<FH> producing "Bad file descriptor"

[p5pRT]

Migrated from rt.perl.org#34412 (status was 'resolved')

Searchable as RT34412$

[p5pRT]

From lace@jankratochvil.net

Created by lace@jankratochvil.net

BAD​:
"vanilla Perl-5.8.6" or "Fedora Core 3 perl-5.8.5-9"​:
$ echo a >/tmp/a;perl -e 'open FH,"/tmp/a" or die;$!=undef();my $line=&lt;FH&gt;;print "$!​:$line\n";'
Bad file descriptor​:a

GOOD​:
"Red Hat 7.2 Perl-5.6.1" or other old Perls​:
$ echo a >/tmp/a;perl -e 'open FH,"/tmp/a" or die;$!=undef();my $line=&lt;FH&gt;;print "$!​:$line\n";'
:a

Last CPAN "File​::Grep" is several years failing "make test" due to it.
Error will not happend if $/ ne "\n";

Thanks for the great tool; looking for 6.

Perl Info

Flags:
    category=core
    severity=medium

This perlbug was built using Perl v5.8.5 in the Red Hat build system.
It is being executed now by Perl v5.8.5 - Tue Oct 12 12:44:18 EDT 2004.

Site configuration information for perl v5.8.5:

Configured by Red Hat, Inc. at Tue Oct 12 12:44:18 EDT 2004.

Summary of my perl5 (revision 5 version 8 subversion 5) configuration:
  Platform:
    osname=linux, osvers=2.4.21-14.elsmp, archname=i386-linux-thread-multi
    uname='linux tweety.build.redhat.com 2.4.21-14.elsmp #1 smp wed apr 14 18:55:47 edt 2004 i686 i686 i386 gnulinux '
    config_args='-des -Doptimize=-O2 -g -pipe -m32 -march=i386 -mtune=pentium4 -Dversion=5.8.5 -Dmyhostname=localhost -Dperladmin=root@localhost -Dcc=gcc -Dcf_by=Red Hat, Inc. -Dinstallprefix=/usr -Dprefix=/usr -Darchname=i386-linux -Dvendorprefix=/usr -Dsiteprefix=/usr -Duseshrplib -Dusethreads -Duseithreads -Duselargefiles -Dd_dosuid -Dd_semctl_semun -Di_db -Ui_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dman3ext=3pm -Duseperlio -Dinstallusrbinperl -Ubincompat5005 -Uversiononly -Dpager=/usr/bin/less -isr -Dinc_version_list=5.8.4 5.8.3 5.8.2 5.8.1 5.8.0'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=define use5005threads=undef useithreads=define usemultiplicity=define
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBUGGING -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm',
    optimize='-O2 -g -pipe -m32 -march=i386 -mtune=pentium4',
    cppflags='-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBUGGING -fno-strict-aliasing -pipe -I/usr/local/include -I/usr/include/gdbm'
    ccversion='', gccversion='3.4.2 20041006 (Red Hat 3.4.2-5)', 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, prototype=define
  Linker and Libraries:
    ld='gcc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lpthread -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc
    libc=/lib/libc-2.3.3.so, so=so, useshrplib=true, libperl=libperl.so
    gnulibc_version='2.3.3'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E -Wl,-rpath,/usr/lib/perl5/5.8.5/i386-linux-thread-multi/CORE'
    cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    


