tcp客户端示例

#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 str_echo(int sockfd, unsigned short no) { ssize_t readLen; ssize_t writeLen; char buf[8]; NSS_HEADER *hdr = (NSS_HEADER*)buf; memset( hdr, 0, sizeof(NSS_HEADER) ); hdr->TransactionNo = no; // 写数据 int nWriteLen = 0; while ( true ) { writeLen = write(sockfd, &buf[nWriteLen], sizeof(NSS_HEADER)-nWriteLen); // printf( "write %d/n", writeLen); if (writeLen < 0 && errno == EINTR) { continue; } else if ( writeLen < 0 ) { perror ( "write:" ); return -1; } nWriteLen += writeLen; // 已写完，直接返回 if (nWriteLen >= sizeof(NSS_HEADER) ) { break; } } printf( "send data successed. trans no: %d/n", no ); // 读数据 int nReadLen = 8; while ( true ) { readLen = read(sockfd, buf, nReadLen); // printf( "read: %d/n", readLen ); if (readLen < 0 && errno == EINTR) { continue; } else if ( readLen <= 0 ) { perror( "read:"); return -1; } else { nReadLen -= readLen; if (nReadLen <= 0 ) { break; } } } printf( "read response successed./n" ); return 0; } 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"); while( true ) { int socketFd; struct sockaddr_in svrAddr; struct sockaddr_in localAddr; socketFd = socket (AF_INET, SOCK_STREAM, 0); if ( -1 == socketFd ) { perror( "socket:" ); continue; } // 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); continue; } // 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])); // 不断重连 int connResult = connect(socketFd, (struct sockaddr *) &svrAddr, sizeof(svrAddr)); if ( -1 == connResult ) { perror( "connect:" ); sleep(10); close(socketFd); continue; } printf (" connect %s:%s successed./n", argv[3], argv[4] ); static unsigned short no = 0; // 连接成功，每分钟发送一次数据 for ( ; ; ) { if ( -1 == str_echo(socketFd, no++) ) { break; } sleep( 60 ); } close(socketFd); } }

tcp服务器源码示例

#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> 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; void str_echo(int sockfd) { ssize_t readLen; ssize_t writeLen; char buf[8]; while ( true ) { readLen = read(sockfd, buf, 8); if (readLen < 0 && errno == EINTR) { continue; } else if ( readLen <= 0 ) { perror( "read:"); return ; } printf( "recv data successed. data len: %d/n", readLen ); int nWriteLen = 0; while ( true ) { writeLen == write(sockfd, &buf[nWriteLen], readLen-nWriteLen); if (writeLen < 0 && errno == EINTR) { continue; } else if ( writeLen < 0 ) { perror ( "write:" ); return; } nWriteLen += writeLen; // 已写完，直接返回 if (nWriteLen >= readLen ) { break; } } printf( "send data successed. data len: %d/n", readLen ); } } int main(int argc, char **argv) { printf( "server ip: %s/n", argv[1] ); printf( "server port: %s/n", argv[2] ); printf( "/nservice starting ... /n/n" ); int listenfd, connfd; pid_t childpid; socklen_t clilen; struct sockaddr_in cliaddr, servaddr; listenfd = socket (AF_INET, SOCK_STREAM, 0); if ( -1 == listenfd ) { perror( "socket:" ); exit(-1); } // 设置地址可复用 int option = 1; setsockopt( listenfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option) ); memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = inet_addr( argv[1]); servaddr.sin_port = htons (atoi(argv[2])); int bindResult = bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr)); if ( -1 == bindResult ) { perror( "bind:" ); exit(-1); } int listenResult = listen(listenfd, 5); if ( -1 == listenResult ) { perror( "listen:" ); exit(-1); } for ( ; ; ) { clilen = sizeof(cliaddr); connfd = accept(listenfd, (struct sockaddr *) &cliaddr, &clilen); if ( -1 == connfd ) { perror( "accept:" ); continue; } printf ("accept %s successed.fd: %d/n", inet_ntoa(cliaddr.sin_addr), connfd ); if ( (childpid = fork()) == 0) { /* child process */ close(listenfd); /* close listening socket */ str_echo(connfd); /* process the request */ printf ("disconnect from %d ./n", connfd ); exit (0); } } close(connfd); /* parent closes connected socket */ }