I have a somewhat similar situation, and here is how I solved it. My problem was on Linux, but hopefully there is something to be gained from this solution.

I only included a snippet from my entire script (which does a few other things). I have not run this snippet by itself, but I did run it with perl -c to make sure the syntax was OK at least. I also had to sanitize a few values before posting it publicly, so I hope that I didn't make an error doing that either.

#!/usr/bin/perl -w

use strict;
use warnings;
use Data::Dumper;

# Mnemonic: "lh" = log file handle.
open my $lh, '>', '/tmp/this_script.log' or die "Opening debug log fai
+led: $!";

######################################################################
+########
#
# Kill any process still holding a file open in /usr/local/tomcat.
#
######################################################################
+########
my @pids = lsof_grep('/usr/local/tomcat');
print $lh scalar localtime;
print $lh "\n+++++ Contents of \@pids (lsof_grep) +++++\n";
print $lh Dumper(\@pids);

for my $pid (@pids) {
    # This is the first time a few of these processes are being told t
+o shut
    # down.  Thus, we need to send a signal that lets them close their
+ open
    # files, which is the entire point of this whole script.
    kill 'TERM', $pid;
}
# Give those processes up 1 second per process to quit.
sleep @pids;

# Run lsof again.  We'll send a stronger signal this time to any proce
+sses
# that still have Tomcat files open.
@pids = lsof_grep('/usr/local/tomcat');
print $lh scalar localtime;
print $lh "\n+++++ Contents of \@pids (lsof_grep, 2nd time) +++++\n";
print $lh Dumper(\@pids);

for my $pid (@pids) {
    kill 'KILL', $pid;
}

close $lh;

exit 0;

sub lsof_grep {
    my $re = shift;

    my @lsof_out = qx{/usr/sbin/lsof};

    my %openfiles;

    for my $line (@lsof_out) {

        if ($line =~ m{$re}) {
            my @fields = split /\s+/, $line;

            $openfiles{$fields[-1]} = $fields[1];
        }

    }

    # %openfiles will have the same PID multiple times.  Once for each
+ open
    # file it has.  However, we don't want the PID repeated in the ret
+urn
    # list.  We still need to print the contents of %openfiles for pot
+ential
    # debug purposes, however.
    print $lh scalar localtime;
    print $lh "\n+++++ Contents of \%openfile +++++\n";
    print $lh Dumper(\%openfiles);
    # %seen is only used in the next grep to make the expression work,
+ because
    # hash keys are unique.
    my %seen;
    return grep { !$seen{$_}++ } values %openfiles;
}
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