From 4ee2f20bc6c8371e3039c4db6c22d89cd6c1dbed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 11:33:54 +0200
Subject: [PATCH 01/10] [perlcritic] fix lib/Munin/Plugin warnings

---
 Makefile                  |  2 +-
 lib/Munin/Plugin/Pgsql.pm | 10 ++++++----
 lib/Munin/Plugin/SNMP.pm  |  2 ++
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index f99b8627e5..6afe0cba65 100644
--- a/Makefile
+++ b/Makefile
@@ -58,7 +58,7 @@ install: $(BUILD_SCRIPT)
 .PHONY: perlcritic
 perlcritic:
 	#TODO: apply to scripts/ and lib/Munin/Master/
-	perlcritic lib/Munin/Node
+	perlcritic lib/Munin/Node lib/Munin/Plugin
 
 .PHONY: lint
 lint:
diff --git a/lib/Munin/Plugin/Pgsql.pm b/lib/Munin/Plugin/Pgsql.pm
index 8e6a220cf7..21fc57695b 100644
--- a/lib/Munin/Plugin/Pgsql.pm
+++ b/lib/Munin/Plugin/Pgsql.pm
@@ -105,6 +105,8 @@ package Munin::Plugin::Pgsql;
 use strict;
 use warnings;
 
+use English qw(-no_match_vars);
+
 use Munin::Plugin;
 
 =head2 Initialization
@@ -449,7 +451,7 @@ sub _connect() {
 
     return 1 if ($self->{dbh});
 
-    if (eval "require DBI; require DBD::Pg;") {
+    if (eval {require DBI; require DBD::Pg;}) {
 
         # By default, connect to database template1, because it exists on both old
         # and new versions of PostgreSQL, unless the database should be controlled
@@ -469,7 +471,7 @@ sub _connect() {
             $err_str =~ s/[\r\n\t]/ /g;
             $err_str =~ s/\h+/ /g;
             $err_str =~ s/ $//;
-            $self->{connecterror} = $err_str;	
+            $self->{connecterror} = $err_str;
             return 0;
         }
     }
@@ -595,14 +597,14 @@ sub replace_wildcard_parameters {
 sub wildcard_parameter {
     my ($self, $paramnum) = @_;
 
-    return undef unless (defined $self->{basename});
+    return unless (defined $self->{basename});
 
     $paramnum = 0 unless (defined $paramnum);
     if ($0 =~ /$self->{basename}(.*)$/) {
 
         # If asking for first parameter, and there's no filter on it,
         # return undef.
-        return undef if ($1 eq "ALL" && $paramnum == 0);
+        return if ($1 eq "ALL" && $paramnum == 0);
 
         # If asking for unsplit, return that (internal use only, really)
         return $1 if ($paramnum == -1);
diff --git a/lib/Munin/Plugin/SNMP.pm b/lib/Munin/Plugin/SNMP.pm
index 5ecb71048a..f18ec784d7 100644
--- a/lib/Munin/Plugin/SNMP.pm
+++ b/lib/Munin/Plugin/SNMP.pm
@@ -54,6 +54,8 @@ package Munin::Plugin::SNMP;
 use strict;
 use warnings;
 
+use English qw(-no_match_vars);
+
 use Net::SNMP;
 use Munin::Plugin;
 

From af988c985b24824e93cebdd7af90fea407f4010a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 12:23:13 +0200
Subject: [PATCH 02/10] [perlcritic] fix lib/Munin/Common warnings

---
 Makefile                         |  2 +-
 lib/Munin/Common/Logger.pm       |  4 ++-
 lib/Munin/Common/SyncDictFile.pm | 30 +++++++++++++----------
 lib/Munin/Common/TLS.pm          | 42 ++++++++++++++++----------------
 lib/Munin/Common/TLSClient.pm    |  4 +--
 lib/Munin/Common/TLSServer.pm    |  2 +-
 lib/Munin/Common/Timeout.pm      |  8 +++---
 7 files changed, 49 insertions(+), 43 deletions(-)

diff --git a/Makefile b/Makefile
index 6afe0cba65..4a39095910 100644
--- a/Makefile
+++ b/Makefile
@@ -58,7 +58,7 @@ install: $(BUILD_SCRIPT)
 .PHONY: perlcritic
 perlcritic:
 	#TODO: apply to scripts/ and lib/Munin/Master/
-	perlcritic lib/Munin/Node lib/Munin/Plugin
+	perlcritic lib/Munin/Node lib/Munin/Plugin lib/Munin/Common
 