@INC for perl v5.8.5:
    /home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl/5.8.5
    /home/lace/lib/perl5/site_perl/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl
    /home/lace/lib/perl5/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/5.8.5
    /home/lace/lib/perl5/i386-linux-thread-multi
    /home/lace/lib/perl5
    /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.5
    /usr/lib/perl5/site_perl/i386-linux-thread-multi
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/5.8.5
    /usr/lib/perl5/i386-linux-thread-multi
    /usr/lib/perl5
    /home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl/5.8.5
    /home/lace/lib/perl5/site_perl/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl
    /home/lace/lib/perl5/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/5.8.5
    /home/lace/lib/perl5/i386-linux-thread-multi
    /home/lace/lib/perl5
    /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.5
    /usr/lib/perl5/site_perl/i386-linux-thread-multi
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/5.8.5
    /usr/lib/perl5/i386-linux-thread-multi
    /usr/lib/perl5
    /home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl/5.8.5
    /home/lace/lib/perl5/site_perl/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl
    /home/lace/lib/perl5/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/5.8.5
    /home/lace/lib/perl5/i386-linux-thread-multi
    /home/lace/lib/perl5
    /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.5
    /usr/lib/perl5/site_perl/i386-linux-thread-multi
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/5.8.5
    /usr/lib/perl5/i386-linux-thread-multi
    /usr/lib/perl5
    /home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl/5.8.5
    /home/lace/lib/perl5/site_perl/i386-linux-thread-multi
    /home/lace/lib/perl5/site_perl
    /home/lace/lib/perl5/5.8.5/i386-linux-thread-multi
    /home/lace/lib/perl5/5.8.5
    /home/lace/lib/perl5/i386-linux-thread-multi
    /home/lace/lib/perl5
    /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.5
    /usr/lib/perl5/site_perl/i386-linux-thread-multi
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/5.8.5
    /usr/lib/perl5/i386-linux-thread-multi
    /usr/lib/perl5
    /usr/lib/perl5/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/5.8.5
    /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.4/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.3/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.2/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.1/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.0/i386-linux-thread-multi
    /usr/lib/perl5/site_perl/5.8.5
    /usr/lib/perl5/site_perl/5.8.4
    /usr/lib/perl5/site_perl/5.8.3
    /usr/lib/perl5/site_perl/5.8.2
    /usr/lib/perl5/site_perl/5.8.1
    /usr/lib/perl5/site_perl/5.8.0
    /usr/lib/perl5/site_perl
    /usr/lib/perl5/vendor_perl/5.8.5/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.4/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.3/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.2/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.1/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.0/i386-linux-thread-multi
    /usr/lib/perl5/vendor_perl/5.8.5
    /usr/lib/perl5/vendor_perl/5.8.4
    /usr/lib/perl5/vendor_perl/5.8.3
    /usr/lib/perl5/vendor_perl/5.8.2
    /usr/lib/perl5/vendor_perl/5.8.1
    /usr/lib/perl5/vendor_perl/5.8.0
    /usr/lib/perl5/vendor_perl
    .


