Sometimes it may be necessary to execute an external command that takes a long time to complete, long enough that the user needs visual feedback while it is running to show that the process is still alive. UIOP provides fantastic tools for running external commands in a portable manner but it was not obvious to me how to show the external command’s output to the user while it was still busy. I also wanted to execute the external command in a synchronous fashion, i.e. my lisp application mus...
