From bod@compusol.com.au

When $/ is not defined, <> reads past EOF​:

  $ perl -0777ne 'print $ARGV, "​: ", length, "\n"' /etc/group
  /etc/group​: 191
  /etc/group​: 0
  $

Some trace output.

  $ truss -topen,read perl -0777ne '[...]' /etc/group
  [...]
  open("/etc/group", O_RDONLY, 0666) = 3
  read(3, " r o o t : : 0 : r o o t".., 8192) = 191
  read(3, 0x08063008, 8192) = 0
  /etc/group​: 191
  read(3, 0x08063008, 8192) = 0
  /etc/group​: 0
  read(3, 0x08063008, 8192) = 0
  $

This behaviour does not appear to be specific to ARGV, as similar
behaviour is exhibited by​:

  #!/usr/bin/perl
  undef $/;
  open G, '/etc/group';
  while (<G>) { print length, "\n" }
  __END__

Flags​:
  category=core
  severity=medium

Site configuration information for perl v5.6.0​:

Configured by bod at Fri Mar 24 11​:47​:21 EST 2000.

Summary of my perl5 (revision 5.0 version 6 subversion 0) configuration​:
  Platform​:
  osname=svr4, osvers=, archname=pentium-svr4
  uname='unix_system_v diablo 4.0 2 pentium p5eisa '
  config_args=''
  hint=recommended, useposix=true, d_sigaction=define
  usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
  useperlio=undef d_sfio=undef uselargefiles=define
  use64bitint=undef use64bitall=undef uselongdouble=undef usesocks=undef
  Compiler​:
  cc='/usr/local/bin/gcc', optimize='-O2', gccversion=2.8.0
  cppflags=''
  ccflags =''
  stdchar='unsigned char', d_stdstdio=define, usevfork=false
  intsize=4, longsize=4, ptrsize=4, doublesize=8
  d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12
  ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=4
  alignbytes=4, usemymalloc=y, prototype=define
  Linker and Libraries​:
  ld='/usr/local/bin/gcc', ldflags =''
  libpth=/usr/local/lib /usr/lib /usr/ccs/lib
  libs=-lsocket -lnsl -lgdbm -ldb -ldl -lm -ldes -lc -ldbm
  libc=, so=so, useshrplib=true, libperl=libperl.so
  Dynamic Linking​:
  dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags=' '
  cccdlflags='-fPIC', lddlflags='-shared'

Locally applied patches​:
 

@​INC for perl v5.6.0​:
  /usr/local/lib/perl5/5.6.0/pentium-svr4
  /usr/local/lib/perl5/5.6.0
  /usr/local/lib/perl5/site_perl/5.6.0/pentium-svr4
  /usr/local/lib/perl5/site_perl/5.6.0
  /usr/local/lib/perl5/site_perl
  .

Environment for perl v5.6.0​:
  HOME=/home/bod
  LANG (unset)
  LANGUAGE (unset)
  LC_CTYPE=en_AU
  LD_LIBRARY_PATH=/usr/local/lib​:/usr/X11R6/lib
  LOGDIR (unset)
  PATH=/home/bod/bin​:/usr/local/bin​:/usr/bin​:/usr/ucb​:/usr/X11R6/bin​:/home/venture/bin​:
  PERL_BADLANG (unset)
  SHELL=/bin/ksh

From [Unknown Contact. See original ticket]

"Brendan O'Dea" <bod@​compusol.com.au> wrote

When $/ is not defined, <> reads past EOF​:

This a known bug [ID 20000627.003], which has been fixed in the
development version, so should be mended in perl5.6.1.

If you can't wait for perl5.6.1, you can find the patch at

http​://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2000-06/msg00751.html

Mike Guy