Bug 201650
| Summary: | (e)grep handling regexp wrong | ||||||
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| Product: | Base System | Reporter: | Franz Bettag <franz> | ||||
| Component: | bin | Assignee: | freebsd-bugs (Nobody) <bugs> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Many People | CC: | ben.rubson, chris, emaste, feld, freebsd, kevans, me, steve | ||||
| Priority: | --- | Keywords: | patch | ||||
| Version: | CURRENT | ||||||
| Hardware: | Any | ||||||
| OS: | Any | ||||||
| Attachments: |
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Description
Franz Bettag
2015-07-17 14:51:13 UTC
% echo "abc" | bsdgrep -e "^[a-z]" -o a % echo "abc" | grep -e "^[a-z]" -o a b c bsdgrep gets it right, but grep does not. Our GPL'd grep must be old and has this bug? RHEL 5 -bash-3.2$ echo "abc" | grep -e "^[a-z]" -o a b c -bash-3.2$ grep -V grep (GNU grep) 2.5.1 Copyright 1988, 1992-1999, 2000, 2001 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. RHEL 6 -bash-4.1$ echo "abc" | grep -e "^[a-z]" -o a -bash-4.1$ grep -V GNU grep 2.6.3 Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. grep went GPLv3 at 2.5.3, so we might not be able to backport the fix. Note that -o was a brand new feature in 2.5.1. Perhaps we should just flip the switch and move to bsdgrep for 11-RELEASE? Matching any four characters at the beginning of a line also fails: % echo "1234 1234 1234" | egrep -o '^....' 1234 123 4 12 Interestingly enough, this also fails with bsdgrep: % echo "1234 1234 1234" | bsdgrep -o '^....' 1234 123 4 12 Created attachment 172418 [details]
Patch for fixing anchor treatment in BSD grep.
The attached patch solves the bsdgrep that I reported in the previous comment. bsdgrep tries to find multiple matches by updating the starting offset after finding a match. However, the REG_NOTBOL flag should be set for offsets beyond 0, to ensure that regexec treats anchors correctly.
Patch for the same issue in OpenBSD's grep: https://marc.info/?l=openbsd-tech&m=147206598501753&w=2 grep also fails with case : # echo AAA > test # grep a test # grep "[a-z]" test AAA # echo BBB | grep "[a-z]" BBB # grep -V grep (GNU grep) 2.5.1-FreeBSD # uname -r 11.0-RC3 Quite dangerous issue, could we think about having it corrected for FreeBSD 11 release ? Many thanks, Ben Note that B can be in the range a-z depending on collation settings: http://unix.stackexchange.com/questions/15980/does-should-lc-collate-affect-character-ranges You're right Daniël, I must face this. What is strange is that on 2 different systems with the same LC_COLLATE, results are not the same. Really disturbing. Thank you for the link, and sorry for the noise... Issues expressed in this thread exist with gnugrep, but none exist with bsdgrep at this point in time. This should be able to be closed with the installation of bsdgrep as /usr/bin/grep. A commit references this bug: Author: kevans Date: Tue Dec 8 14:05:26 UTC 2020 New revision: 368439 URL: https://svnweb.freebsd.org/changeset/base/368439 Log: src.opts.mk: switch to bsdgrep as /usr/bin/grep This has been years in the making, and we all knew it was bound to happen some day. Switch to the BSDL grep implementation now that it's been a little more thoroughly tested and theoretically supports all of the extensions that gnugrep in base had with our libregex(3). Folks shouldn't really notice much from this update; bsdgrep is slower than gnugrep, but this is currently the price to pay for fewer bugs. Those dissatisfied with the speed of grep and in need of a faster implementation should check out what textproc/ripgrep and textproc/the_silver_searcher can do for them. I have some WIP to make bsdgrep faster, but do not consider it a blocker when compared to the pros of switching now (aforementioned bugs, licensing). PR: 228798 (exp-run) PR: 128645, 156704, 166842, 166862, 180937, 193835, 201650 PR: 232565, 242308, 246000, 251081, 191086, 194397 Relnotes: yes, please Changes: head/share/mk/src.opts.mk No longer reproducible in 13.1-RELEASE-p3 (with bsdgrep 2.6.0-FreeBSD or GNU/grep 3.8): $ echo "abc" | /usr/bin/grep -Eo '^[a-z]' a $ echo "abc" | /usr/local/bin/ggrep -Eo '^[a-z]' a So...I guess this report can be closed? Yep seems fixed :) |