 .PHONY: lint
 lint:
diff --git a/lib/Munin/Common/Logger.pm b/lib/Munin/Common/Logger.pm
index 2ff0ce5e0f..2bb2d5132b 100644
--- a/lib/Munin/Common/Logger.pm
+++ b/lib/Munin/Common/Logger.pm
@@ -20,6 +20,8 @@ our @EXPORT
 use Params::Validate qw(validate SCALAR);
 use POSIX;
 
+use English qw(-no_match_vars);
+
 sub _program_name {
     my @path = split( '/', $0 );
     return $path[-1];
@@ -47,7 +49,7 @@ my $screen_format = sub {
 
     chomp $message;
 
-    return sprintf( "%s [%s][%06d]: %s\n", _timestamp, $level, $$, $message );
+    return sprintf( "%s [%s][%06d]: %s\n", _timestamp, $level, $PID, $message );
 };
 
 my $file_format = $screen_format;
diff --git a/lib/Munin/Common/SyncDictFile.pm b/lib/Munin/Common/SyncDictFile.pm
index 5d2116687e..c6fb949eae 100644
--- a/lib/Munin/Common/SyncDictFile.pm
+++ b/lib/Munin/Common/SyncDictFile.pm
@@ -1,4 +1,8 @@
 package Munin::Common::SyncDictFile;
+
+use strict;
+use warnings;
+
 require Tie::Hash;
 our @ISA = qw(Tie::Hash);
 
@@ -28,7 +32,7 @@ sub STORE {
 	my ($self, $key, $value) = @_;
 	DEBUG("STORE($key, $value)");
 	$key = escape_key($key);
-	
+
 
 	use IO::File;
 	my $fh = _lock_write($self->{filename}, "r");
@@ -41,7 +45,7 @@ sub STORE {
 		# Print the read line, but ignore the key we are currently storing
 		print $fh_tmp "$line\n" unless $line =~ m/^$key:/;
 	}
-	
+
 	# Print the stored key at the end
 	DEBUG("Print the stored $key:$value");
 	print $fh_tmp "$key:$value\n";
@@ -73,7 +77,7 @@ sub FETCH {
 
 # Return the first key in the hash.
 sub FIRSTKEY {
-	my ($self) = @_; 
+	my ($self) = @_;
 	DEBUG("FIRSTKEY()");
 	my $fh = _lock_read($self->{filename});
 
@@ -88,11 +92,11 @@ sub FIRSTKEY {
 
 # Return the next key in the hash.
 sub NEXTKEY {
-	my ($self, $lastkey) = @_;
-	DEBUG("NEXTKEY($lastkey)");
+	my ($self, $key) = @_;
+	DEBUG("NEXTKEY($key)");
 	$key = escape_key($key);
 	my $fh = _lock_read($self->{filename});
-	
+
 	# Read the file to find a key
 	while(my $line = <$fh>) {
 		chomp($line);
@@ -105,7 +109,7 @@ sub NEXTKEY {
 			return $1;
 		} else {
 			# EOF
-			return undef;
+			return;
 		}
 	}
 }
@@ -139,16 +143,16 @@ sub DELETE {
 
 # Clear all values from the tied hash this.
 sub CLEAR {
-	my ($self) = @_; 
+	my ($self) = @_;
 	DEBUG("CLEAR()");
 	my $fh = $self->_lock_write();
 }
 
 sub SCALAR {
-	my ($self) = @_; 
+	my ($self) = @_;
 	DEBUG("SCALAR()");
 	my $fh = _lock_read($self->{filename});
-	
+
 	# Read the file to read the number of lines
 	my $nb_lines = 0;
 	while(my $line = <$fh>) {
@@ -177,15 +181,15 @@ sub _lock_write {
 
 	use Fcntl qw(:flock);
 	use IO::File;
-	
-	my $fh = IO::File->new($filename, $mode) 
+
+	my $fh = IO::File->new($filename, $mode)
 		or die "Cannot open tied file '$filename' - $!";
 	flock($fh, LOCK_EX) or die "Cannot lock tied file '$filename' - $!";
 	return $fh;
 }
 
 sub DEBUG {
-	print STDOUT "[DEBUG] @_" . "\n" if $DEBUG_ENABLED; 
+	print STDOUT "[DEBUG] @_" . "\n" if $DEBUG_ENABLED;
 }
 
