-w flag matching with an empty pattern was generally 'broken', allowing
matches to occur on any line whether or not it actually matches -w
criteria.
This fix required a good amount of refactoring to address. procline()
is altered to *only* process the line and return whether it was a match
or not, necessary to be able to short-circuit the whole function in case
of this matchall flag. -m flag handling is moved out as well because it
suffers from the same fate as context handling if we bypass any actual
pattern matching.
The matching context (matches, mostly) didn't previously exist outside
of procline(), so we go ahead and create context object for file
processing bits to pass around. grep_printline() was created due to
this, for the scenarios where the matches don't actually matter and we
just want to print a line or two, a la flushing the context queue and
no -o or --color specified.
Damage from this broken behavior would have been mitigated by the fact
that it is unlikely users would invoke grep -w with an empty pattern.
This was identified while checking PR 105221 for problems it this may
cause in BSD grep, but PR 105221 is *not* a report of this behavior.
Submitted by: Kyle Evans <kevans91 at ksu.edu>
Differential Revision: https://reviews.freebsd.org/D10433
Bring a couple of changes from NetBSD:
queue.c (CVS Rev. 1.4. 1.5)
Fix memory leaks.
NULL does not need a cast.
grep.c (CVS Rev. 1.6)
Use the more portable getline.
Obtained from: NetBSD
MFC after: 3 days
- Makefile nit
- Add more CVS/SVN keywords to make it easier to track changes from NetBSD
in case they add further improvements
Approved by: delphij (mentor)
Obtained from: The NetBSD Project
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)
and exclusion patterns [1]
- Some improvements on the exiting code, like replacing memcpy with
strlcpy/strcpy
Approved by: delphij (mentor)
Pointed out by: bf [1], des [1]
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
