in reply to Log message in Die handler

Because when you open a in handler it opens file and assigns to it descriptor with first available number -- 2 (STDERR).

Update: try this:

#!/usr/bin/perl 
use strict;
use warnings;

close STDERR;
open FH, '>', 'log';
die "exit from program\n";

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Update2: or more correct method:

#!/usr/bin/perl 
use strict;
use warnings;
use POSIX qw(dup2);

open FH, '>', 'log';
dup2(fileno FH, 2);
die "exit from program\n";

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But actually I prefer using Log::Log4perl and its logdie method.

Update3: uhm, I just discovered, that when you open STDERR perl always assigns it to descriptor 2:

#!/usr/bin/perl 
use strict;
use warnings;
use POSIX qw(dup2);

open FH, '>', 'log';
dup2(fileno FH, 2);
open STDERR, '>', 'stderr';
# this would be placed into 'stderr', not into 'log'
warn "STDERR descriptor is:", fileno(STDERR), "\n";
die "exit from program\n";

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Re^2: Log message in Die handler
by gone2015 (Deacon) on Jan 16, 2009 at 13:36 UTC

    Good grief. This seems to imply that if you close STDERR then die (and other diagnostics ?) will happily be written to whatever happens to be attached as descriptor 2 ?

    If so, then the trick appears to be to open STDERR '>', '/dev/nul', or something else to occupy descriptor 2 to squelch output ? Thinking about a more portable solution I tried:

      use strict ; use warnings ;

  sub die_handler {
    open FH, ">&1";
    print FH "die_handler: ", @_ ;
  } ;

  $SIG{__DIE__} = \&die_handler ;

  close STDERR ;
  open STDERR, '<', \'' ;

  die "Oh shoot !" ;

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    which appears to do the trick. Noting that the close STDERR is required.

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