#!/usr/bin/env perl
# (C) Pavel Polyakov bsd@kobyla.org 2020

our $has_sysctl=0;
                   use Carp 'croak';
                   use version;

                   sub require1 {
                       my ($filename) = @_;
                       if ( my $version = eval { version->parse($filename) } ) {
                           if ( $version > $^V ) {
                              my $vn = $version->normal;
                              croak "Perl $vn required--this is only $^V, stopped";
                           }
                           return 1;
                       }

                       if (exists $INC{$filename}) {
                           return 1 if $INC{$filename};
                           croak "Compilation failed in require";
                       }

                       foreach $prefix (@INC) {
                           if (ref($prefix)) {
                               #... do other stuff - see text below ....
                           }
                           # (see text below about possible appending of .pmc
                           # suffix to $filename)
                           my $realfilename = "$prefix/$filename";
                           next if ! -e $realfilename || -d _ || -b _;
                           $INC{$filename} = $realfilename;
                           my $result = do($realfilename);
                                        # but run in caller's namespace

                           if (!defined $result) {
                               $INC{$filename} = undef;
                               croak $@ ? "$@Compilation failed in require"
                                        : "Can't locate $filename: $!\n";
                           }
                           if (!$result) {
                               delete $INC{$filename};
                               croak "$filename did not return true value";
                           }
                           $! = 0;
                           return $result;
                       }
                       #print "Can't locate $filename in \@INC ...\n";
			return 0;
                   }

if(require1 'BSD/Sysctl.pm') {;
	#print "$!\n";
	BSD::Sysctl->import(qw/sysctl sysctl_description/);
	#print sysctl('kern.lastpid');
	$has_sysctl=1;
}


sub arg1(){
	my $a=shift @ARGV;
	return $a;
}


sub parse_sysctl {
	my $ref_str = shift;
	my $ref_hash = shift;

	my $name=undef;
	my $val=undef;
	for(split /[\r\n]+/s, $$ref_str) {
		if(/^([a-z][a-z0-9._%-]+):\s(.*)$/i) {	
			$name=$1;	
			$val=$2;
			#print "\t\t$name = $val\n";
			$$ref_hash{$name} = $val;
		}
		elsif(/^\s+(.*)$/i) {	
			$$ref_hash{$name} .= "\n\t$1";
		}
		else {
			$$ref_hash{$name} .= "\n\t$_";	# !!!
			#print STDERR "??? $name ??? $_\n";
		}
	}
}

sub get_sysctl {
	my $key=shift;
	my $val;
	if($has_sysctl) {
		$val=sysctl($key);
		#print "$key: $val\n";
		goto no_sct if ref $val || $val=~/\x00/;	
	} else {
	no_sct:
		$val=`$sysctl -n "$key"`;
	}
	chomp $val;
	return $val;
}

our $max_name=0;
our $max_val=0;
our $total=0;

sub print_sysctl {
	my $key=shift;
	my $desc=$desc{$key};
	my $val =$val{$key};

		my $is_multiline = $val=~/\n/s
				|| $print_desc && $desc=~/\n/s;

		if($print_table && !$is_multiline) {
			if($print_desc) {
				printf "%-${max_name}s : %${max_val}s : %s\n",
					$key, $val, $desc;
			} else {
				printf "%-${max_name}s : %${max_val}s\n",
					$key, $val;
			}
		} else {		
			if($print_desc) {
				print "$key : ", $val, " : ", $desc, "\n";
			} else {
				print "$key: ", $val, "\n";
			}
		}

		print "\n" if($print_multiline && $is_multiline);
		$total++;
}

our %val = ();
our %desc = ();
my $w_name=50;
my $w_val=50;
my $verbose=0;
my $only_single=0;
my $show_opaque=0;
my $search_desc=0;
my @search_tree=();

#my $cmd=undef;
my $help="Usage:
	$0 [options] [\@tree [\@tree]] <regexp> [options]
	List specified sysctl values (with description)
	\@tree	Start looking variables at the specified sysctl tree(s)
	-a	All sysctls (. pattern)
	-o	Include opaque values
	-1	Only single lined values
	-d	Include description in output
	-D	Search in description either
	-m	Separate multiline values with the blank line
	-s	Print stats
	-t	Table output
	BSD:Sysctl sysutils/p5-BSD-Sysctl can be installed for the better performance
";

while(defined ($_=arg1())) {
	if(/^-+(.*)/) {
		my $arg=$1;
		if($print_table     += $arg=~s/t//g) { }
		if($print_stats     += $arg=~s/s//g) { }
		if($print_multiline += $arg=~s/m//g) { }
		if($print_desc      += $arg=~s/d//g) { }
		if($search_desc     += $arg=~s/D//g) { }
		if($verbose         += $arg=~s/v//g) { }
		if($only_single     += $arg=~s/1//g) { }
		if($show_opaque     += $arg=~s/o//g) { }
		if($arg=~s/a//g) {
			$grep='.';
		}
		if($arg ne '') {
			#$cmd='help';
		help:
			print $help;
			exit 64;
		}
	}
	elsif(/^\@(.*)$/) {
		push @search_tree, $1;
	}
	else {
		$grep=$_;
	}
}

#print "grep: $grep\n";
no warnings 'deprecated';
goto help unless defined $grep;

print STDERR "has_bsd_sysctl = $has_sysctl\n" if $verbose;

our $sysctl=`\\which sysctl`;
chomp $sysctl;
if($sysctl eq '') {
	print STDERR "Error! Cant find sysctl utility\n";
	exit 69;
}


if ($show_opaque || $grep=~/hostcache\.list/) {
$desc{'net.inet.tcp.hostcache.list'} = 'List of all hostcache entries (opaque)';
};

#$sct = ` sysctl -a|egrep -v "^[|^<.>|^<...>"|egrep "$grep" `
#$sdt = ` sysctl -a|egrep "$grep" `
#$sct = `sysctl -a`;
$sdt = join(' ',@search_tree);
$sdt = `$sysctl -ad $sdt`;


parse_sysctl(\$sdt, \%desc);

if (!$show_opaque) {
delete $desc{'kern.msgbuf'};
};

#print "\n";
#print keys %desc;
#print "net.inet.tcp.rexmit_min = ",$desc{'net.inet.tcp.rexmit_min'}, "\n";



my @res_single=();
my @res_multi=();


my $key;
for $key (sort keys %desc) {
	if($key =~ /$grep/i 
	|| $search_desc && $desc{$key} =~ /$grep/ ) {
		my $val = get_sysctl($key);
		$val{$key}=$val;
		my $desc=$desc{$key};

		my $is_multiline = $val=~/\n/s
				|| $print_desc && $desc=~/\n/s;

		if($is_multiline) {
			if(!$only_single) {
			push @res_multi, $key;
			};
		} else {
			push @res_single, $key;
			$max_name = length($key) if(length($key) > $max_name);
			$max_val  = length($val) if(length($val) > $max_val);
		}

		#print_sysctl($key);
	}
}

for $key (@res_single) {
	print_sysctl($key);
}

print "\n" if scalar @res_multi && $print_multiline;
for $key (@res_multi) {
	print_sysctl($key);
}

if($print_stats) {
	print STDERR "Total $total variables listed\n";
}

# pkg install sysutils/p5-BSD-Sysctl