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.