPluginNamesi.c_str(), RTLD_LAZY); if(hinstLib != NULL) CreateProc = (PLUGIN_CREATE)dlsym(hinstLib, "CreateObj"); if(NULL != CreateProc) (CreateProc)(&pPlugin);if(pPlugin != NULL)pPlugin->Help();dlclose(hinstLib);return true;bool CPluginController:UninitializeController()for(unsigned int i = 0; i < m_vhForPlugin.size(); i+)dlclose(m_vhForPlugini);return true;IPrintPlugin.h#pragma onceclass IPrintPluginpublic:IPrintPlugin();virtual IPrintPlugin();virtual void Help() = 0;virtual void Print() = 0;virtual int GetID() = 0;IPrintPlugin.cpp#include "IPrintPlugin.h"IPrintPlugin:IPrintPlugin()IPrintPlugin:IPrintPlugin()Function.cpp#include <iostream>#include "IPrintPlugin.h"using namespace std;const int FUNC_ID = 1;class CPrintPlugin : public IPrintPluginpublic:CPrintPlugin()virtual CPrintPlugin()virtual void Print()cout << "Hello World!" << endl;virtual void Help()cout << "Function ID " << FUNC_ID << " : This function will print hello world." << endl;virtual int GetID(void)return FUNC_ID;extern "C" void CreateObj(IPrintPlugin *ppPlugin)static CPrintPlugin plugin;*ppPlugin = &plugin;function1.cpp#include <iostream>#include "IPrintPlugin.h"using namespace std;const int FUNC_ID = 2;class CPrintPlugin : public IPrintPluginpublic:CPrintPlugin()virtual CPrintPlugin()virtual void Print()cout << "Hello China!" << endl;virtual void Help()cout << "Function ID " << FUNC_ID << " : This function will print hello china." << endl;virtual int GetID(void)return FUNC_ID;extern "C" void CreateObj(IPrintPlugin *ppPlugin)static CPrintPlugin plugin;*ppPlugin = &plugin;Main.cpp#include <iostream>#include "CPluginController.h"#include <string.h>#include <stdlib.h>using namespace std;int main(int argc, char *argv)if(argc != 2)cout << "Parameters error" << endl;return 0;if(strcmp(argv1, "help") = 0)CPluginController pc;pc.ProcessHelp();return 0;int FunctionID = atoi(argv1);CPluginController pc;pc.InitializeController();pc.ProcessRequest(FunctionID);pc.UninitializeController();return 0;程序运行结果如图4所示：图4：插件获取类对象综合练习：CPluginController.cpp#include "CPluginController.h"#include "CPluginEnumerator.h"#include "IPrintPlugin.h"#include "dlfcn.h"#include <string.h>CPluginController:CPluginController(void)CPluginController:CPluginController(void)bool CPluginController:InitializeController(void)std:vector<std:string> vstrPluginNames;CPluginEnumerator enumerator;if(!enumerator.GetPluginNames(vstrPluginNames)return false;for(unsigned int i=0 ; i<vstrPluginNames.size(); i+)typedef int (*PLUGIN_CREATE)(IPrintPlugin*);PLUGIN_CREATE CreateProc; IPrintPlugin *pPlugin = NULL;void* hinstLib = dlopen(vstrPluginNamesi.c_str(), RTLD_LAZY); if(hinstLib != NULL) m_vhForPlugin.push_back(hinstLib);CreateProc = (PLUGIN_CREATE)dlsym(hinstLib, "CreateObj"); if(NULL != CreateProc) (CreateProc)(&pPlugin);if(pPlugin != NULL)m_vpPlugin.push_back(pPlugin);return true;bool CPluginController:ProcessRequest(int FunctionID)for(unsigned int i = 0; i < m_vpPlugin.size(); i+)if(m_vpPlugini->GetID() = FunctionID)m_vpPlugini->Print();break;return true;bool CPluginController:ProcessHelp(void)std:vector<std:string> vstrPluginNames;CPluginEnumerator enumerator;if(!enumerator.GetPluginNames(vstrPluginNames)return false;for(unsigned int i=0 ; i<vstrPluginNames.size(); i+)typedef int (*PLUGIN_CREATE)(IPrintPlugin*);PLUGIN_CREATE CreateProc; IPrintPlugin *pPlugin = NULL;void* hinstLib = dlopen(vstrPluginNamesi.c_str(), RTLD_LAZY); if(hinstLib != NULL) CreateProc = (PLUGIN_CREATE)dlsym(hinstLib, "CreateObj"); if(NULL != CreateProc) (CreateProc)(&pPlugin);if(pPlugin != NULL)pPlugin->Help();dlclose(hinstLib);return true;bool CPluginController:IfProcess(char *Function)/判断插件是否存在unsigned int i;for(i = 0; i < m_vpPlugin.size(); i+)if(strcmp(Function, m_vpPlugini->GetName() = 0)break;if(i < m_vpPlugin.size()/插件存在return true;elsereturn false;bool CPluginController:ProcessFunction(char *Function,char*Document)/执行插件功能for(unsigned int i = 0; i < m_vpPlugin.size(); i+)if(strcmp(Function, m_vpPlugini->GetName() = 0)m_vpPlugini->Fun(Document);/插件功能break;return true;bool CPluginController:UninitializeController()for(unsigned int i = 0; i < m_vhForPlugin.size(); i+)dlclose(m_vhForPlugini);return true;CPluginController.h#ifndef CPLUGINCONTROLLER_H#define CPLUGINCONTROLLER_H#include <vector>class IPrintPlugin;class CPluginControllerpublic:CPluginController(void);virtual CPluginController(void);bool InitializeController(void);bool UninitializeController(void);bool ProcessHelp(void);bool ProcessRequest(int FunctionID);bool IfProcess(char *Function);bool ProcessFunction(char *Function,char
