Re^2: How to find all open STDERR and STDOUT dups?

[tlm]

OK, I figured out why my original lsof experiment failed. I was using the recipe from the Perl Cookbook incorrectly. The following works as expected:

use warnings FATAL => 'all';
no warnings 'once';
use strict;

use Parse::RecDescent;

close_all_fds();
sub close_all_fds {
  my @lsof = `/usr/bin/lsof -p $$ 2>/dev/null`;
  for my $line ( @lsof ) {
    my @flds = split ' ', $line;
    next unless $flds[ 3 ] =~ /^(\d+)/;
    my $fd = $1;
    my $fh;
    print "closing $fd\n";
    closefd( $fd );
  }
  printf Parse::RecDescent::ERROR
    "Nya, nya!  I'm still open! (BTW, I'm fileno %d)\n",
      fileno( Parse::RecDescent::ERROR );
}

use Inline C => <<EOC;
#include <unistd.h>

void closefd( int fd ) {
  if ( close( fd ) )
    Perl_croak( aTHX_ "closefd( %d ) failed", fd );
  return;
}
EOC

__END__

I still need to figure out how to selectively close those handles that correspond to STDERR and STDOUT, but with the clues++ I got from almut, I think I should be able to do it.

[BrowserUk]

I still need to figure out how to selectively close those handles that correspond to STDERR and STDOUT,

Would it not be sufficient to simple close all open files in your child?

use POSIX ();

...
}
else { ## child
    POSIX::close( $_ ) for 0 .. 255; ## Or higher if that's a possibil
+ity
'''
}