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[perl #8826] Document '-' as the argument to open

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From:
James E Keenan via RT
Date:
December 31, 2011 05:45
Subject:
[perl #8826] Document '-' as the argument to open
Message ID:
rt-3.6.HEAD-14510-1325339098-1822.8826-15-0@perl.org
On Mon Mar 11 04:16:33 2002, tagunov@motor.ru wrote:
> This is a bug report for perl from "Anton Tagunov" <tagunov@motor.ru>
> generated with the help of perlbug 1.33 running under perl v5.7.3.
> 
> 
> -----------------------------------------------------------------
> Hello, developers!
> 
> I have discovered some peculiarities with '-' argument to open,
> and sthoenna@efn.org (Yitzchak Scott-Thoennes)  (bs"d) has confirmed
> that:
> 
> YST>...open V, '-' seems to be equivalent to
> YST>*V = *STDIN{IO}; close V then seems to do absolutely
> YST>nothing. close STDIN, on the other hand, closes the
> YST>in-file-pointer shared by V and STDIN.
> 

Reviewing this older ticket, I noticed that there was no code example
provided.  I wrote the following, but it does not seem to support the
original poster's contention that "close V then seems to do absolutely
nothing." (Using Perl 5.14.2 on Darwin/PPC.)

#####
$ cat 8826.pl
#!/usr/local/bin/perl
use strict;
use warnings;

open V, '-';
for (my $i=0; $i<=2; $i++) {
    my $line = <V>;
    print $line;
}
close V;

my $next_line = <V>;
print $next_line;

$ cat lines
alpha
beta
gamma
delta

$ cat lines | perl ./8826.pl
alpha
beta
gamma
readline() on closed filehandle V at ./8826.pl line 12.
Use of uninitialized value $next_line in print at ./8826.pl line 13.
#####

If the filehandle has indeed been closed, then there's no need for the
documentation patch the poster suggested.  Thoughts?

Thank you very much.
Jim Keenan

---
via perlbug:  queue: perl5 status: open
https://rt.perl.org:443/rt3/Ticket/Display.html?id=8826

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