On Thu, Oct 29, 2009 at 3:45 AM, Robin Green wrote:

This is not in any way specific to Haskell, but I know a number of packages on Hackage have executables with command-line options, so:

The non-Haskell program get_iplayer has an excellent idea for command-line options parsing. Rather than having to remember two separate syntaxes, one for command line options and one for a preferences file, the user can simply type

get_iplayer --prefs-add --OPTION[=VALUE]

which will add the equivalent of --OPTION[=VALUE] to the get_iplayer preferences file (and do nothing else). So it's like a special "preferences file manipulation mode" of the program.

There are also the following options, as described by --help:

 --prefs-clear                    Remove *ALL* saved user or preset options  --prefs-del                      Remove specified saved user or preset options  --prefs-show                     Show saved user or preset options

(This also means that the user doesn't have to remember the filename of the preferences file.)

I think this sort of thing would be a good idea for *any* program that has command-line options that some user might want to hold constant across several runs.

-- Robin

Good idea, thanks for mentioning it. Geremy Condra