Re: --with-foo= vs. FOO=${FOO:-foo_default}

[Akim Demaille]

| > From: address@hidden
| > Date: Sun, 1 Sep 2002 08:57:10 -0400 (EDT)
| > 
| > So which is the recommended practices way to handle this with autoconf?
| 
| The GNU coding standards say this:
| 
|    You will note that the categories `--with-' and `--enable-' are
|    narrow: they *do not* provide a place for any sort of option you might
|    think of.  That is deliberate.  We want to limit the possible
|    configuration options in GNU software.  We do not want GNU programs to
|    have idiosyncratic configuration options.
| 
| So the recommended practice is to not do what you're doing.  :-)
| 
| If you really want to do it anyway, despite the recommendation, I
| suggest using environment variables.  For example, with GNU a2ps you
| can say this:
| 
|   with_medium=a4 ./configure
| 
| (With a2ps configure you can also use the --with-medium option, but
| that runs a bit contrary to the coding standards.)

Just for the records: the fact that with_medium ./configure works is a
mere consequence of --with-medium support.  And I introduced this
--with only because, amongst the zillions of runtime options to be
defined in /etc/a2ps.cfg, this one defaulted to A4 makes half the
planet complain, and defaulted to Letter makes the other half complain
(which does imply, indeed, that the whole planet uses a2ps :).  And
finally, what I did at that time (way before my being swallowed by
Autoconf) is certainly not what I'd recommend today (it's not even
properly quoted :).