While I agree that $HOME/.apl-history is more generally useful, I can also make a case for having the history file's location be relative to the working directory:
Assume that you're a consultant or contractor working on APL projects for a number of clients. You cd to the directory for a client's project, start up APL, and do your work for that client. The history file remains specific to that client/directory, which is probably what you'd prefer in that situation. Here's my proposal... Have the installer and the Makefile's install target do the following: 1. Confirm that $HOME exists. 2. Install $HOME/.gnu-apl/preferences from the template. 3. Edit the user's preference file to set READLINE_HISTORY_PATH using the absolute path to $HOME. This should address Blake's concern about keeping the installation process simple, provide what (I think) is the more useful general case while not precluding other choices, and have a reasonable fallback on platforms that don't set $HOME.
