[Toybox] pcre2grep

[Rob Landley]

I see
http://lists.landley.net/pipermail/toybox-landley.net/2018-August/009585.html
but never got a copy through the list, I'm guessing gmail bounced it as spam.

I've spent a lot of this week wrestling with the deflate code, trying to get it
into lib/ and filling in the "else" case of the #ifdef zlib stuff. I was hoping
to implement the missing parts of compression side (right now deflate is just
doing store), but spent a lot of time just getting back up to speed and cleaning
up overgrowth.

I'm aware toybox grep needs --color, which is basically a genericization of the
grep -o logic. (Instead of printing only the matches, print both match and
non-match in different colors. Most of the plumbing's there, but built around
the wrong assumption.)

The problem with adding perl regex support to toybox grep is we use libc's
regex. I can add a config option to pull in another library, but don't know
what's out there for this?

Rob