echoserver.cc

达内IT培训Unix C++第一天源码（共四天） 是入门Unix 下C++编程的好东西

#include <iostream>
using namespace std;
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>
#include <fcntl.h>
#include <cstring>
#include <signal.h>
#include <sys/wait.h>

void err(const char* msg)
{
	cout << msg << " error!" << endl;
	exit(-1);
}
void func(int sig)
{
	signal(sig, func);
	while(waitpid(-1,NULL,WNOHANG)>0);
}
int main()
{
	signal(SIGCHLD, func);
	short port;
	cout << "input port:";
	cin >> port;
	sockaddr_in si;
	si.sin_family = AF_INET;
	si.sin_addr.s_addr = htonl(INADDR_ANY);
	si.sin_port = htons(port);
	int s = socket(AF_INET,SOCK_STREAM,0);
	if(s<0) err("socket");
	socklen_t len=sizeof(si);
	if(bind(s, (sockaddr*)&si, len)<0)
		err("bind");
	if(listen(s, 20)<0)
		err("listen");
	for(;;){
		int c=accept(s,(sockaddr*)&si,&len);
		if(c<0) continue;
		if(fork()!=0){
			close(c);
			continue;
		}
		close(s);
		char buf[1000]="Your IP: ";
		char ip[100];
		inet_ntop(AF_INET,&si.sin_addr,ip,100);
		strcat(buf, ip);
		strcat(buf, "\n");
		cout << ip << "到此一游" << endl;
		write(c, buf, strlen(buf));
		for(;;){
			int n=read(c, buf, 1000);
			if(n<=0) break;
			if(buf[0]=='q') break;
			buf[n] = '\0';
			cout << ip << ':' << buf <<endl;
			write(c, buf, n);
		}
		close(c);
		exit(0);
	}
}