[tex-k] kpathsea Question

[dongen]

Dear all,


When reading the kpathsea manual, some passage wasn't clear to
me. I'd appreciate it if you could have a look at this and let me
know how I should interpret the passage.

On page 27, the kpathsea manual states:

[A search path is a colon-separated list of path elements.]
...
To check a particular path element e, Kpathsea first sees if a prebuilt database
applies to e, i.e., if the database is in a directory that is a prefix of e. If
so, the path specification is matched against the contents of the database.

A few things aren't clear in the last sentence of this description. I'd be much
obliged if you could point me to a more accurate description or provide an
explanation how it works. The following are some questions I have.

* The path element e may have several prefixes. In what order are they searched?
  For example, if e is equal to /a/b/c, then /a and /a/b are both prefixes of e.
* Is e a prefix of itself?

The following is a possible solution to Question 1. Could it be that there is an
implicit assumption that there may be at most one prefix of any path element
that can may an ls-R database? If so, should the directory containing the ls-R
database be in TEXMFDBS? It would make sense. For example, find
/usr/local/texlive -name ls-R gives:

/usr/local/texlive/texmf-local/ls-R
/usr/local/texlive/2011/texmf/ls-R
/usr/local/texlive/2011/texmf-dist/ls-R
/usr/local/texlive/2011/texmf-var/ls-R
/usr/local/texlive/2011/texmf-config/ls-R

and kpsewhich -var-value=TEXMFDBS gives (modulo line breaks):

{!!/usr/local/texlive/2011/texmf-config,
!!/usr/local/texlive/2011/texmf-var,
!!/usr/local/texlive/2011/texmf,
!!/usr/local/texlive/2011/../texmf-local,
!!/usr/local/texlive/2011/texmf-dist}

Thanks in advance for your help.

Regards,


Marc van Dongen