Linux Socket程式設計例項(一個Hello World程式)
阿新 • • 發佈：2018-12-27
在Linux下寫了個小的socket程式，分為客戶端和伺服器端,服務端開一個埠(2000),做為一個daemon,等待客戶的連線請求.一旦有客戶連線,伺服器端打印出客戶端的IP地址和埠,並且向伺服器端傳送歡迎資訊和時間.下面是服務端的程式碼(tcpserver.c).由於這只是個簡單的程式，所以只用了單執行緒實現!
/**//* *
* Tcp Server program, It is a simple example only. * zhengsh 200520602061 2 * when client connect to server, send a welcome message and timestamp in server.
#include <stdio.h> #include <sys/socket.h> #include <unistd.h> #include <sys/types.h> #include <netinet/in.h> #include <stdlib.h> #include <time.h> #define SERVER_PORT 20000 // define the defualt connect port id #define LENGTH_OF_LISTEN_QUEUE 10 // length of listen queue in server #define BUFFER_SIZE 255 #define WELCOME_MESSAGE "welcome to connect the server. " int main(int argc, char** argv)
{ int servfd,clifd; struct sockaddr_in servaddr,cliaddr; if ((servfd = socket(AF_INET,SOCK_STREAM, 0 )) <0 )
{ printf( " create socket error!\n exit( 1 );
} bzero( & servaddr, sizeof (servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_port = htons(SERVER_PORT); servaddr.sin_addr.s_addr = htons(INADDR_ANY); if (bind(servfd,( struct sockaddr * ) & servaddr, sizeof (servaddr)) <0 ) { printf( " bind to port %d failure!\n " ,SERVER_PORT); exit( 1 ); } if (listen(servfd,LENGTH_OF_LISTEN_QUEUE) <0 ) { printf( " call listen failure!\n " ); exit( 1 ); } while ( 1 ) { // server loop will nerver exit unless any body kill the process char buf[BUFFER_SIZE]; long timestamp; socklen_t length =sizeof (cliaddr); clifd = accept(servfd,( struct sockaddr * ) & cliaddr, & length); if (clifd <0 ) { printf( " error comes when call accept!\n " ); break ; } strcpy(buf,WELCOME_MESSAGE); // inet_ntop(INET_ADDRSTRLEN,cliaddr.sin_addr,buf,BUFFER_SIZE); printf( " from client,IP:%s,Port:%d\n " ,inet_ntoa(cliaddr.sin_addr),ntohs(cliaddr.sin_port)); timestamp = time(NULL); strcat(buf, " timestamp in server: " ); strcat(buf,ctime( & timestamp)); send(clifd,buf,BUFFER_SIZE, 0 ); close(clifd); }// exit close(servfd); return0 ;}
客戶每次用一個隨機的埠連線伺服器,並接收來自伺服器的歡迎資訊,然後打印出來(tcpclient).執行的時候接受一個引數,也就是伺服器的ip地址.
/**//* Tcp client program, It is a simple example only. * zhengsh 200520602061 2 * connect to server, and echo a message from server.*/ #include <stdio.h>#include <sys/socket.h>#include <unistd.h>#include <sys/types.h>#include <netinet/in.h>#include <stdlib.h> #define SERVER_PORT 20000 // define the defualt connect port id #define CLIENT_PORT ((20001+rand())%65536) // define the defualt client port as a random port #define BUFFER_SIZE 255 #define REUQEST_MESSAGE "welcome to connect the server.\n" void usage(char* name){ printf( " usage: %s IpAddr\n " ,name);}int main(int argc, char** argv){ int servfd,clifd,length =0; struct sockaddr_in servaddr,cliaddr; socklen_t socklen =sizeof (servaddr); char buf[BUFFER_SIZE]; if (argc <2 ) { usage(argv[ 0 ]); exit( 1 ); } if ((clifd = socket(AF_INET,SOCK_STREAM, 0 )) <0 ) { printf( " create socket error!\n " ); exit( 1 ); } srand(time(NULL)); // initialize random generator bzero( & cliaddr, sizeof (cliaddr)); cliaddr.sin_family = AF_INET; cliaddr.sin_port = htons(CLIENT_PORT); cliaddr.sin_addr.s_addr = htons(INADDR_ANY); bzero( & servaddr, sizeof (servaddr)); servaddr.sin_family = AF_INET; inet_aton(argv[ 1 ], & servaddr.sin_addr); servaddr.sin_port = htons(SERVER_PORT); // servaddr.sin_addr.s_addr = htons(INADDR_ANY); if (bind(clifd, (struct sockaddr* ) &cliaddr, sizeof (cliaddr)) <0 ) { printf( " bind to port %d failure!\n " ,CLIENT_PORT); exit( 1 ); } if (connect(clifd,( struct sockaddr * ) & servaddr, socklen) <0 ) { printf( " can't connect to %s!\n ", argv[ 1 ]); exit( 1 ); } length = recv(clifd, buf, BUFFER_SIZE, 0); if (length <0) { printf( " error comes when recieve data from server %s! ", argv[1] ); exit( 1 ); } printf( " from server %s :\n\t%s", argv[1], buf); close(clifd); return0;}
程式在Fedora core 4下通過編譯,有幾個warining.但是不影響.
posted on 2006-04-20 17:49 楊粼波 閱讀(15555) 評論(0) 編輯 收藏 引用 所屬分類: 網路程式設計 、Linux程式設計