Re: stderr, local block and redirection

Try my $output = ""; instead. And you may actually want to print something to STDERR inside the block.

#!/usr/bin/perl

use strict;
use warnings;

sub test_stderr {
        my $output = "";

        {
                open local(*STDERR), '>', \$output;
                print STDERR "CATCH ME IF YOU CAN\n";
        }

        print "\$output is '$output'\n" if $output;
}

test_stderr;
print STDERR "I'm not caught\n";
[download]

Update: Gah, got a halfway version in my clipboard. Tweaked slightly.

Comment on Re: stderr, local block and redirection Select or Download Code

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Re^2: stderr, local block and redirection by jfroebe (Parson) on Sep 13, 2006 at 17:07 UTC
Woohoo! that worked! :) Why would setting $output to a non undef value make it work? Jason L. Froebe Team Sybase member No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1	[reply]
Re^3: stderr, local block and redirection by Fletch (Bishop) on Sep 13, 2006 at 17:43 UTC
Although it's not explicitly explained that I can find, my guess would be that under the hood it needs an actual not-`undef` `SvPV*` into which the data is written. Otherwise it's going to be trying to append things to the single global undefined value `&PV_sv_undef` which is what throws the error.	[reply] [d/l] [select]
Re^4: stderr, local block and redirection by ikegami (Patriarch) on Sep 13, 2006 at 18:30 UTC
I think the buffer for `read` and for `sysread` must be similarly initialized. `my $read = read($fh, my $buf='', $MAX_READ);` [download]	[reply] [d/l] [select]
Re^4: stderr, local block and redirection by jfroebe (Parson) on Sep 13, 2006 at 18:21 UTC
That makes perfect sense :) Interesting that it only occurs after the first occurance of the code. Into the bowels of the Perl engine I dare not go without asbestos lined bloomers. ;-) Jason L. Froebe Team Sybase member No one has seen what you have seen, and until that happens, we're all going to think that you're nuts. - Jack O'Neil, Stargate SG-1	[reply]