/* rls.c - a client for a remote directory listing service * usage: rls hostname directory */ #include #include #include #include #include #define oops(msg) { perror(msg); exit(1); } #define PORTNUM 15000 main(int ac, char *av[]) { struct sockaddr_in servadd; /* the number to call */ struct hostent *hp; /* used to get number */ int sock_id, sock_fd; /* the socket and fd */ char buffer[BUFSIZ]; /* to receive message */ int n_read; /* for message length */ if ( ac != 3 ) exit(1); /** Step 1: Get a socket **/ sock_id = socket( AF_INET, SOCK_STREAM, 0 ); /* get a line */ if ( sock_id == -1 ) oops( "socket" ); /* or fail */ /** Step 2: connect to server **/ bzero( &servadd, sizeof(servadd) ); /* zero the address */ hp = gethostbyname( av[1] ); /* lookup host's ip # */ if (hp == NULL) oops(av[1]); /* or die */ bcopy(hp->h_addr, (struct sockaddr *)&servadd.sin_addr, hp->h_length); servadd.sin_port = htons(PORTNUM); /* fill in port number */ servadd.sin_family = AF_INET ; /* fill in socket type */ if ( connect(sock_id,(struct sockaddr *)&servadd, sizeof(servadd)) !=0) oops( "connect" ); /** Step 3: send directory name, then read back results **/ if ( write(sock_id, av[2], strlen(av[2])) == -1) oops("write"); if ( write(sock_id, "\n", 1) == -1 ) oops("write"); while( (n_read = read(sock_id, buffer, BUFSIZ)) > 0 ) if ( write(1, buffer, n_read) == -1 ) oops("write"); close( sock_id ); }