Linux中使用C语言实现基于UDP协议的Socket通信示例

linux下udp服务器端源码示例：

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

int main(int argc, char **argv)
{
 printf("server ip: %s/n", argv[1]);
 printf("server port: %s/n", argv[2]); 

 printf("/n service starting.../n/n");
 int  socketFd;
 struct sockaddr_in svrAddr;
 struct sockaddr_in localAddr; 

 socketFd = socket (AF_INET, SOCK_DGRAM, 0);
 if ( -1 == socketFd )
 {
  perror( "socket:" );
  exit(-1);
 } 

 // 设置地址可复用
 int option = 1;
 setsockopt( socketFd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) );
 // 客户端IP
 memset(&localAddr, 0, sizeof(localAddr));
 localAddr.sin_family = AF_INET;
 localAddr.sin_addr.s_addr = inet_addr( argv[1]);
 localAddr.sin_port = htons (atoi(argv[2])); 

 int bindResult = bind(socketFd, (struct sockaddr *) &localAddr, sizeof(localAddr));
 if ( -1 == bindResult )
 {
  perror( "bind:" );
  close(socketFd);
  exit(-1);
 } 

 // 服务器IP
 memset(&svrAddr, 0, sizeof(svrAddr));
 svrAddr.sin_family = AF_INET;
 svrAddr.sin_addr.s_addr = inet_addr( argv[1]);
 svrAddr.sin_port = htons (atoi(argv[2]));
 char tempBuff[2048] = {0}; 

 for ( ; ; )
 {
  // 接收数据
  struct sockaddr_in fromAddr;
  memset((char *)&fromAddr, 0, (int)sizeof(fromAddr));
  socklen_t fromLen = sizeof(fromAddr);
  ssize_t result = recvfrom( socketFd, tempBuff, sizeof(tempBuff), 0, (struct sockaddr *)&fromAddr, &fromLen);
  if ( -1 == result )
  {
   perror("recvfrom:");
   continue;
  }
  else
  {
   printf( "recv data %s successed. data len: %d/n", inet_ntoa(fromAddr.sin_addr), result );
   printf( "data:/n");
   for ( int i = 0; i < result; i++ )
   {
    printf( "%02x ", tempBuff[i] );
    if ( (i+1)%16 == 0 )
    {
     printf( "/n" );
    }
   }
   printf( "/n" );
  } 

  // 发送数据
  result = sendto( socketFd, tempBuff, result, 0, (struct sockaddr*)&fromAddr, sizeof(fromAddr));
  if ( -1 == result )
  {
   perror("sendto:");
  }
  else
  {
   printf("send data success. data len:%d/n", result );
  }
  sleep( 60 );
 }
 close(socketFd);
}

linux下udp客户端源码示例：

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

typedef struct _NSS_HEADER
{
 unsigned short   ProtocolVersion;  /* 协议版本信息 */
 unsigned short   MsgType;    /* 消息类型 */
 unsigned short   TransactionNo;   /* 传输编号 */
 unsigned short   PacketLength;   /* 数据包长度,包括Header */
}NSS_HEADER; 

int main(int argc, char **argv)
{
 printf("client ip: %s/n", argv[1]);
 printf("client port: %s/n", argv[2]);
 printf("server ip: %s/n", argv[3]);
 printf("server port: %s/n", argv[4]); 

 printf("/n service starting.../n/n");
 int  socketFd;
 struct sockaddr_in svrAddr;
 struct sockaddr_in localAddr; 

 socketFd = socket (AF_INET, SOCK_DGRAM, 0);
 if ( -1 == socketFd )
 {
  perror( "socket:" );
  exit(-1);
 } 

 // 设置地址可复用
 int option = 1;
 setsockopt( socketFd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) );
 // 客户端IP
 memset(&localAddr, 0, sizeof(localAddr));
 localAddr.sin_family = AF_INET;
 localAddr.sin_addr.s_addr = inet_addr( argv[1]);
 localAddr.sin_port = htons (atoi(argv[2])); 

 int bindResult = bind(socketFd, (struct sockaddr *) &localAddr, sizeof(localAddr));
 if ( -1 == bindResult )
 {
  perror( "bind:" );
  sleep(10);
  close(socketFd);
  exit(-1);
 } 

 // 服务器IP
 memset(&svrAddr, 0, sizeof(svrAddr));
 svrAddr.sin_family = AF_INET;
 svrAddr.sin_addr.s_addr = inet_addr( argv[3]);
 svrAddr.sin_port = htons (atoi(argv[4]));
 char tempBuff[2048] = {0}; 

 // 每分钟发送一次数据
 NSS_HEADER hdr;
 memset( &hdr, 0, sizeof(NSS_HEADER));
 for ( ; ; )
 {
  // 发送数据
  hdr.TransactionNo++;
  ssize_t result = sendto( socketFd, &hdr, sizeof(NSS_HEADER), 0, (struct sockaddr*)&svrAddr, sizeof(svrAddr));
  if ( -1 == result )
  {
   perror("sendto:");
  }
  else
  {
   printf("send data success. data len:%d/n", result );
  } 

  // 接收数据
  struct sockaddr_in fromAddr;
  memset((char *)&fromAddr, 0, (int)sizeof(fromAddr));
  socklen_t fromLen = sizeof(fromAddr);
  result = recvfrom( socketFd, tempBuff, sizeof(tempBuff), 0, (struct sockaddr *)&fromAddr, &fromLen);
  if ( -1 == result )
  {
   perror("recvfrom:");
  }
  else
  {
   printf( "recv data %s successed. data len: %d/n", inet_ntoa(fromAddr.sin_addr), result );
   printf( "data:/n");
   for ( int i = 0; i < result; i++ )
   {
    printf( "%02x ", tempBuff[i] );
    if ( (i+1)%16 == 0 )
    {
     printf( "/n" );
    }
   }
   printf("/n");
  }
  sleep( 60 );
 }
 close(socketFd);
}