简单的linux c socket例子

服务端代码：

# include < stdio. h> # include < string . h> # include < sys/ socket . h> # include < netinet/ in. h> # define MAXDATASIZE 1024 # define SERVERPORT 8000 # define MAXCONN_NUM 10 int main( ) {     char buf[ MAXDATASIZE] ;     int sockfd, new_fd, numbytes;     struct sockaddr_in server_addr;     struct sockaddr_in client_addr;     int sin_size;     if ( ( sockfd = socket ( AF_INET , SOCK_STREAM , 0) ) = = - 1) {         perror ( "socket error" ) ;         return 1;     }     memset ( & client_addr, 0, sizeof ( struct sockaddr ) ) ;     server_addr. sin_family = AF_INET ;     server_addr. sin_port = htons ( SERVERPORT) ;     server_addr. sin_addr. s_addr = INADDR_ANY ;     if ( bind ( sockfd, ( struct sockaddr * ) & server_addr, sizeof ( struct sockaddr ) ) = = - 1) {         perror ( "bind error" ) ;         return 1;     }     if ( listen ( sockfd, MAXCONN_NUM) = = - 1) {         perror ( "listen error" ) ;         return 1;     }     while ( 1) {         sin_size = sizeof ( struct sockaddr_in ) ;         if ( ( new_fd = accept ( sockfd, ( struct sockaddr * ) & client_addr, & sin_size) ) = = - 1) {             perror ( "accept error" ) ;             continue ;         }         printf ( "server: got connection from %s/n" , inet_ntoa( client_addr. sin_addr) ) ;         if ( ( numbytes = recv ( new_fd, buf, MAXDATASIZE, 0) ) = = - 1) {             perror ( "recv error" ) ;             return 1;         }         if ( numbytes) {             buf[ numbytes] = '/0' ;             printf ( "received: %s/n" , buf) ;             sleep ( 3) ;         }         printf ( "send: hi~~/n" ) ;         if ( send ( new_fd, "hi~~" , 5, 0) = = - 1) {             perror ( "send error" ) ;             return 1;         }         close ( new_fd) ;     }     return 0; }

客户端代码：

# include < stdio. h> # include < string . h> # include < sys/ socket . h> # include < netinet/ in. h> # define MAXDATASIZE 1024 # define SERVERIP "192.168.0.2" # define SERVERPORT 8000 int main( int argc, char * argv[ ] ) {     char buf[ MAXDATASIZE] ;     int sockfd, numbytes;     struct sockaddr_in server_addr;     if ( ( sockfd = socket ( AF_INET , SOCK_STREAM , 0) ) = = - 1) {         perror ( "socket error" ) ;         return 1;     }     memset ( & server_addr, 0, sizeof ( struct sockaddr ) ) ;     server_addr. sin_family = AF_INET ;     server_addr. sin_port = htons ( SERVERPORT) ;     server_addr. sin_addr. s_addr = inet_addr( SERVERIP) ;     if ( connect ( sockfd, ( struct sockaddr * ) & server_addr, sizeof ( struct sockaddr ) ) = = - 1) {         perror ( "connect error" ) ;         return 1;     }     printf ( "send: Hello, world!/n" ) ;     if ( send ( sockfd, "Hello, world!" , 14, 0) = = - 1) {         perror ( "send error" ) ;         return 1;     }     if ( ( numbytes = recv ( sockfd, buf, MAXDATASIZE, 0) ) = = - 1) {         perror ( "recv error" ) ;         return 1;     }     if ( numbytes) {         buf[ numbytes] = '/0' ;         printf ( "received: %s/n" , buf) ;     }     close ( sockfd) ;     return 0; }