client1.c

这个是linux下

	#include <stdio.h> 
	#include <unistd.h>
	#include <strings.h>
	#include <sys/types.h> 
	#include <sys/socket.h> 
	#include <netinet/in.h> 
	#include <netdb.h>        /* netbd.h is needed for struct hostent  */ 

	#define PORT 1234   /* Open Port on Remote Host */ 
	#define MAXDATASIZE 1024 /* Max number of bytes of data */ 

	int main(int argc, char *argv[]) 
	{ 
	int fd, numbytes;   /* files descriptors */ 
	char recvbuf[MAXDATASIZE];  /* buf will store received text */ 
	char sendbuf[MAXDATASIZE];
        char cliname[100];
	struct hostent *he;         /* structure that will get information about remote host */ 
	struct sockaddr_in server;  /* server's address information */ 
	const char condition[]="quit\n";

	if (argc !=2) {       /* this is used because our program will need one argument (IP) */ 
	printf("Usage: %s <IP Address>\n",argv[0]); 
	exit(1); 
	} 

	if ((he=gethostbyname(argv[1]))==NULL){ /* calls gethostbyname() */ 
	printf("gethostbyname() error\n"); 
	exit(1); 
	} 

	if ((fd=socket(AF_INET, SOCK_STREAM, 0))==-1){  /* calls socket() */ 
	printf("socket() error\n"); 
	exit(1); 
	} 

	bzero(&server,sizeof(server));
	server.sin_family = AF_INET; 
	server.sin_port = htons(PORT); /* htons() is needed again */ 
	server.sin_addr = *((struct in_addr *)he->h_addr);  /*he->h_addr passes "*he"'s info to "h_addr" */ 


	if(connect(fd, (struct sockaddr *)&server,sizeof(struct sockaddr))==-1){ /* calls connect() */ 
	printf("connect() error\n"); 
	exit(1); 
	} 
	
                
	  	printf("input your name:");

                fgets(cliname,100,stdin);
	/*	getchar();*/
	if ((numbytes=send(fd,cliname,strlen(cliname),0)) == -1){  /* calls recv() */
	     printf("send() error\n");
		exit(0);
		}
while(1)	
	{
	     /*fflush(stdin);*/
                bzero(&sendbuf,strlen(sendbuf));
		printf("input message:");
         	fgets(sendbuf,MAXDATASIZE,stdin);
	/*	getchar();*/
    		if(strcmp(sendbuf,condition)==0) 
    		{
    			exit(1);
    		}

         if ((numbytes=send(fd,sendbuf,strlen(sendbuf),0)) == -1){  /* calls recv() */
             printf("send() error\n");
            exit(1);
           }
	     bzero(&recvbuf,sizeof(recvbuf));
		if ((numbytes=recv(fd,recvbuf,MAXDATASIZE,0)) == -1){  /* calls recv() */ 
		printf("recv() error\n"); 
		exit(1); 
		} 

		recvbuf[numbytes]='\0'; 
	 printf("Server Message: %s\n",recvbuf);/*it prints server's welcome message  */ 
 

        }

	close(fd);   /* close fd */ 
	

}