蓝桥ROS机器人之现代C++学习笔记 第6章正则表达式习题

完全不会做，只能记录一下了。

---

CXX = g++
EXEC_HTTP = server.http
EXEC_HTTPS = server.https

SOURCE_HTTP = main.http.cpp
SOURCE_HTTPS = main.https.cpp

OBJECTS_HTTP = main.http.o
OBJECTS_HTTPS =  main.https.o

LDFLAGS_COMMON = -std=c++2a -O3 -pthread -lboost_system
LDFLAGS_HTTP =
LDFLAGS_HTTPS = -lssl -lcrypto

LPATH_COMMON = -I/usr/include/boost
LPATH_HTTP =
LPATH_HTTPS = -I/usr/local/opt/openssl/include

LLIB_COMMON = -L/usr/lib
LLIB_HTTPS = -L/usr/local/opt/openssl/lib

all:
	make http
	make https

http:
	$(CXX) $(SOURCE_HTTP) $(LDFLAGS_COMMON) $(LDFLAGS_HTTP) $(LPATH_COMMON) $(LPATH_HTTP) $(LLIB_COMMON) $(LLIB_HTTP) -o $(EXEC_HTTP)
https:
	$(CXX) $(SOURCE_HTTPS) $(LDFLAGS_COMMON) $(LDFLAGS_HTTPS) $(LPATH_COMMON) $(LPATH_HTTPS) $(LLIB_COMMON) $(LLIB_HTTPS) -o $(EXEC_HTTPS)

clean:
	rm -f $(EXEC_HTTP) $(EXEC_HTTPS) *.o

修改2a为17。

shiyanlou:Code/ $ unzip 6.zip                                        [21:48:31]
Archive:  6.zip
  inflating: 6/handler.hpp           
  inflating: 6/main.http.cpp         
  inflating: 6/main.https.cpp        
  inflating: 6/Makefile              
  inflating: 6/server.base.hpp       
  inflating: 6/server.http.hpp       
  inflating: 6/server.https.hpp      
   creating: 6/www/
  inflating: 6/www/index.html        
  inflating: 6/www/test.html         
shiyanlou:Code/ $ cd 6                                               [21:48:35]
shiyanlou:6/ $ make                                                  [21:50:39]
make http
make[1]: Entering directory '/home/shiyanlou/Code/6'
g++ main.http.cpp -std=c++17 -O3 -pthread -lboost_system  -I/usr/include/boost  -L/usr/lib  -o server.http
make[1]: Leaving directory '/home/shiyanlou/Code/6'
make https
make[1]: Entering directory '/home/shiyanlou/Code/6'
g++ main.https.cpp -std=c++17 -O3 -pthread -lboost_system -lssl -lcrypto -I/usr/include/boost -I/usr/local/opt/openssl/include -L/usr/lib -L/usr/local/opt/openssl/lib -o server.https
make[1]: Leaving directory '/home/shiyanlou/Code/6'
shiyanlou:6/ $                                                       [21:50:56]

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效果如下：

http

稍作修改： 

 

---

 

 

正则表达式本身，然后根据使用正则表达式的主要需求，通过一个实际的例子介绍了正则表达式库的使用。

习题

1. 在 Web 服务器开发中，我们通常希望服务某些满足某个条件的路由。正则表达式便是完成这一目标的工具之一。

给定如下请求结构：

struct Request {
    // request method, POST, GET; path; HTTP version
    std::string method, path, http_version;
    // use smart pointer for reference counting of content
    std::shared_ptr content;
    // hash container, key-value dict
    std::unordered_map header;
    // use regular expression for path match
    std::smatch path_match;
};

请求的资源类型：

typedef std::map<
    std::string, std::unordered_map<
        std::string,std::function>> resource_type;

以及服务端模板：

template 
class ServerBase {
public:
    resource_type resource;
    resource_type default_resource;
​
    void start() {
        // TODO
    }
protected:
    Request parse_request(std::istream& stream) const {
        // TODO
    }
}

请实现成员函数 start() 与 parse_request。使得服务器模板使用者可以如下指定路由：

template
void start_server(SERVER_TYPE &server) {
​
    // process GET request for /match/[digit+numbers], e.g. GET request is /match/abc123, will return abc123
    server.resource["fill_your_reg_ex"]["GET"] = [](ostream& response, Request& request) {
        string number=request.path_match[1];
        response << "HTTP/1.1 200 OK\r\nContent-Length: " << number.length() << "\r\n\r\n" << number;
    };
​
    // peocess default GET request; anonymous function will be called if no other matches
    // response files in folder web/
    // default: index.html
    server.default_resource["fill_your_reg_ex"]["GET"] = [](ostream& response, Request& request) {
        string filename = "www/";
​
        string path = request.path_match[1];
​
        // forbidden use `..` access content outside folder web/
        size_t last_pos = path.rfind(".");
        size_t current_pos = 0;
        size_t pos;
        while((pos=path.find('.', current_pos)) != string::npos && pos != last_pos) {
            current_pos = pos;
            path.erase(pos, 1);
            last_pos--;
        }
​
        // (...)
    };
​
    server.start();
}

参考原作者答案。

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