From tagunov@motor.ru

This is a bug report for perl from "Anton Tagunov" <tagunov@​motor.ru>,
generated with the help of perlbug 1.33 running under perl v5.7.3.

Hello, all! Trying to figure out if closing ARGV inside while(<>)
could close STDIN have found that the following four samples
work all differently (the names of the testcases are arbitrary,
I do not think one behaviour to be good while other bad, I do
not know which one is preferable :-)

good.pl----------
use strict; use warnings;
#error​: readline() on closed filehandle ZZZ at good.pl line ..
@​ARGV = ( '<'.$0 );
unshift(@​ARGV, '-') unless @​ARGV;
while ($ARGV = shift @​ARGV) {
  open(ZZZ, $ARGV);
  while (<ZZZ>) {
  close ZZZ;
  print '.',$_;
  }
}

bad.pl------------
use strict; use warnings;
#prints one line and bails out
@​ARGV = ( '<'.$0 );
while (<>) {
  close ARGV;
  print '.',$_;
}

evil.pl------------
use strict; use warnings;
#prints _two_ lines
open STDIN, $0;
@​ARGV = ( '-' );
unshift(@​ARGV, '-') unless @​ARGV;
while ($ARGV = shift @​ARGV) {
  open(ARGV, $ARGV);
  while (<ARGV>) {
  close ARGV;
  print '.',$_;
  }
}

naughty.pl----------
use strict; use warnings;
# reads both @​ARGV and STDIN,
#
# related to
#
# '[ID 20020222.011]
# while(<>){close ARGV if eof; eof();}
# produces unexpected behavior'
#
# ?
open STDIN,'<'.$0;
@​ARGV = ( '<'.$0 );
unshift(@​ARGV, '-') unless @​ARGV;
while ($ARGV = shift @​ARGV) {
  open(ARGV, $ARGV);
  while (<ARGV>) {
  close ARGV;
  print '.',$_;
  }
}

Uff! What a fun, gentlemen! Do you like diversity? :-)

- Anton

Flags​:
  category=core
  severity=low

Site configuration information for perl v5.7.3​:

Configured by anthony at Wed Mar 6 00​:02​:07 2002.

Summary of my perl5 (revision 5 undef) configuration​:
  Platform​:
  osname=MSWin32, osvers=4.0, archname=MSWin32-x86-multi-thread
  uname=''
  config_args='undef'
  hint=recommended, useposix=true, d_sigaction=undef
  usethreads=undef use5005threads=undef useithreads=define usemultiplicity=define
  useperlio=define d_sfio=undef uselargefiles=undef usesocks=undef
  use64bitint=undef use64bitall=undef uselongdouble=undef
  usemymalloc=n, bincompat5005=undef
  Compiler​:
  cc='cl', ccflags ='-nologo -Gf -W3 -O1 -MD -DNDEBUG -DWIN32 -D_CONSOLE -DNO_STRICT -DPERL_IMPLICIT_CONTEXT
-DPERL_IMPLICIT_SYS
-DUSE_PERLIO -DPERL_MSVCRT_READFIX',
  optimize='-O1 -MD -DNDEBUG',
  cppflags='-DWIN32'
  ccversion='undef', gccversion='', gccosandvers='undef'
  intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
  d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
  ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=4
  alignbytes=8, prototype=define
  Linker and Libraries​:
  ld='link', ldflags ='-nologo -nodefaultlib -release -libpath​:"c​:\perl5047\lib\CORE" -machine​:x86'
  libpth=e​:\apps\ds40\VC\lib
  libs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib
oleaut32.lib
netapi32.lib uuid.lib wsock32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib
  perllibs=undef
  libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl57.lib
  Dynamic Linking​:
  dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
  cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -release -libpath​:"c​:\perl5047\lib\CORE" -machine​:x86'

Locally applied patches​:
  DEVEL15046

@​INC for perl v5.7.3​:
  c​:/perl15046/lib
  c​:/perl15046/site/lib
  .

Environment for perl v5.7.3​:
  HOME=C​:\
  LANG (unset)
  LANGUAGE (unset)
  LC_ALL=EN_US
  LD_LIBRARY_PATH (unset)
  LOGDIR (unset)
  PATH=E​:\apps\ibm\vaj\eab\bin;C​:\usr\local\bin\;e​:\Program
Files\ibm\gsk5\lib;E​:\APPS\ROSE\RATION1\NUTCROOT\bin;E​:\APPS\ROSE\RATION1\NUTCROOT\bin\x11;E​:\APPS\ROSE\RATION~1\NUTCROOT\mksnt;e​:\java\sun\java131\bin;e​:\apps\vbroker\jre\Bin;e​:\apps\vbroker\Bin;C​:\WINNT\system32;C​:\WINNT;c​:\util;E​:\apps\CacheSys\Bin;C​:\Program
Files\rksupport;C​:\WINNT\ton\bin;E​:\apps\rose\common;E​:\apps\rose\Rational
Test;E​:\apps\borland\delphi\Bin;E​:\apps\borland\delphi\Projects\Bpl;E​:\apps\ibm\IBM\IMNNQ;E​:\apps\ibm\db2p\BIN;E​:\apps\ibm\db2p\FUNCTION;E​:\apps\ibm\db2p\SAMPLES\REPL;E​:\apps\ibm\db2p\HELP;e​:\apps\ibm\websphere\bin
  PERL_BADLANG (unset)
  SHELL (unset)

@chorny - Status changed from 'open' to 'stalled'