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Bug with qr// and multiline #4474

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p5pRT opened this issue Oct 3, 2001 · 2 comments
Closed

Bug with qr// and multiline #4474

p5pRT opened this issue Oct 3, 2001 · 2 comments
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distro-Linux type-regex

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@p5pRT
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p5pRT commented Oct 3, 2001

Migrated from rt.perl.org#7781 (status was 'resolved')

Searchable as RT7781$
@p5pRT
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p5pRT commented Oct 3, 2001

From neilw@ActiveState.com

This bug has to do with qr//m not working correctly. Here are two one-liners
which demonstrate the problem​:

$ perl -wle '$a = "begin\nend"; $a =~ /^(begin)$/m; print $1'
begin
$ perl -wle '$a = "begin\nend"; $a =~ qr/^(begin)$/m; print $1'
Use of uninitialized value in print at -e line 1.

This means that somehow, the qr// operator, when combined with the 'm'
modifier, does not execute properly. It doesn't forget all about the 'm'
operator, though​:

$ perl -MData​::Dumper -we 'print Dumper qr/^(begin)$/m'
$VAR1 = qr/(?m-xis​:^(begin)$)/;

And even more strange, we can actually get the correct result by substituting
the more explicit regex back in for the old one​:

$ perl -wle '$a = "begin\nend"; $a =~ qr/(?m-xis​:^(begin)$)/; print $1'
begin

So there's only a problem with the trailing modifiers. This begs the question​:
does this affect any other modifiers? Apparently not, at least for the most
obvious ones​:

'i' modifier​:
$ perl -wle '$a = "BeGiN"; $a =~ qr/^(begin)$/i; print $1'
BeGiN

'x' modifier​:
$ perl -wle '$a = "begin"; $a =~ qr/^ ( begin ) $/x; print $1'
begin

's' modifier​:
$ perl -wle '$a = "begin\nend"; $a =~ qr/^(be.+nd)$/s; print $1'
begin
end

Perl Info 

Flags:
    category=core
    severity=medium

Site configuration information for perl v5.6.1:

Configured by daves at Mon Aug 20 15:53:26 PDT 2001.

Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration:
  Platform:
    osname=linux, osvers=2.2.17, archname=i686-linux-thread-multi
    uname='linux gimlet 2.2.17 #1 sun jun 25 09:24:41 est 2000 i686 unknown '
    config_args='-des -Dcc=gcc -Dcf_by=ActiveState -Dcf_email=ActivePerl@ActiveState.com -Uinstallusrbinperl -Ud_sigsetjmp -Dusethreads -Duseithreads -Dinc_version_list=5.6.0/$archname 5.6.0 -Dprefix=/usr/lang/perl/AP629'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define usemultiplicity=define
    useperlio=undef d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
  Compiler:
    cc='gcc', ccflags ='-DUSE_REENTRANT_API -D_POSIX_C_SOURCE=199506L -D_REENTRANT -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    optimize='-O2',
    cppflags='-DUSE_REENTRANT_API -D_POSIX_C_SOURCE=199506L -D_REENTRANT -fno-strict-aliasing -I/usr/local/include'
    ccversion='', gccversion='2.95.2 20000220 (Debian GNU/Linux)', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8
    alignbytes=4, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lndbm -ldb -ldl -lm -lpthread -lc -lposix -lcrypt -lutil
    perllibs=-lnsl -ldl -lm -lpthread -lc -lposix -lcrypt -lutil
    libc=/lib/libc-2.1.3.so, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    ACTIVEPERL_LOCAL_PATCHES_ENTRY


@INC for perl v5.6.1:
    /usr/lang/perl/AP629/lib/5.6.1/i686-linux-thread-multi
    /usr/lang/perl/AP629/lib/5.6.1
    /usr/lang/perl/AP629/lib/site_perl/5.6.1/i686-linux-thread-multi
    /usr/lang/perl/AP629/lib/site_perl/5.6.1
    /usr/lang/perl/AP629/lib/site_perl
    .


Environment for perl v5.6.1:
    HOME=/home/neilw
    LANG=en_US
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/usr/lang/perl/AP629/bin:/usr/lang/perl/AP626/bin:/usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/home/neilw/bin
    PERL_BADLANG (unset)
    SHELL=/bin/bash

@p5pRT
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p5pRT commented Nov 4, 2004

@smpeters - Status changed from 'open' to 'resolved'

@p5pRT p5pRT closed this as completed Nov 4, 2004
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