#include "commen.h"
void echo(int clientfd);
int main()
{
signal(SIGCHLD, SIG_IGN);
int listenfd = socket(AF_INET, SOCK_STREAM, 0);
if (listenfd == -1)
err_exit("socket error");
int on = 1;
if (setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,
&on,sizeof(on)) == -1)
err_exit("setsockopt SO_REUSEADDR error");
struct sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_port = htons(8001);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(listenfd, (const struct sockaddr *)&addr, sizeof(addr)) == -1)
err_exit("bind error");
if (listen(listenfd, SOMAXCONN) == -1)
err_exit("listen error");
struct sockaddr_in clientAddr;
//谨记: 此处一定要初始化
socklen_t addrLen = sizeof(clientAddr);
while (true)
{
int clientfd = accept(listenfd, (struct sockaddr *)&clientAddr, &addrLen);
if (clientfd == -1)
err_exit("accept error");
//打印客户IP地址与端口号
cout << "Client information: " << inet_ntoa(clientAddr.sin_addr)
<< ", " << ntohs(clientAddr.sin_port) << endl;
pid_t pid = fork();
if (pid == -1)
err_exit("fork error");
else if (pid > 0)
close(clientfd);
//子进程处理链接
else if (pid == 0)
{
close(listenfd);
echo(clientfd);
close(clientfd);
//子进程一定要exit, 否则的话, 该子进程也会回到accept处
exit(EXIT_SUCCESS);
}
}
close(listenfd);
}
void echo(int clientfd)
{
struct Packet buf;
int readBytes;
//首先读取首部
while ((readBytes = readn(clientfd, &buf.msgLen, sizeof(buf.msgLen))) > 0)
{
//网络字节序 -> 主机字节序
int lenHost = ntohl(buf.msgLen);
//然后读取数据部分
readBytes = readn(clientfd, buf.text, lenHost);
if (readBytes == -1)
err_exit("readn socket error");
else if (readBytes != lenHost)
{
cerr << "client connect closed..." << endl;
return ;
}
cout << buf.text;
//然后将其回写回socket
if (writen(clientfd, &buf, sizeof(buf.msgLen)+lenHost) == -1)
err_exit("write socket error");
memset(&buf, 0, sizeof(buf));
}
if (readBytes == -1)
err_exit("read socket error");
else if (readBytes != sizeof(buf.msgLen))
cerr << "client connect closed..." << endl;
}
