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[ID 20010703.009] Freaky action at a distance with $]

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Simon Cozens
July 3, 2001 10:15
[ID 20010703.009] Freaky action at a distance with $]
Message ID:
This is a bug report for perl from,
generated with the help of perlbug 1.33 running under perl v5.6.1.

[Please enter your report here]

This goes right through up to bleadperl. It's probably a Don't Do
That, Then bug, but...

 % perl -le '$]++'
 Modification of a read-only value attempted at -e line 1.

Fair enough. Let's defeat it!
 % perl -le '$main::{q/]/}++'
 % perl -le '$main::{q/]/}++; print $]'
 Modification of a read-only value attempted at -e line 1.


 % perl -le '$main::{q/]/}++; exit; print $]'
 Modification of a read-only value attempted at -e line 1.

Oh, come on.

 % perl -le 'eval q| $main::{q/]/}++;|; print $@'

 % perl -le 'eval q| $main::{q/]/}++;|; print $@; exit; print $]'
 Modification of a read-only value attempted at (eval 1) line 1.

The mere presence of another reference to $] during compilation
makes $main::{q/]}++ into a syntax error. I have a vague feeling
this has something to do with GV resolution of special variables

 % perl -le 'print $main::{q/]/};'          

 % perl -le 'print $]; print $main::{q/]/}; print ${$main::{q/]/}}'

Ooh, $] has found its way into main:: !

[Please do not change anything below this line]
Site configuration information for perl v5.6.1:

Configured by bod at Mon May 28 15:16:04 EST 2001.

Summary of my perl5 (revision 5.0 version 6 subversion 1) configuration:
    osname=linux, osvers=2.4.4, archname=i386-linux
    uname='linux duende 2.4.4 #1 thu may 17 10:50:53 est 2001 i686 unknown '
    config_args='-Dccflags=-DDEBIAN -Dcccdlflags=-fPIC -Darchname=i386-linux -Dprefix=/usr -Dprivlib=/usr/share/perl/5.6.1 -Darchlib=/usr/lib/perl/5.6.1 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/perl5 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.6.1 -Dsitearch=/usr/local/lib/perl/5.6.1 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Uusesfio -Dotherlibdirs=/usr/lib/perl5/5.6:/usr/lib/perl5/5.005 -Duseshrplib -Dd_dosuid -des'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=undef d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    cc='cc', ccflags ='-DDEBIAN -fno-strict-aliasing -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64',
    cppflags='-DDEBIAN -fno-strict-aliasing -I/usr/local/include'
    ccversion='', gccversion='2.95.4 20010506 (Debian prerelease)', 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='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lgdbm -ldbm -ldb -ldl -lm -lc -lcrypt
    perllibs=-ldl -lm -lc -lcrypt
    libc=/lib/, so=so, useshrplib=true,
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:

@INC for perl v5.6.1:

Environment for perl v5.6.1:
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PERL_BADLANG (unset)

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