[tex-k] Speed of kpsewhich when querying the repertories of the TeX installation

[Karl Berry]

    I may write a Makefile which will act after querying
    the repertories locations. But one tenth of a second
    for each kpsewhich call is a lot.

Save the result instead of making the same call thousands of times.  I
don't agree that 100 ms is such a horrible time to do all those
filesystem operations.  In fact, it seems rather quick to me.
    
    Could it be imagined to have some kpsewhichdir utility

1) I fail to see how making a utility restricted to a single variable
could speed anything up.  Surely what takes the time is looking for the
config files in all the possible directories, and (more so) reading the
ls-R file.  If you run kpsewhich --debug=-1 --expand-path=\$TEXMFHOME,
you will see what it's doing.

2) Regardless, the idea of a utility dedicated to a single variable
sounds wrong in principle to me and I don't think it should be done.

    the environment variable $TEXMFHOME 

So far as I can see, if the envvar is set, its value is already (has
always been) returned "instantly".  The lookups are only done if they
need to be.

karl