Linux socket编程（一）对套接字操作的封装

转载:http://www.cnblogs.com/-Lei/archive/2012/09/04/2670942.html

以前写的，现在回顾一下：

下面是对socket操作的封装，因为在Linux下写中文到了windows里面会乱码，所以注释用英文来写，有空再查下解决方法吧

socket.h

#ifndef SOCKET_H
#define SOCKET_H#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string>const int MAXCONNECTION=5;
const int MAXRECEIVE = 500;class Socket
{public:Socket();//virtual destructiorvirtual ~Socket();// Server initializationbool Create(); //create a socketbool Bind(const int port);bool Listen() const;bool Accept(Socket& clientSocket) const;// Client initializationbool Connect(const std::string& host,const int port);// Data Transmissionbool Send(Socket& socket,const std::string& message) const;int Receive(Socket& socket,std::string& message) const;void SetNonBlocking(const bool flag);bool IsValid() const;private://use m_sockfd to record the result of function socketint m_sockfd;struct sockaddr_in m_address;
};#endif

这里解释下为什么析构函数是虚的，如果要用到多态的话，也就是用一个指向基类的指针来处理对不同到对象

如果类的成员函数不是虚函数，只是个普通的函数，那么会出现一种静态绑定到情况，如

Base* pBase = new Derive; //这里Base的析构函数不是虚函数

delete pBase; //这里只会调用Base::~Base()，所以派生类部分的资源将得不到释放

如果析构函数是虚函数的话，那么将调用Derive::~Derive()，由于我们提供了派生类的析构函数，编译器会扩展这个析构函数，

在里面调用基类的析构函数，这样派生类和基类的资源都将得到释放

socket.cpp

#include "Socket.h"
#include <stdlib.h>
#include <memory.h>
#include <iostream>
#include <fcntl.h>Socket::Socket()
:m_sockfd(-1)
{
}Socket::~Socket()
{if(IsValid())::close(m_sockfd);
}//server function
bool Socket::Create()
{m_sockfd=socket(AF_INET,SOCK_STREAM,0);if(!IsValid())return false;return true;
}bool Socket::Bind(const int port)
{if(!IsValid())return false;m_address.sin_family=AF_INET;m_address.sin_addr.s_addr = htonl(INADDR_ANY);m_address.sin_port=htons(port);int bindReturn=bind(m_sockfd,(struct sockaddr*)&m_address,sizeof(m_address));if(bindReturn==-1)return false;return true;
}bool Socket::Listen()const
{if(!IsValid())return false;int listenReturn=listen(m_sockfd,MAXCONNECTION);if(listenReturn ==-1)return false;return true;
}bool Socket::Accept(Socket& clientSocket) const
{int clientaddrLength=sizeof(clientSocket.m_address);clientSocket.m_sockfd=::accept(m_sockfd,(struct sockaddr*)&clientSocket.m_address,(socklen_t *)&clientaddrLength);if(clientSocket.m_sockfd==-1)return false;return true;
}
//end server functionsbool Socket::Connect(const std::string& host,const int port)
{if(!IsValid())return false;m_address.sin_family=AF_INET;m_address.sin_port=htons(port);m_address.sin_addr.s_addr=inet_addr(host.c_str());int connectReturn=::connect(m_sockfd,(struct sockaddr*)&m_address,sizeof(m_address));if(connectReturn==-1)return false;return true;}// Data Transmission
bool Socket::Send(Socket& socket,const std::string& message) const
{int result=::send(socket.m_sockfd,message.c_str(),message.length(),MSG_NOSIGNAL);if(result==-1)return false;return true;
}int Socket::Receive(Socket& socket,std::string& message) const
{char buffer[MAXRECEIVE+1];message.clear();memset(buffer,0,MAXRECEIVE+1);int numberRead=::recv(socket.m_sockfd,buffer,MAXRECEIVE,0);if(numberRead==-1){std::cout<<"error in Socket::Receive\n";return 0;}else if(numberRead==0)return 0;else{message=buffer;return numberRead;}}void Socket::SetNonBlocking(const bool flag)
{if(IsValid())
    {
          int opts;

          opts = fcntl ( m_sockfd,
                 F_GETFL );

          if ( opts < 0 )
            {
              return;
            }

          if ( flag )
            opts = ( opts | O_NONBLOCK );
          else
            opts = ( opts & ~O_NONBLOCK );

          fcntl ( m_sockfd,
              F_SETFL,opts );

    }
}bool Socket::IsValid() const
{//if call function socket fail,it returns -1return m_sockfd!=-1;
}

接下来是异常处理到类

#ifndef SocketException_H
#define SocketException_H#include <string>class SocketException
{public:SocketException ( std::string description ) : m_description( description ) {};~SocketException (){};std::string Description() { return m_description; }private:std::string m_description;
};#endif