#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);  }   // 設置地址可復用  int option = 1;  setsockopt( socketFd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) );  // 客戶端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);  }   // 服務器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 ( ; ; )  {   // 接收數據   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" );   }      // 發送數據   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); } 

#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;  /* 協議版本信息 */  unsigned short   MsgType;    /* 消息類型 */  unsigned short   TransactionNo;   /* 傳輸編號 */  unsigned short   PacketLength;   /* 數據包長度,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);  }   // 設置地址可復用  int option = 1;  setsockopt( socketFd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) );  // 客戶端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);  }   // 服務器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};   // 每分鐘發送一次數據  NSS_HEADER hdr;  memset( &hdr, 0, sizeof(NSS_HEADER));  for ( ; ; )  {   // 發送數據   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 );   }    // 接收數據   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); }