Run the executable program `locate' with a filter.
This function is similar to the function `locate', which see.
The difference is that, when invoked interactively, the present function
prompts for both SEARCH-STRING and FILTER. It passes SEARCH-STRING
to the locate executable program. It produces a `*Locate*' buffer
that lists only those lines in the output of the locate program that
contain a match for the regular expression FILTER; this is often useful
to constrain a big search.
ARG is the interactive prefix arg, which has the same effect as in `locate'.
When called from Lisp, this function is identical with `locate',
except that FILTER is not optional. (fn SEARCH-STRING FILTER &optional ARG)