TCP/IP网络编程_echo回声服务器端与/客户端

//自己在写的时候碰到的坑

1.注意服务器端serv_adr.sin_addr.s_addr=htonl(INADDR_ANY)写成inet_addr(INADDR_ANY)就是错的
2.注意客户端serv_adr.sin_addr.s_addr=inet_addr(argv[1]);写成htonl(argv[1])就是错的
3.注意while((str_len=read(clnt_sock,message,BUF_SIZE))!=0)不要写成while(str_len=read(clnt_sock,message,BUF_SIZE)!=0)少个括号
4.1 2l两点看函数原型就知道错在哪儿了,参数类型不匹配 第3点隐蔽性很高因为即使写错了还是能通过编译 只是运行不是预期的结果 debug起来很但疼

//源码服务器端：

#include 
#include 
#include 
#include 
#include 
#include 

#define BUF_SIZE 1024
void error_handling(char *message);

int main(int argc,char *argv[])
{
	int serv_sock,clnt_sock;
	char message[BUF_SIZE];
	int str_len,i;
	
	struct sockaddr_in serv_adr,clnt_adr;
	socklen_t clnt_adr_sz;
	
	if(argc!=2)
	{
		printf("Usage : %s  \n",argv[0]);
		exit(1);
	}
	
	serv_sock=socket(PF_INET,SOCK_STREAM,0);
	if(serv_sock==-1)
		error_handling("socket() error");
	
	memset(&serv_adr,0,sizeof(serv_adr));
	serv_adr.sin_family=AF_INET;
	serv_adr.sin_addr.s_addr=htonl(INADDR_ANY);
	serv_adr.sin_port=htons(atoi(argv[1]));
	
	if(bind(serv_sock,(struct sockaddr*)&serv_adr,sizeof(serv_adr))==-1)
		error_handling("bind() error");
		
	if(listen(serv_sock,5)==-1)
		error_handling("listen() error");
	
	clnt_adr_sz=sizeof(clnt_adr);
	for(int i=0;i<5;++i)
	{
		clnt_sock=accept(serv_sock,(struct sockaddr*)&clnt_adr,&clnt_adr_sz);
		if(clnt_sock==-1)
			error_handling("accept() error");
		else
			printf("Connected client %d \n",i+1);
		
		while( (str_len=read(clnt_sock,message,BUF_SIZE) )!=0 )
			write(clnt_sock,message,str_len);
			
		close(clnt_sock);
	}
	close(serv_sock);
	return 0;
	
}

void error_handling(char *message)
{
	fputs(message,stderr);
	fputc('\n',stderr);
	exit(1);
}

//客户端源码：

#include 
#include 
#include 
#include 
#include 
#include 

void error_handling(char *message)
{
	printf("%s\n",message);
	exit(1);
}
const int MAXN=(1<<10);
int main(int argc,char *argv[])
{
	int clnt_sock;
	struct sockaddr_in serv_adr;
	char msg[MAXN];
	char store[MAXN];
	int str_len,str_cnt;
	
	if(argc!=3)
	{
		printf("Usage %s  \n",argv[0]);
		exit(1);
	}
	clnt_sock=socket(PF_INET,SOCK_STREAM,0);	//第一步
	if(clnt_sock==-1)
		error_handling("socket() error");
		
	memset(&serv_adr,0,sizeof(serv_adr));		//填写要连接的服务器端地址
	serv_adr.sin_family=AF_INET;
	serv_adr.sin_addr.s_addr=inet_addr(argv[1]);	//写成htonl(argv[1])就是错,因为htonl()函数的参数要求为unsigned long而argv[1]却是字符串
	serv_adr.sin_port=htons(atoi(argv[2]));
	
		
	if(connect(clnt_sock,(struct sockaddr*)&serv_adr,sizeof(serv_adr))==-1)		//第二步
		error_handling("connect() error");
		
	while(1)
	{
		printf("send message to server(input q/Q to exit):");
		scanf("%s",msg);
		if(!strcmp(msg,"q")||!strcmp(msg,"Q"))
			break;
		str_len=write(clnt_sock,msg,strlen(msg));
		str_cnt=0;
		while(str_cnt