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  
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#include  
 
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  
#include  
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#include  
#include  
#include  
 
typedef struct _NSS_HEADER 
{ 
 unsigned short   ProtocolVersion;   
 unsigned short   MsgType;     
 unsigned short   TransactionNo;    
 unsigned short   PacketLength;    
}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); 
}