From Norman.Azadian@swisscom.com

If the first characters of an open filename specification are whitespace,
the open fails without yielding a failure status. As I understand the first
two sentences of the 2nd paragraph on page 191 of the camel book, this
should not be the case. Here's a small program to illustrate the problem​:

  #!/usr/bin/perl -w
  #Illustrates a perl bug
  #According to the second paragraph on page 191 of the bible, leading
  #whitespace should not be a problem. Here it is shown to be.

  open OUTPUT, " | cat " || die;
  print OUTPUT "THIS LINE DOES NOT APPEAR\n";
  close OUTPUT;

  open OUTPUT, "| cat " || die;
  print OUTPUT "THIS LINE DOES APPEAR\n";
  close OUTPUT;

  exit 0;

Running this program yields (for me)​:

  print on closed filehandle main​::OUTPUT at pt.pl line 7.
  THIS LINE DOES APPEAR

Here's the output of my 'perl -V'​:

  Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration​:
  Platform​:
  osname=hpux, osvers=11.00, archname=PA-RISC2.0
  uname='hp-ux sbe1351 b.11.00 e 9000889 274894302 8-user license
'
  hint=previous, useposix=true, d_sigaction=define
  usethreads=undef useperlio=undef d_sfio=undef
  Compiler​:
  cc='cc', optimize='-O', gccversion=
  cppflags='-D_HPUX_SOURCE -Aa +DA2.0W'
  ccflags ='-D_HPUX_SOURCE -Aa +DA2.0W'
  stdchar='unsigned char', d_stdstdio=define, usevfork=false
  intsize=4, longsize=8, ptrsize=8, doublesize=8
  d_longlong=undef, longlongsize=, d_longdbl=define,
longdblsize=16
  alignbytes=8, usemymalloc=y, prototype=define
  Linker and Libraries​:
  ld='ld', ldflags ='+DA2.0W'
  libpth=/usr/lib/pa20_64
  libs=-lnsl -lgdbm -ldl -ldld -lm -lc
  libc=/usr/lib/pa20_64/libc.sl, so=sl, useshrplib=false,
libperl=libperl.a
  Dynamic Linking​:
  dlsrc=dl_hpux.xs, dlext=sl, d_dlsymun=undef, ccdlflags='-Wl,-E
-Wl,-B,deferred '
  cccdlflags='+z', lddlflags='-b'

  Characteristics of this binary (from libperl)​:
  Built under hpux
  Compiled at Feb 9 2000 11​:41​:29
  %ENV​:
 
PERLLIB="/mbc/mbc509/mbc509/lib/perl​:/mbc/mbc509/mbc509/lib/perl/PA-RISC2.0"
  @​INC​:
  /mbc/mbc509/mbc509/lib/perl
  /mbc/mbc509/mbc509/lib/perl/PA-RISC2.0
  /usr/local/perl5/lib/5.00503/PA-RISC2.0
  /usr/local/perl5/lib/5.00503
  /usr/local/perl5/lib/site_perl/5.005/PA-RISC2.0
  /usr/local/perl5/lib/site_perl/5.005
  .

NHA
Norman.Azadian@​Swisscom.com

From @pudge

At 13.14 +0200 2000.04.18, Norman.Azadian@​swisscom.com wrote​:

If the first characters of an open filename specification are whitespace,
the open fails without yielding a failure status.

No, it fails just fine, if you check it just fine.

As I understand the first
two sentences of the 2nd paragraph on page 191 of the camel book, this
should not be the case.

I think you are correct. The Camel says that first whitespace is stripped,
then the filename is checked, so according to that description, " | cat "
and "| cat" should be treated exactly the same. The question is whether or
not the Camel is correct in what Perl's behavior should be. I dunno.

open OUTPUT, " | cat " || die;

You are saying​:

  open OUTPUT, (" | cat " || die);

since " | cat" is always true, you will never die. You did read part of
page 191 in the Camel, but apparently not the admonition to use "or die"
instead of "|| die". :-)