From chris@ex-parrot.com

Created by chris@caesious.cold.local

In the documentation for the POSIX module, there is the statement,

  pipe Create an interprocess channel. This returns file descriptors like those returned by
  "POSIX​::open".

  ($fd0, $fd1) = POSIX​::pipe();
  POSIX​::write( $fd0, "hello", 5 );
  POSIX​::read( $fd1, $buf, 5 );

  See also "pipe" in perlfunc.

This is wrong. $fd0 is writable, $fd1 is readable. The file
descriptors in the POSIX​::write and POSIX​::read functions
should be exchanged as appropriate.

Flags:
    category=docs
    severity=medium

This perlbug was built using Perl v5.8.5 - Tue Aug 10 17:59:43 BST 2004
It is being executed now by  Perl v5.8.5 - Tue Aug 10 17:47:29 BST 2004.

Site configuration information for perl v5.8.5:

Configured by chris at Tue Aug 10 17:47:29 BST 2004.

Summary of my perl5 (revision 5 version 8 subversion 5) configuration:
  Platform:
    osname=linux, osvers=2.4.25, archname=i686-linux
    uname='linux caesious.cold.local 2.4.25 #5 smp thu jul 15 19:59:33 bst 2004 i686 unknown '
    config_args='-d'
    hint=recommended, useposix=true, d_sigaction=define
    usethreads=undef use5005threads=undef useithreads=undef usemultiplicity=undef
    useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='cc', ccflags ='-fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm',
    optimize='-O2',
    cppflags='-fno-strict-aliasing -pipe -I/usr/local/include -I/usr/include/gdbm'
    ccversion='', gccversion='2.96 20000731 (Red Hat Linux 7.3 2.96-110)', 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='cc', ldflags =' -L/usr/local/lib'
    libpth=/usr/local/lib /lib /usr/lib
    libs=-lnsl -lndbm -lgdbm -ldl -lm -lcrypt -lutil -lc
    perllibs=-lnsl -ldl -lm -lcrypt -lutil -lc
    libc=/lib/libc-2.2.5.so, so=so, useshrplib=false, libperl=libperl.a
    gnulibc_version='2.2.5'
  Dynamic Linking:
    dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E'
    cccdlflags='-fpic', lddlflags='-shared -L/usr/local/lib'

Locally applied patches:
    


@INC for perl v5.8.5:
    /home/chris/software/useful/perllib
    /home/chris/software/useful/perllib
    /home/chris/software/useful/perllib
    /usr/local/lib/perl5/5.8.5/i686-linux
    /usr/local/lib/perl5/5.8.5
    /usr/local/lib/perl5/site_perl/5.8.5/i686-linux
    /usr/local/lib/perl5/site_perl/5.8.5
    /usr/local/lib/perl5/site_perl
    .


Environment for perl v5.8.5:
    HOME=/home/chris
    LANG (unset)
    LANGUAGE (unset)
    LD_LIBRARY_PATH (unset)
    LOGDIR (unset)
    PATH=/software/bin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/libexec:/usr/local/bin:/usr/local/libexec:/usr/X11R6/bin:/software/bin:/software/sbin:/software/scripts:/usr/games:/software/apps/mozilla:/software/apps/Acrobat4/bin:/software/exim-3.03/bin:/software/scheme-7.4/bin:/software/squid-2.2.STABLE5/bin:/software/freeciv-1.9.0/bin:/software/j2sdk1.4.1_01/bin:/home/chris/bin:/home/chris/bin:/home/chris/photos/bin:/home/chris/bin/caesious.cold.local
    PERL5LIB=:/home/chris/software/useful/perllib:/home/chris/software/useful/perllib:/home/chris/software/useful/perllib
    PERL_BADLANG (unset)
    SHELL=/bin/bash

From @rgs

chris@​ex-parrot.com (via RT) wrote​:

In the documentation for the POSIX module, there is the statement,

   pipe    Create an interprocess channel\.  This returns file descriptors like those returned by
           "POSIX​::open"\.

                   \($fd0\, $fd1\) = POSIX​::pipe\(\);
                   POSIX​::write\( $fd0\, "hello"\, 5 \);
                   POSIX​::read\( $fd1\, $buf\, 5 \);

           See also "pipe" in perlfunc\.

This is wrong. $fd0 is writable, $fd1 is readable. The file
descriptors in the POSIX​::write and POSIX​::read functions
should be exchanged as appropriate.

Good catch, I've done it as change 23518 to bleadperl.

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

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

From @schwern

On Fri, Nov 19, 2004 at 10​:48​:48AM +0100, Rafael Garcia-Suarez wrote​:

This is wrong. $fd0 is writable, $fd1 is readable. The file
descriptors in the POSIX​::write and POSIX​::read functions
should be exchanged as appropriate.

Good catch, I've done it as change 23518 to bleadperl.

If you call things $fd0 and $fd1 folks are going to get it wrong.

--- ext/POSIX/POSIX.pod 2004/11/19 19​:25​:52 1.1
+++ ext/POSIX/POSIX.pod 2004/11/19 19​:26​:23
@​@​ -955,9 +955,9 @​@​
Create an interprocess channel. This returns file descriptors like those
returned by C<POSIX​::open>.

- ($fd0, $fd1) = POSIX​::pipe();
- POSIX​::write( $fd1, "hello", 5 );
- POSIX​::read( $fd0, $buf, 5 );
+ my($read, $write) = POSIX​::pipe();
+ POSIX​::write( $write, "hello", 5 );
+ POSIX​::read( $read, $buf, 5 );

See also L<perlfunc/pipe>.

--
Michael G Schwern schwern@​pobox.com http​://www.pobox.com/~schwern/
And it's made from all-natural baby skin, so you know it's good for the
environment.
  http​://www.goats.com/archive/000606.html

From @petdance

On Fri, Nov 19, 2004 at 02​:28​:56PM -0500, Michael G Schwern (schwern@​pobox.com) wrote​:

If you call things $fd0 and $fd1 folks are going to get it wrong.

Yay Schwern!

See also my rant at http​://www.oreillynet.com/pub/wlg/4535

  Any variable that relies on a numeral to distinguish it from a
  similar variable needs to be refactored, immediately.

xoxo,
Andy

--
Andy Lester => andy@​petdance.com => www.petdance.com => AIM​:petdance

From @rgs

Michael G Schwern wrote​:

On Fri, Nov 19, 2004 at 10​:48​:48AM +0100, Rafael Garcia-Suarez wrote​:

This is wrong. $fd0 is writable, $fd1 is readable. The file
descriptors in the POSIX​::write and POSIX​::read functions
should be exchanged as appropriate.

Good catch, I've done it as change 23518 to bleadperl.

If you call things $fd0 and $fd1 folks are going to get it wrong.

--- ext/POSIX/POSIX.pod 2004/11/19 19​:25​:52 1.1
+++ ext/POSIX/POSIX.pod 2004/11/19 19​:26​:23

Thanks, applied as #23527.