udp_server.c

linux下简单的UDP传输文件功能

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 1234
#define MAXDATASIZE 100

main()
{
	int sockfd;
	struct sockaddr_in server,client;
	int sin_size;
	int num;
	char msg[MAXDATASIZE];
	if((sockfd = socket(AF_INET,SOCK_DGRAM,0)) == -1)
	{
		printf("create socket error.\n");
		exit(1);
	}
	bzero(&server,sizeof(server));
	server.sin_family = AF_INET;
	server.sin_port = htons(PORT);
	server.sin_addr.s_addr = htonl(INADDR_ANY);

	if(bind(sockfd,(struct sockaddr *)&server,sizeof(struct sockaddr)) == -1)
	{
		printf("bind error.\n");
		exit(1);
	}
	sin_size = sizeof(struct sockaddr_in);
	while(1){
		num = recvfrom(sockfd,msg,MAXDATASIZE,0,(struct sockaddr *)&client,&sin_size);
		if(num < 0)
		{
			printf("recvfrom error.\n");
			exit(1);

		}
		msg[num] ='\0';
		printf("You got a message (%s) from %s\n",msg,inet_ntoa(client.sin_addr));
		sendto(sockfd,"Welcome to my server.\n",22,0,(struct sockaddr *)&client,sin_size);
		if(!strcmp(msg,"quit")) break;
	}
	close(sockfd);
}