perl -d hanging on some input

bsb has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: perl -d hanging on some input by jeffa (Bishop) on Feb 27, 2004 at 01:53 UTC
`[jeffa@junk-box jeffa]$ perl -de 1 [...] DB<1> ($a,$b) = chop($c='hello'); DB<2> print join'-',$a,$b; o- DB<3> ($a,$b) = 'hello' =~ /(he)(l{2}o)/; DB<4> print join'-',$a,$b; he-llo` [download] No problems for me (v5.6.1 built for i386-linux) ... i think we are going to need more info ... UPDATE: yep ... time to get my eyes examined ... bsb, when i ran the second i received a shiny `Signal SEGV` :/ jeffa L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)	[reply] [d/l]
Re: Re: perl -d hanging on some input by bsb (Priest) on Feb 27, 2004 at 02:16 UTC
The critical difference: `($a,$b) = chop($c='hello'); # $b ($a, b) = chop($c='hello'); # just b -> hang` [download] Please try the second and let me know what happens.	[reply] [d/l]
Re: perl -d hanging on some input by BrowserUk (Patriarch) on Feb 27, 2004 at 02:18 UTC
It's probably a typo, and I can't see how it would produce the effect you describe anyway, but you have a bare word in your list assignment. ($a,b) = .... That gives me `DB<2> ($a,b) = chop Can't modify constant item in list assignment at (eval 6)[c DB<3>` [download] Examine what is said, not who speaks. "Efficiency is intelligent laziness." -David Dunham "Think for yourself!" - Abigail Timing (and a little luck) are everything!	[reply] [d/l]
Re: Re: perl -d hanging on some input by bsb (Priest) on Feb 27, 2004 at 02:24 UTC
Which version/platform? The "($a,b) = chop" test hangs for me. Note also that these work fine: `perl -e '($a,b) = chop' perl -de '($a,b) = chop' # the pressing "c" to continue` [download]	[reply] [d/l]
Re: Re: Re: perl -d hanging on some input by BrowserUk (Patriarch) on Feb 27, 2004 at 02:44 UTC
P:\test>perl -v This is perl, v5.8.2 built for MSWin32-x86-multi-thread (with 25 registered patches, see perl -V for more detail) Copyright 1987-2003, Larry Wall Binary build 808 provided by ActiveState Corp. http://www.ActiveState. +com ActiveState is a division of Sophos. Built Dec 9 2003 10:19:40 Perl may be copied only under the terms of either the Artistic License + or the GNU General Public License, which may be found in the Perl 5 source ki +t. Complete documentation for Perl, including FAQ lists, should be found +on this system using `man perl' or `perldoc perl'. If you have access to + the Internet, point your browser at http://www.perl.com/, the Perl Home Pa +ge. P:\test>perl -de1 Loading DB routines from perl5db.pl version 1.22 Editor support available. Enter h or `h h' for help, or `perldoc perldebug' for more help. main::(-e:1): 1 DB<1> ($a,b) = chop Can't modify constant item in list assignment at (eval 5)[c:/Perl/lib/ +perl5db.pl:618] line 2, at EOF DB<2> [download] Examine what is said, not who speaks. "Efficiency is intelligent laziness." -David Dunham "Think for yourself!" - Abigail Timing (and a little luck) are everything!	[reply] [d/l]
Re: Re: Re: perl -d hanging on some input by waswas-fng (Curate) on Feb 27, 2004 at 05:04 UTC
works fine for me too... [osx:share/mysql/sql-bench] me% perl -V Summary of my perl5 (revision 5.0 version 8 subversion 1 RC3) configur +ation: Platform: osname=darwin, osvers=7.0, archname=darwin-thread-multi-2level uname='darwin hampsten 7.0 darwin kernel version 6.0: fri jul 25 1 +6:58:41 pdt 2003; root:xnu-344.frankd.rootsxnu-344.frankd~objrelease_ +ppc power macintosh powerpc ' config_args='-ds -e -Dprefix=/usr -Dccflags=-g -pipe -Dldflags=- +Dman3ext=3pm -Duseithreads -Duseshrplib' hint=recommended, useposix=true, d_sigaction=define usethreads=define use5005threads=undef useithreads=define usemulti +plicity=define useperlio=define d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='cc', ccflags ='-g -pipe -pipe -fno-common -DPERL_DARWIN -no-cp +p-precomp -fno-strict-aliasing -I/usr/local/include', ... [download] `main::(-e:1): 1 DB<1> ($a,b) = chop Can't modify constant item in list assignment at (eval 5)[/System/Libr +ary/Perl/5.8.1/perl5db.pl:618] line 2, at EOF` [download] -Waswas	[reply] [d/l] [select]