Linux 网络编程 UDP 套接字程序示例--服务器端代码如下：

/************************************************************************* 
 > File Name: server.c 
 > Author: SongLee 
 ************************************************************************/ 
#include<sys/types.h> 
#include<sys/socket.h> 
#include<unistd.h> 
#include<netinet/in.h> 
#include<arpa/inet.h> 
#include<stdio.h> 
#include<stdlib.h> 
#include<errno.h> 
#include<netdb.h> 
#include<stdarg.h> 
#include<string.h> 
 
#define SERVER_PORT 8000 
#define BUFFER_SIZE 1024 
#define FILE_NAME_MAX_SIZE 512 
 
int main() 
{ 
 /* 创建UDP套接口 */ 
 struct sockaddr_in server_addr; 
 bzero(&server_addr, sizeof(server_addr)); 
 server_addr.sin_family = AF_INET; 
 server_addr.sin_addr.s_addr = htonl(INADDR_ANY); 
 server_addr.sin_port = htons(SERVER_PORT); 
 
 /* 创建socket */ 
 int server_socket_fd = socket(AF_INET, SOCK_DGRAM, 0); 
 if(server_socket_fd == -1) 
 { 
  perror("Create Socket Failed:"); 
  exit(1); 
 } 
 
 /* 绑定套接口 */ 
 if(-1 == (bind(server_socket_fd,(struct sockaddr*)&server_addr,sizeof(server_addr)))) 
 { 
  perror("Server Bind Failed:"); 
  exit(1); 
 } 
 
 /* 数据传输 */ 
 while(1) 
 {  
  /* 定义一个地址，用于捕获客户端地址 */ 
  struct sockaddr_in client_addr; 
  socklen_t client_addr_length = sizeof(client_addr); 
 
  /* 接收数据 */ 
  char buffer[BUFFER_SIZE]; 
  bzero(buffer, BUFFER_SIZE); 
  if(recvfrom(server_socket_fd, buffer, BUFFER_SIZE,0,(struct sockaddr*)&client_addr, &client_addr_length) == -1) 
  { 
   perror("Receive Data Failed:"); 
   exit(1); 
  } 
 
  /* 从buffer中拷贝出file_name */ 
  char file_name[FILE_NAME_MAX_SIZE+1]; 
  bzero(file_name,FILE_NAME_MAX_SIZE+1); 
  strncpy(file_name, buffer, strlen(buffer)>FILE_NAME_MAX_SIZE?FILE_NAME_MAX_SIZE:strlen(buffer)); 
  printf("%s\n", file_name); 
 } 
 close(server_socket_fd); 
 return 0; 
}