Bug in IO::Handle method ioctl

[p5pRT]

Migrated from rt.perl.org#2109 (status was 'resolved')

Searchable as RT2109$

[p5pRT]

From private@claudio.ch

Created by private@claudio.ch

my $file=new IO​::File;
... correct open of file ...
$file->ioctl(someReadOP,$value);

does not work, while ioctl($file,someReadOp,$value) does.

This is ioctl in IO​::Handle.pm

560​: sub ioctl {
561​: @​_ == 3 || croak 'usage​: $io->ioctl( OP, VALUE );';
562​: my ($io, $op, $val) = @​_;
563​: my $r = ioctl($io, $op, $val);
564​: defined $r && $r eq "0 but true" ? 0 : $r;
565​: }

The $val passed to ioctl in line 563 is a local variable because
of the declaration in line 562. So any ioctl which reads a value
will fill in $val instead of the parameter passed to $file->ioctl.

To fix this, line 563 has to be changed into​:

  my $r = ioctl($io, $op, $_[2]);

This works (tested) because $_[2] is really the 2nd parameter
passed to $file->ioctl(someReadOp,$value).

Perl Info

Site configuration information for perl 5.00503:

Configured by claudio at Sat Nov 13 01:05:54 Local time zone must be set--see
zic
 manual page 1999.

Summary of my perl5 (5.0 patchlevel 5 subversion 3) configuration:
  Platform:
    osname=linux, osvers=2.2.13, archname=ppc-linux-thread
    uname='linux pb.claudio.ch 2.2.13 #1 tue oct 12 22:10:46 cest 1999 ppc
unknow
n '
    hint=previous, useposix=true, d_sigaction=define
    usethreads=define useperlio=undef d_sfio=undef
  Compiler:
    cc='cc', optimize='-O2', gccversion=egcs-2.91.66 19990314 (egcs-1.1.2
release
)
    cppflags='-D_REENTRANT -Dbool=char -DHAS_BOOL'
    ccflags ='-D_REENTRANT -Dbool=char -DHAS_BOOL'
    stdchar='char', d_stdstdio=undef, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=8
    alignbytes=8, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='cc', ldflags =''
    libpth=/usr/lib
    libs=-lnsl -lndbm -ldb -ldl -lm -lpthread -lc -lposix -lcrypt
    libc=, so=so, useshrplib=false, libperl=libperl.a
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-rdynamic'
    cccdlflags='-fpic', lddlflags='-shared'

Locally applied patches:
    


@INC for perl 5.00503:
    /opt/perl-5.005_03/lib/5.00503/ppc-linux-thread
    /opt/perl-5.005_03/lib/5.00503
    /opt/perl-5.005_03/lib/site_perl/5.005/ppc-linux-thread
    /opt/perl-5.005_03/lib/site_perl/5.005
    .


Environment for perl 5.00503:
    HOME=/home/claudio
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH=/usr/lib
    LOGDIR (unset)
    PATH=/usr/bin
    PERL_BADLANG (unset)
    SHELL=/usr/bin/bash


-- 
Claudio Nieder, Kanalweg 1, CH-8610 Uster ,'`.,'`.,'`.,'`.,'`.,'`.,'`
mailto:private@claudio.ch http://www.claudio.ch phone:+41 79 357 6743

[p5pRT]

From [Unknown Contact. See original ticket]

Why would you use IO​::Handle's ioctl function!?
Why isn't this a function call? I see no reason to
cloak all possible perl I/O functions in method calls.
There's no benefit to writing

  FH->ioctl(...)
over
  ioctl(FH, ...)

--tom

[p5pRT]

From The RT System itself

Hi,

Why would you use IO​::Handle's ioctl function!?
Why isn't this a function call? I see no reason to
cloak all possible perl I/O functions in method calls.
There's no benefit to writing

FH\->ioctl\(\.\.\.\)

Because I got used to do my $file=new IO​::File; $file->open
$file->getline etc.

But I could very well live with an IO​::Handle who doesn't implement
any method except new, and use my $file=new IO​::File; open($file)
<$file> etc. if that is thought to be the preferred way of doing it.

I just think it's bad when $file->ioctl() looks like if it would
work, but then doesn't fully. Either fix it, or throw it away.

  claudio
--
Claudio Nieder, Kanalweg 1, CH-8610 Uster ,'`.,'`.,'`.,'`.,'`.,'`.,'`
mailto​:private@​claudio.ch http​://www.claudio.ch phone​:+41 79 357 6743