This is agcre, the egrep-alike which uses the libagcre regular expression
library (see pkgsrc/devel/libagcre) to search for regular expressions
in files or in data streams.

In general, the emphasis is on using a modern, predictable, VM-style,
well-featured regexp library, in C, with an MIT license.  In
particular, most Perl regexp features are supported, as are back
references, and UTF-8, and wide characters (wchar_t).

I wouldn't expect anyone to use this as ther main regex engine a la egrep
but this may prove food for thought:

	% time agcre '(a?){9999}aaaaaaaaaaaaaaaaaaaaaaaaaaaaa' dist/tests/2.in
	aaaaaaaaaaaaaaaaaaaaaaaaaaaaa
	0.063u 0.000s 0:00.06 100.0%    0+0k 0+0io 0pf+0w
	% time egrep '(a?){9999}aaaaaaaaaaaaaaaaaaaaaaaaaaaaa' dist/tests/2.in
	^C88.462u 0.730s 1:29.21 99.9%  0+0k 0+0io 0pf+0w
	%
