Default program-prefix option

[Linus Walleij]

In february there was a mail to the list asking how to set a default 
program-prefix, with the same effect as giving it to the command line 
using ./configure --program-prefix=foo.

I had to achieve this and it turns out the following hack in a 
configure.ac/.in file will do:

# This can be overridden by the command line switch
if test "$program_prefix" = NONE; then
   program_prefix=foo
   program_transform_name="s,^,$program_prefix,;$program_transform_name"
fi

The manipulation of program_transform_name is necessary because program 
prefix is rewritten into a transformation regexp before any commands in 
the configure.ac/.in file are executed.

It would of course be preferable if there was an autoconf macro for this, 
something along the line AC_DEFAULT_PROGRAM_PREFIX(foo) so that one does 
not have to use such hacks.

Yours,
Linus Walleij