client.c~

unix高级编程开发环境

/* Client.c */
#include<stdio.h>
#include<sys/types.h>
#include<stdlib.h>
#include<strings.h>
#include<unistd.h>
#include<sys/wait.h>
#include<signal.h>
#include<netdb.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>

#define PORT 4000
#define MAXDATASIZE 100

int main(int argc, char*argv[])
{
	int sockfd,numbytes;
	char buf[MAXDATASIZE];
	struct hostent* he;
	struct sockaddr_in their_addr;

	if (argc != 2)
	{
		fprintf(stderr, "usage:client hostname\n");
		exit(1);
	}

	if ((he = gethostbyname(argv[1])) == NULL)
	{
		perror("gethostbyname");
		exit(1);
	}
	their_addr.sin_family = AF_INET;
	their_addr.sin_port = htons(PORT);
	their_addr.sin_addr = *((struct in_addr*)he->h_addr);
	bzero(&(their_addr.sin_zero), 8);

	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0))== -1)
	{
		perror("socket");
		exit(1);
	}
	else
	{
		printf("socket success!\n");
	}

	if (connect(sockfd, (struct sockaddr*)&their_addr, sizeof(struct sockaddr)) == -1)
	{
		perror("connect");
		exit(1);
	}
	else
	{
		printf("connect success!\n");
	}

	if ((numbytes=recv(sockfd,buf,MAXDATASIZE,0)) == -1)
	{
		perror("recv");
		exit(1);
	}
	else
	{
		printf("recv success!\n");
	}

	buf[numbytes] = ' ';
	printf("%s",buf);

	return 0;
}