#!/usr/local/bin/perl5
#
# count_pf.perl5 -- run lsof in repeat mode and count processes and
#		    files

sub interrupt { print "\n"; exit 0; }

$LSOF = "../lsof";			# path to lsof
$RPT = 15;				# lsof repeat time

if ( ! -x $LSOF) { print "can't execute $LSOF\n"; exit 1 }

# Read lsof -HPF0 output repeatedly from a pipe.

$| = 1;					# unbuffer output
$SIG{'INT'} = 'interrupt';		# catch interrupt
$proc = $files = $tcp = $udp = 0;
$progress="/";
open(P, "$LSOF -HPF0 -r $RPT|") || die "can't open pipe to $LSOF\n";

LSOF_LINE:

while (<P>) {
    chop;
    if (/^m/) {

    # A marker line signals the end of an lsof repetition.

	printf "%s  Processes: %5d,  Files: %6d,  TCP: %6d, UDP: %6d\r",
	    $progress, $proc, $files, $tcp, $udp;
	$proc = $files = $tcp = $udp = 0;
	if ($progress eq "/") { $progress = "\\"; } else { $progress = "/"; }
	next LSOF_LINE;
    }
    if (/^p/) {

    # Count process.

	$proc++;
	next LSOF_LINE;
    }
    if (/^f/) {

    # Count files.

	$files++;
	@F = split("\0", $_, 999);
	foreach $i (0 .. ($#F - 1)) {

	# Search for protocol field.

	    if ($F[$i] =~ /^P(.*)/) {

	    # Count instances of TCP and UDP protocols.

		if ($1 eq "TCP") { $tcp++; }
		elsif ($1 eq "UDP") { $udp++; }
		next LSOF_LINE;
	    }
	}
    }
}