#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/time.h>

int main(int argc, char * argv [])
{	
/*		1. getaddrinfo		
		2. create a new socket		
		3. connect to the socket		
		4. send data	*/			
		//Variables Declaration	
		struct addrinfo hints, * res;	
		int status;	int socket_id;		
		//clear hints	
		memset(&hints, 0, sizeof hints);	
		hints.ai_family = AF_UNSPEC;	
		hints.ai_socktype = SOCK_STREAM;	
		hints.ai_flags = AI_PASSIVE;
		char sever_ip_default[100]="127.0.0.1";
		char sever_port_default[100]="6666";
		char * p_sever_ip = NULL;
		char * p_sever_port = NULL;

		if(argc>=2)
			p_sever_ip = argv[1];
		else
			p_sever_ip = sever_ip_default;
		if(argc>= 3)
			p_sever_port = argv[2];
		else
			p_sever_port = sever_port_default;
			

		printf("Sever ip is %s	and port is %s\n",p_sever_ip,p_sever_port);
		//status = getaddrinfo("127.0.0.1","6666", &hints, &res);	
		status = getaddrinfo(p_sever_ip,p_sever_port, &hints, &res);	

		if(status != 0)	
		{		
			fprintf(stderr, "Error getaddrinfo\n");		
			exit(1);	
		}	 			
		socket_id = socket(res->ai_family, res->ai_socktype, res->ai_protocol);	
		if(socket_id < 0)	
		{		
			fprintf(stderr, "Error socket \n");		
			exit(2);	
		}		
		struct timeval tv_begin, tv_end, tv_value;
		gettimeofday(&tv_begin, NULL);
		status = connect(socket_id, res->ai_addr, res->ai_addrlen);	
		gettimeofday(&tv_end, NULL);
		tv_value.tv_sec =  tv_end.tv_sec - tv_begin.tv_sec;
		tv_value.tv_usec = tv_end.tv_usec - tv_begin.tv_usec;
		printf("connect time:%lds and %ldus\n",tv_value.tv_sec,tv_value.tv_usec);
		
		if(status < 0)	
		{		
			fprintf(stderr, "Error connect \n");		
			exit(3);	
		}		
		int numbytes = 0;	
		char buf[10];	
		numbytes = recv(socket_id,buf,10,0);	
		if(numbytes == -1)	
		{		
			fprintf(stderr, "Error receive \n");		
			exit(4);	
		}	
		buf[numbytes] = '\0';	
		printf("Received %s \n", buf);		
		freeaddrinfo(res);	
		close(socket_id);		
		return 0;
}

 

參考連結：http://code.runnable.com/VXjZAA1cltc0LP9r/simple-tcp-client-code-for-c%2B%2B-and-socket