Environment for perl v5.8.5:
    HOME=/home/lace
    LANG=en_US.UTF-8
    LANGUAGE (unset)
    LC_COLLATE=C
    LD_LIBRARY_PATH=/home/lace/lib:/opt/sfw/lib:/home/lace/lib:/opt/sfw/lib:/home/lace/lib:/opt/sfw/lib:/home/lace/lib:/opt/sfw/lib
    LOGDIR (unset)
    PATH=/home/lace/bin:/usr/local/bin:/opt/sfw/bin:/usr/sbin:/sbin:/usr/dist/exe:/opt/SUNWspro/bin:/home/lace/bin:/usr/local/bin:/opt/sfw/bin:/usr/sbin:/sbin:/usr/dist/exe:/opt/SUNWspro/bin:/home/lace/bin:/usr/local/bin:/opt/sfw/bin:/usr/sbin:/sbin:/usr/dist/exe:/opt/SUNWspro/bin:/home/lace/bin:/usr/local/bin:/opt/sfw/bin:/usr/sbin:/sbin:/usr/dist/exe:/opt/SUNWspro/bin:/usr/kerberos/bin:/usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin
    PERLLIB=/home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl/5.8.5:/home/lace/lib/perl5/site_perl/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl:/home/lace/lib/perl5/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/5.8.5:/home/lace/lib/perl5/i386-linux-thread-multi:/home/lace/lib/perl5:/usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/site_perl/5.8.5:/usr/lib/perl5/site_perl/i386-linux-thread-multi:/usr/lib/perl5/site_perl:/usr/lib/perl5/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/5.8.5:/usr/lib/perl5/i386-linux-thread-multi:/usr/lib/perl5:/home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl/5.8.5:/home/lace/lib/perl5/site_perl/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl:/home/lace/lib/perl5/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/5.8.5:/home/lace/lib/perl5/i386-linux-thread-multi:/home/lace/lib/perl5:/usr/lib/perl5/site_perl/5.8.5/i386-linux!
 -thread-multi:/usr/lib/perl5/site_perl/5.8.5:/usr/lib/perl5/site_perl/i386-linux-thread-multi:/usr/lib/perl5/site_perl:/usr/lib/perl5/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/5.8.5:/usr/lib/perl5/i386-linux-thread-multi:/usr/lib/perl5:/home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl/5.8.5:/home/lace/lib/perl5/site_perl/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl:/home/lace/lib/perl5/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/5.8.5:/home/lace/lib/perl5/i386-linux-thread-multi:/home/lace/lib/perl5:/usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/site_perl/5.8.5:/usr/lib/perl5/site_perl/i386-linux-thread-multi:/usr/lib/perl5/site_perl:/usr/lib/perl5/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/5.8.5:/usr/lib/perl5/i386-linux-thread-multi:/usr/lib/perl5:/home/lace/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/home/lace/lib/perl5/site_perl/5.8.5:/home/lace/lib/perl5/site_perl/i386-linux-t!
 hread-multi:/home/lace/lib/perl5/site_perl:/home/lace/lib/perl!
 5/5.8.5/
i386-linux-thread-multi:/home/lace/lib/perl5/5.8.5:/home/lace/lib/perl5/i386-linux-thread-multi:/home/lace/lib/perl5:/usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/site_perl/5.8.5:/usr/lib/perl5/site_perl/i386-linux-thread-multi:/usr/lib/perl5/site_perl:/usr/lib/perl5/5.8.5/i386-linux-thread-multi:/usr/lib/perl5/5.8.5:/usr/lib/perl5/i386-linux-thread-multi:/usr/lib/perl5
    PERL_BADLANG (unset)
    PERL_MM_OPT=PERL=/home/lace/bin/perlilib PREFIX=/home/lace
    SHELL=/bin/bash

[p5pRT]

From perl5-porters@ton.iguana.be

In article <rt-3.0.11-34412-108744.6.00529762057072@​perl.org>,
  "lace@​jankratochvil.net (via RT)" <perlbug-followup@​perl.org> writes​:

BAD​:
"vanilla Perl-5.8.6" or "Fedora Core 3 perl-5.8.5-9"​:
$ echo a >/tmp/a;perl -e 'open FH,"/tmp/a" or die;$!=undef();my $line=&lt;FH&gt;;print "$!​:$line\n";'
Bad file descriptor​:a

Not a bug really. $! is only meaningful immediately after a system or library
call *failed*. Succesful calls are in principle allowed to change $!
any way they like.

Having said that there doesn't seem to be a good reason for $! to
get set here though. But tracking the base cause down would be mainly for
curiosity.

[p5pRT]

The RT System itself - Status changed from 'new' to 'open'

[p5pRT]

From lace@jankratochvil.net

Hi Ton,

On Sat, 12 Mar 2005 18​:19​:33 +0100, (Ton Hospel) via RT wrote​:
...

Not a bug really. $! is only meaningful immediately after a system or library
call *failed*. Succesful calls are in principle allowed to change $!
any way they like.

OK, fully understood. In fact I am really a moron as I write code aware of it.

Going to fix File​::Grep.

