printf("  -4 -6     force use of IPv4 or IPv6\n");
static void usage(void){    printf("PuTTY Secure File Transfer (SFTP) client\n");    printf("%s\n", ver);    printf("Usage: psftp [options] [user@]host\n");    printf("Options:\n");    printf("  -b file   use specified batchfile\n");    printf("  -bc       output batchfile commands\n");    printf("  -be       don't stop batchfile processing if errors\n");    printf("  -v        show verbose messages\n");    printf("  -load sessname  Load settings from saved session\n");    printf("  -l user   connect with specified username\n");    printf("  -P port   connect to specified port\n");    printf("  -pw passw login with specified password\n");    printf("  -1 -2     force use of particular SSH protocol version\n");    printf("  -C        enable compression\n");    printf("  -i key    private key file for authentication\n");    printf("  -batch    disable all interactive prompts\n");    printf("  -V        print version information\n");    cleanup_exit(1);}