 # XXX - collision if there is a ____
diff --git a/lib/Munin/Common/TLS.pm b/lib/Munin/Common/TLS.pm
index f0186abab8..54d8d7532a 100644
--- a/lib/Munin/Common/TLS.pm
+++ b/lib/Munin/Common/TLS.pm
@@ -53,15 +53,15 @@ sub _start_tls {
     my $self = shift;
 
     my %tls_verified = (
-        level          => 0, 
+        level          => 0,
         cert           => "",
-        verified       => 0, 
-        required_depth => $self->{tls_vdepth}, 
+        verified       => 0,
+        required_depth => $self->{tls_vdepth},
         verify         => $self->{tls_verify},
     );
 
     DEBUG("[TLS] Enabling TLS.") if $self->{DEBUG};
-    
+
     $self->_load_net_ssleay()
         or return 0;
 
@@ -71,16 +71,16 @@ sub _start_tls {
 
     $self->_load_private_key()
         or return 0;
-    
+
     $self->_load_certificate();
 
     $self->_load_ca_certificate();
-    
+
     $self->_initial_communication()
         or return 0;
-    
+
     $self->_set_peer_requirements(\%tls_verified);
-    
+
     if (! ($self->{tls_session} = Net::SSLeay::new($self->{tls_context})))
     {
 	ERROR("Could not create TLS: $!");
@@ -103,7 +103,7 @@ sub _load_net_ssleay {
     eval {
         require Net::SSLeay;
     };
-    if ($@) {
+    if ($EVAL_ERROR) {
 	ERROR("TLS enabled but Net::SSLeay unavailable.");
 	return 0;
     }
@@ -146,8 +146,8 @@ sub _load_private_key {
 
     if (defined $self->{tls_priv} and length $self->{tls_priv}) {
     	if (-e $self->{tls_priv} or $self->{tls_paranoia} eq "paranoid") {
-	    if (Net::SSLeay::CTX_use_PrivateKey_file($self->{tls_context}, 
-                                                     $self->{tls_priv}, 
+	    if (Net::SSLeay::CTX_use_PrivateKey_file($self->{tls_context},
+                                                     $self->{tls_priv},
                                                      &Net::SSLeay::FILETYPE_PEM)) {
                 $self->{private_key_loaded} = 1;
             }
@@ -211,7 +211,7 @@ sub _set_peer_requirements {
     if (defined $err and length $err) {
         WARNING("in set_verify_depth: $err");
     }
-    Net::SSLeay::CTX_set_verify ($self->{tls_context}, 
+    Net::SSLeay::CTX_set_verify ($self->{tls_context},
                                  $self->{tls_verify}  ? &Net::SSLeay::VERIFY_PEER :
                                                         &Net::SSLeay::VERIFY_NONE,
                                  $self->_tls_verify_callback($tls_verified));
@@ -219,7 +219,7 @@ sub _set_peer_requirements {
     if (defined $err and length $err) {
         WARNING("in set_verify: $err");
     }
-    
+
     return 1;
 }
 
@@ -228,7 +228,7 @@ sub _tls_verify_callback {
     my ($self, $tls_verified) = @_;
 
     return sub {
-        my ($ok, $subj_cert, $issuer_cert, $depth, 
+        my ($ok, $subj_cert, $issuer_cert, $depth,
 	    $errorcode, $arg, $chain) = @_;
 
         $tls_verified->{"level"}++;
@@ -238,7 +238,7 @@ sub _tls_verify_callback {
             DEBUG("[TLS] Verified certificate.") if $self->{DEBUG};
             return 1;           # accept
         }
-        
+
         if (!($tls_verified->{"verify"})) {
             DEBUG("[TLS] Certificate failed verification, but we aren't verifying.") if $self->{DEBUG};
             $tls_verified->{"verified"} = 1;
@@ -321,7 +321,7 @@ sub _accept_or_connect {
     }
     elsif ($self->{"tls_match"} and
     	Net::SSLeay::dump_peer_certificate($self->{tls_session}) !~ /$self->{tls_match}/)
-    { 
+    {
 	ERROR("Could not match pattern \"" . $self->{tls_match} .
 		"\" in dump of certificate.");
 	$self->_on_unmatched_cert();
@@ -342,7 +342,7 @@ sub _accept_or_connect {
 sub _initial_communication {
     my ($self) = @_;
     croak "Abstract method called '_initial_communication', "
-        . "needs to be defined in child" 
+        . "needs to be defined in child"
             if ref $self eq __PACKAGE__;
 }
 
