tcp socket通信例子
tcpclient:#include <stdio.h>#include <stdlib.h>#include <windows.h>#include <string.h>#define HOST_PORT 10000int main(){ WORD wVersionRequested; WSADATA wsaData; int err; wVersionRequested = MAKEWORD( 2, 2 ); err = WSAStartup( wVersionRequested, &wsaData ); if ( err != 0 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ return; } /* Confirm that the WinSock DLL supports 2.2.*/ /* Note that if the DLL supports versions greater */ /* than 2.2 in addition to 2.2, it will still return */ /* 2.2 in wVersion since that is the version we */ /* requested. */ if ( LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ WSACleanup( ); return; } int clientfd = socket(AF_INET, SOCK_STREAM, 0); if(clientfd < 0) { printf("client create socket failed.\n"); return 0; } int on = 1; if(setsockopt(clientfd, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)) < 0) { printf("set socket option failed.\n"); return 0; } struct sockaddr_in servaddr; memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(HOST_PORT); servaddr.sin_addr.S_un.S_addr = inet_addr("192.168.1.56"); char buf[BUFSIZ]; memset(buf,0,BUFSIZ); strncpy(buf,"shawn's client",14); //buf[BUFSIZ] = '\0'; if(connect(clientfd,(const struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) { printf("%d\n",errno); return 0; } int index = 0; for(index = 0; index < 5; index++) { send(clientfd,buf,strlen(buf) + 1, 0); _sleep(10); } strcpy(buf,"end"); send(clientfd,buf,strlen(buf) + 1, 0); closesocket(clientfd); getchar(); return 0;}tcpserver:#include <stdio.h>#include <stdlib.h>#include <windows.h>#define MAX_LISTEN_QUEUE_NUMBER 10#define HOST_PORT 10000#define MAX_PACKET_LENGTH 1400int main(){ WORD wVersionRequested; WSADATA wsaData; int err; wVersionRequested = MAKEWORD( 2, 2 ); err = WSAStartup( wVersionRequested, &wsaData ); if ( err != 0 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ return 0; } /* Confirm that the WinSock DLL supports 2.2.*/ /* Note that if the DLL supports versions greater */ /* than 2.2 in addition to 2.2, it will still return */ /* 2.2 in wVersion since that is the version we */ /* requested. */ if ( LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ WSACleanup( ); return 0; } int servfd, clientfd; servfd = socket(AF_INET, SOCK_STREAM, 0); if(servfd < 0) { printf("server create socket failed.\n"); return 0; } int on = 1; if(setsockopt(servfd, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)) < 0) { printf("set socket option failed.\n"); return 0; } struct sockaddr_in servaddr; struct sockaddr_in clientaddr; memset(&servaddr,0,sizeof(servaddr)); memset(&clientaddr,0,sizeof(clientaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(HOST_PORT); servaddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY); if(bind(servfd, (const struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) { printf("bind failed.\n"); return 0; } if(listen(servfd,10) < 0) { printf("listen failed.\n"); return 0; } char buf[MAX_PACKET_LENGTH]; memset(buf,0,MAX_PACKET_LENGTH); int length = sizeof(clientaddr); int clientRecord[FD_SETSIZE]; int index = 0; for(; index < FD_SETSIZE; index++) clientRecord[index] = -1; fd_set readSet; FD_ZERO(&readSet); FD_SET(servfd,&readSet); int maxfd = servfd; for(;;) { clientfd = accept(servfd, (struct sockaddr *)&clientaddr,&length); for(index = 0; index < FD_SETSIZE; index++) { if(clientRecord[index] < 0) { clientRecord[index] = clientfd; break; } } if(index == FD_SETSIZE) { printf("too many sockets.\n"); break; } for(index = 0; index < FD_SETSIZE; index++) { if(clientRecord[index] > 0) { FD_SET(clientRecord[index],&readSet); maxfd = maxfd > clientRecord[index] ? maxfd : clientRecord[index]; } else break; } struct timeval time; time.tv_sec = 10; time.tv_usec = 0; if(select(maxfd,&readSet,NULL,NULL,&time) <= 0) break; int sockfd; for(index = 0; index < FD_SETSIZE; index++) { if((sockfd = clientRecord[index]) < 0) continue; if(FD_ISSET(sockfd,&readSet)) { while(1) { recv(sockfd,buf,MAX_PACKET_LENGTH,0); printf("%s\n",buf); if(strcmp(buf,"end") == 0) break; } closesocket(sockfd); clientRecord[index] = -1; } } } closesocket(servfd); return 0;}看到一个评论，说的比较在理，于是重新改写了一下，起码做到了真正的非IO阻塞了吧：tcpclient:#include <stdio.h>#include <stdlib.h>#include <windows.h>#include <string.h>#define HOST_PORT 10000int main(){ WORD wVersionRequested; WSADATA wsaData; int err; wVersionRequested = MAKEWORD( 2, 2 ); err = WSAStartup( wVersionRequested, &wsaData ); if ( err != 0 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ return; } /* Confirm that the WinSock DLL supports 2.2.