基于UDP的回声服务端/客户端

学习记录 系统：linux 语言：c语言 UDP不存在请求连接与受理过程 github 地址 github.com/skrura/tcp-…

uecho_server.c

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

#define BUF_SIZE 30
void error_handling(char *message);

int main(int argc,char *argv[])
{
	int serv_sock;
	char message[BUF_SIZE];
	int str_len;
	socklen_t clnt_adr_sz;
	struct sockaddr_in serv_adr,clnt_adr;
	if(argc!=2)
	{
		printf("Usage : %s <port>\n",argv[0]);
		exit(1);
	}

	serv_sock=socket(PF_INET,SOCK_DGRAM,0);
	if(serv_sock == -1)
		error_handling("UDP socket creation 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");
	while(1)
	{
		clnt_adr_sz=sizeof(clnt_adr);
		str_len=recvfrom(serv_sock,message,BUF_SIZE,0,(struct sockaddr*)&clnt_adr,&clnt_adr_sz);
		sendto(serv_sock,message,str_len,0,(struct sockaddr*)&clnt_adr,clnt_adr_sz);
	}
	close(serv_sock);
	return 0;
}
void error_handling(char *message)
{
	fputs(message,stderr);
	fputc('\n',stderr);
	exit(1);
}

uecho_client.c

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

#define BUF_SIZE 30
void error_handling(char *message);

int main(int argc,char *argv[])
{
	int sock;
	char message[BUF_SIZE];
	int str_len;
	socklen_t adr_sz;
	
	struct sockaddr_in serv_adr,from_adr;
	if(argc!=3)
	{
		printf("Usage : %s <IP> <port>\n",argv[0]);
		exit(1);
	}
	
	sock=socket(PF_INET,SOCK_DGRAM,0);
	if(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=inet_addr(argv[1]);
	serv_adr.sin_port=htons(atoi(argv[2]));
	
	while(1)
	{
		fputs("Insert message(q to quit):",stdout);
		fgets(message,sizeof(message),stdin);
		if(!strcmp(message,"q\n")||!strcmp(message,"Q\n"))
			break;
		
		sendto(sock,message,strlen(message),0,(struct sockaddr*)&serv_adr,sizeof(serv_adr));
		adr_sz=sizeof(from_adr);
		str_len=recvfrom(sock,message,BUF_SIZE,0,(struct sockaddr*)&from_adr,&adr_sz);
		message[str_len]=0;
		printf("Message from server: %s",message);
	}
	close(sock);
        return 0;

}


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