Thanks,
Lace

[p5pRT]

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

[p5pRT]

From japhy@perlmonk.org

On Mar 12, Ton Hospel said​:

In article <rt-3.0.11-34412-108744.6.00529762057072@​perl.org>,
"lace@​jankratochvil.net (via RT)" <perlbug-followup@​perl.org> writes​:

BAD​:
"vanilla Perl-5.8.6" or "Fedora Core 3 perl-5.8.5-9"​:
$ echo a >/tmp/a;perl -e 'open FH,"/tmp/a" or die;$!=undef();my $line=&lt;FH&gt;;print "$!​:$line\n";'
Bad file descriptor​:a

Not a bug really. $! is only meaningful immediately after a system or library
call *failed*. Succesful calls are in principle allowed to change $!
any way they like.

Having said that there doesn't seem to be a good reason for $! to
get set here though. But tracking the base cause down would be mainly for
curiosity.

I contacted the author of the module in question. After looking at his
code, he has​:

  eval { $line = <$fh> };
  if ($! || $@​) { ... }

I told him he should local()ize $! and $@​ before doing the eval { }.

--
Jeff "japhy" Pinyan % How can we ever be the sold short or
RPI Acacia Brother #734 % the cheated, we who for every service
http​://japhy.perlmonk.org/ % have long ago been overpaid?
http​://www.perlmonks.org/ % -- Meister Eckhart

[p5pRT]

From lace@jankratochvil.net

Hi,

On Mon, 14 Mar 2005 16​:47​:01 +0100, japhy@​perlmonk.org via RT wrote​:
...

I contacted the author of the module in question. After looking at his
code, he has​:

eval { $line = <$fh> };
if ($! || $@​) { ... }

I told him he should local()ize $! and $@​ before doing the eval { }.

I think local() is not enough - still the successful <$fh> would set $! and
the 'if ($! || $@​)' below would falsely follow the fail code path.

Anyway I already sent him the [attached] patch. He has not replied, though.
Please forward it to the appropriate person to make it to CPAN.
I already had such problems in the past with unresponsible buggy CPAN module
authors. :-?

Thanks,
Lace

[p5pRT]

From lace@jankratochvil.net

Hi,

please apply the patch to fix File​::Grep functionality (with failing "make
test") with recent Perls such as 5.8.5 or 5.8.6.

Regards,
Lace

[p5pRT]

From lace@jankratochvil.net

File-Grep-0.01-Grep.pm-failfail.patch

--- File-Grep-0.01/Grep.pm-orig	2002-01-26 03:32:57.000000000 +0100
+++ File-Grep-0.01/Grep.pm	2005-03-12 18:46:09.052150615 +0100
@@ -57,13 +57,13 @@
       $openfile = 0;
     }
     my $line;
-    eval { $line = <$fh> };
-    if ( $! || $@ ) {
-      if ( $@ ) {
-	!$SILENT and carp "Cannot use file '$file' for fgrep: $@";
-      } else {
-	!$SILENT and carp "Cannot use file '$file' for fgrep: $!";
-      }
+    # Be aware $! may be modified in any way if <$fh> does not fail.
+    my $err;
+    eval { defined($line = <$fh>) or $err = "$!"; };
+    # $@ is more important than $!
+    $err = $@ if $@;
+    if ( $err ) {
+      !$SILENT and carp "Cannot use file '$file' for fgrep: $err";
       last;
     } else {
       while ( defined( $line ) ) {

[p5pRT]

From @nwc10

On Mon, Mar 14, 2005 at 08​:25​:34PM +0100, Jan Kratochvil wrote​:

Anyway I already sent him the [attached] patch. He has not replied, though.
Please forward it to the appropriate person to make it to CPAN.
I already had such problems in the past with unresponsible buggy CPAN module
authors. :-?

You've already forwarded it to the appropriate person - the author.
CPAN is just an archive - it can't force authors to be responsive, even
when people send them well formatted code.

There's a section of the CPAN FAQ which is probably relevant

  "How do I go about maintaining a module when the author is unresponsive?"
  http​://www.cpan.org/misc/cpan-faq.html#How_maintain_module

Nicholas Clark