instead of stdio. This gives BSD grep a very big performance boost,
its speed is now almost comparable to GNU grep.
Submitted by: Dimitry Andric <dimitry@andric.com>
Approved by: delphij (mentor)
former may be safer but in this case it doesn't add extra
safety [1]
- Fix -w option [2]
- Fix handling of GREP_OPTIONS [3]
- Fix --line-buffered
- Make stdin input imply --line-buffered so that tail -f can be piped
to grep [4]
- Imply -h if single file is grepped, this is the GNU behaviour
- Reduce locking overhead to gain some more performance [5]
- Inline some functions to help the compiler better optimize the code
- Use shortcut for empty files [6]
PR: bin/149425 [6]
Prodded by: jilles [1]
Reported by: Alex Kozlov <spam@rm-rf.kiev.ua> [2] [3],
swell.k@gmail.com [2],
poyopoyo@puripuri.plala.or.jp [4]
Submitted by: scf [5],
Shuichi KITAGUCHI <ki@hh.iij4u.or.jp> [6]
Approved by: delphij (mentor)
Deliverables: Small and clean code (1,4 KSLOC vs GNU's 8,5 KSLOC),
lower memory usage than GNU grep, GNU compatibility,
BSD license.
TODO: Performance is somewhat behind GNU grep but it is only
significant for bigger searches. The reason is complex, the
most important factor is that GNU grep uses lots of
optimizations to improve the speed of the regex library.
First, we need a modern regex library (practically by adopting
TRE), add support for GNU-style non-standard regexes and then
reevalute the performance issues and look for bottlenecks. In
the meantime, for those, who need better performance, it is
possible to build GNU grep by setting WITH_GNU_GREP.
Approved by: delphij (mentor)
Obtained from: OpenBSD (http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/grep/),
freegrep (http://github.com/howardjp/freegrep)
Sponsored by: Google SoC 2008
Portbuild tests run by: kris, pav, erwin
Acknowledgements to: fjoe (as SoC 2008 mentor),
everyone who helped in reviewing and testing
