The three modes for wios are.
The option is -r or --rec. You can specify the wave file name to record name using -o. The default file name is da.wav
The option is -p or --play. You can specify the wave file name to play using -i. The default file name is ad.wav
The option is -s or --sync. You can specify the wave file name to play using -i and the file to record using -o. wios will then play the specified file and simultaneously record to another specified file.