I have made a toy interactive console program that is basically an interpreter:
$ myprogram
> this is user input
this is program output
script — make typescript of terminal session:
script -c "myprogram" file.log
The whole session will be logged to file.log
An easy way is to use the script command. It just stores your whole terminal session. Run it with:
script my-interactive-session.log program
As two processes can't read the same input two tees are needed, one which reads terminal input and writes to program standard input and file.log another which reads program standard output and writes into terminal output and file.log:
tee -a file.log | program | tee -a file.log
The simpler form could be
tee >(myprogram) | tee -a file.log
If you want to prevent input being shown again to the screen:
tee -a file.log | myprogram | tee -a file.log