Xref: utzoo comp.unix.i386:604 comp.bugs.sys5:1153 Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!gem.mps.ohio-state.edu!ginosko!uunet!mcsun!ukc!warwick!bsrdp From: bsrdp@warwick.ac.uk (H Boothroyd) Newsgroups: comp.unix.i386,comp.bugs.sys5 Subject: Re: 386/ix V2.0.2 breaks awk Summary: The parsing problem is more widespread Message-ID: <264@orchid.warwick.ac.uk> Date: 28 Sep 89 16:17:44 GMT References: <1456@redsox.bsw.com> Organization: Warwick Business School, Warwick University, UK Lines: 48 In article <1456@redsox.bsw.com> campbell@redsox.bsw.com (Larry Campbell) writes: > A few weeks ago, I upgraded my 386/ix system from 2.0.1 to 2.0.2, and one of > my nightly news administration scripts broke. The problem is caused by a > bug in nawk, which in 2.0.2 seems to have become the standard awk. [Example deleted] A version of gawk gave me exactly the same problem here when I switched a news script to it last week: Gnu Awk (gawk) 2.10 beta 07 Apr 1989 running on a Sun 4. However, an earlier MSDOS version has no problems with parsing the compound pattern: Gnu Awk (gawk) 2.02 beta (PC) 23 Dec 1988 . From the evidence of the experience of Larry and me, in such widely different contexts, my provisional conclusions are: * the parsing bug is a 1989 creation of awk/gawk programmers, * the defective code is being copied around the awk/gawk world. Experiments show that the nearest to full generality that the 2.10 parser can manage with plain patterns of the form /regularexpression/ is: /re/ && .... && $0~/re/ && ... in which all plain /re/ forms must come first and no parentheses can be used round plain /re/ forms. Which is a far cry from the specification in the awk book! There is a workaround. Turn all the patterns into the $0~/re/ form. This seems to restore generality in the use of parentheses. But it was an odd oversight to let this creep in. What sort of test suites are used that don't check parsing? And as end users are we, and our system administrators, unaware of upgrades that correct this rather glaring fault? ----------------------- Hylton Boothroyd Janet: h.boothroyd@uk.ac.warwick.cu Warwick Business School Darpa: h.boothroyd%cu.warwick.ac.uk@relay-nsfnet.ac.uk University of Warwick Uucp: h.boothroyd%sol@warwick.uucp COVENTRY Earn/Bitnet: h.boothroyd%uk.ac.warwick.cu@UKACRL England CV4 7AL Phone: +44 203 523523 Extension 2428 -----------------------