*/ /* Note that if the DLL supports versions greater */ /* than 2.2 in addition to 2.2, it will still return */ /* 2.2 in wVersion since that is the version we */ /* requested. */ if ( LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ WSACleanup( ); return; } int clientfd = socket(AF_INET, SOCK_STREAM, 0); if(clientfd < 0) { printf("client create socket failed.\n"); return 0; } int on = 1; if(setsockopt(clientfd, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)) < 0) { printf("set socket option failed.\n"); return 0; } struct sockaddr_in servaddr; memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(HOST_PORT); servaddr.sin_addr.S_un.S_addr = inet_addr("192.168.1.56"); char buf[BUFSIZ]; memset(buf,0,BUFSIZ); strncpy(buf,"shawn's client",14); //buf[BUFSIZ] = '\0'; if(connect(clientfd,(const struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) { printf("%d\n",errno); return 0; } int index = 0; for(index = 0; index < 5; index++) { send(clientfd,buf,strlen(buf) + 1, 0); _sleep(10); } memset(buf,0,BUFSIZ); strcpy(buf,"end"); send(clientfd,buf,strlen(buf) + 1, 0); closesocket(clientfd); getchar(); return 0;}tcpserver.c:#include <stdio.h>#include <stdlib.h>#include <windows.h>#define MAX_LISTEN_QUEUE_NUMBER 10#define HOST_PORT 10000#define MAX_PACKET_LENGTH 1400int main(){ WORD wVersionRequested; WSADATA wsaData; int err; wVersionRequested = MAKEWORD( 2, 2 ); err = WSAStartup( wVersionRequested, &wsaData ); if ( err != 0 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ return 0; } /* Confirm that the WinSock DLL supports 2.2.*/ /* Note that if the DLL supports versions greater */ /* than 2.2 in addition to 2.2, it will still return */ /* 2.2 in wVersion since that is the version we */ /* requested. */ if ( LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 ) { /* Tell the user that we could not find a usable */ /* WinSock DLL. */ WSACleanup( ); return 0; } int servfd, clientfd; servfd = socket(AF_INET, SOCK_STREAM, 0); if(servfd < 0) { printf("server create socket failed.\n"); return 0; } int on = 1; if(setsockopt(servfd, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)) < 0) { printf("set socket option failed.\n"); return 0; } struct sockaddr_in servaddr; struct sockaddr_in clientaddr; memset(&servaddr,0,sizeof(servaddr)); memset(&clientaddr,0,sizeof(clientaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(HOST_PORT); servaddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY); if(bind(servfd, (const struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) { printf("bind failed.\n"); return 0; } if(listen(servfd,10) < 0) { printf("listen failed.\n"); return 0; } char buf[MAX_PACKET_LENGTH]; memset(buf,0,MAX_PACKET_LENGTH); int length = sizeof(clientaddr); int clientRecord[FD_SETSIZE]; int index = 0; for(; index < FD_SETSIZE; index++) clientRecord[index] = -1; fd_set readSet; FD_ZERO(&readSet); FD_SET(servfd,&readSet); int maxfd = servfd; for(;;) { struct timeval time; time.tv_sec = 10; time.tv_usec = 0; if(select(maxfd,&readSet,NULL,NULL,&time) <= 0) continue; if(FD_ISSET(servfd,&readSet)) { clientfd = accept(servfd, (struct sockaddr *)&clientaddr,&length); for(index = 0; index < FD_SETSIZE; index++) { if(clientRecord[index] < 0) { clientRecord[index] = clientfd; break; } } if(index == FD_SETSIZE) { printf("too many sockets.\n"); break; } } for(index = 0; index < FD_SETSIZE; index++) { if(clientRecord[index] > 0) { FD_SET(clientRecord[index],&readSet); maxfd = maxfd > clientRecord[index] ? maxfd : clientRecord[index]; } else break; } int sockfd; for(index = 0; index < FD_SETSIZE; index++) { if((sockfd = clientRecord[index]) < 0) continue; if(FD_ISSET(sockfd,&readSet)) { while(1) { recv(sockfd,buf,MAX_PACKET_LENGTH,0); printf("%s\n",buf); if(strcmp(buf,"end") == 0) break; } closesocket(sockfd); clientRecord[index] = -1; } } } closesocket(servfd); return 0;}