@@ -351,7 +351,7 @@ sub _initial_communication {
 sub _use_key_if_present {
     my ($self) = @_;
     croak "Abstract method called '_use_key_if_present', "
-        . "needs to be defined in child" 
+        . "needs to be defined in child"
             if ref $self eq __PACKAGE__;
 }
 
@@ -365,7 +365,7 @@ sub _on_unmatched_cert {}
 sub read {
     my ($self) = @_;
 
-    croak "Tried to do an encrypted read, but a TLS session is not started" 
+    croak "Tried to do an encrypted read, but a TLS session is not started"
         unless $self->session_started();
 
     my $read = Net::SSLeay::read($self->{tls_session});
@@ -384,7 +384,7 @@ sub read {
 sub write {
     my ($self, $text) = @_;
 
-    croak "Tried to do an encrypted write, but a TLS session is not started" 
+    croak "Tried to do an encrypted write, but a TLS session is not started"
         unless $self->session_started();
 
     DEBUG("DEBUG: > $text") if $self->{DEBUG};
@@ -395,7 +395,7 @@ sub write {
         ERROR("[TLS] Warning in write: $err");
         return 0;
     }
-    
+
     return 1;
 }
 
diff --git a/lib/Munin/Common/TLSClient.pm b/lib/Munin/Common/TLSClient.pm
index fbf68e79bd..53b8d83506 100644
--- a/lib/Munin/Common/TLSClient.pm
+++ b/lib/Munin/Common/TLSClient.pm
@@ -11,7 +11,7 @@ use Munin::Common::Logger;
 
 sub new {
     my ($class, $args) = @_;
-    
+
     my $self = $class->SUPER::new($args);
 
     $self->{remote_key} = 0;
@@ -28,7 +28,7 @@ sub start_tls {
 
 sub _initial_communication {
     my ($self) = @_;
-    
+
     $self->{write_func}("STARTTLS\n");
     my $tlsresponse = $self->{read_func}();
     if (!defined $tlsresponse) {
diff --git a/lib/Munin/Common/TLSServer.pm b/lib/Munin/Common/TLSServer.pm
index f81c6ee9d1..daaeb411f5 100644
--- a/lib/Munin/Common/TLSServer.pm
+++ b/lib/Munin/Common/TLSServer.pm
@@ -31,7 +31,7 @@ sub _initial_communication {
     else {
         $self->{write_func}("TLS MAYBE\n");
     }
-            
+
     return 1;
 }
 
diff --git a/lib/Munin/Common/Timeout.pm b/lib/Munin/Common/Timeout.pm
index 3772e7cbdc..c1ce8534b7 100644
--- a/lib/Munin/Common/Timeout.pm
+++ b/lib/Munin/Common/Timeout.pm
@@ -26,9 +26,9 @@ my $current_timeout_epoch;
 sub do_with_timeout {
     my ($timeout, $block) = @_;
 
-    croak 'Argument exception: $timeout' 
+    croak 'Argument exception: $timeout'
         unless $timeout && $timeout =~ /^\d+$/;
-    croak 'Argument exception: $block' 
+    croak 'Argument exception: $block'
         unless ref $block eq 'CODE';
 
     my $new_timeout_epoch = time + $timeout;
@@ -41,7 +41,7 @@ sub do_with_timeout {
 
     if ($new_timeout_epoch <= time) {
     	# Yey ! Time's up already, don't do anything, just : "farewell !"
-        return undef;
+        return;
     }
 
     # Ok, going under new timeout setting
@@ -75,7 +75,7 @@ sub do_with_timeout {
 
     # And handle the return code
     if ($err) {
-        return undef if $err eq "alarm\n";
+        return if $err eq "alarm\n";
         die $err; # Propagate any other exceptions
     }
 

From 2273393cc5e6c602ea83717c3f83879a435fd1ce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 12:26:31 +0200
Subject: [PATCH 03/10] [perlcritic] fix lib/Munin/Master warnings

---
 Makefile                         |  4 ++--
 lib/Munin/Master/Config.pm       |  4 ++--
 lib/Munin/Master/Graph.pm        |  9 ++++++---
 lib/Munin/Master/HTML.pm         |  5 +++--
 lib/Munin/Master/Host.pm         |  2 +-
 lib/Munin/Master/LimitsOld.pm    | 16 ++++++++--------
 lib/Munin/Master/Node.pm         | 21 +++++++++++----------
 lib/Munin/Master/Update.pm       |  4 ++--
 lib/Munin/Master/UpdateWorker.pm | 15 ++++++++-------
 lib/Munin/Master/Utils.pm        |  8 ++++----
 10 files changed, 47 insertions(+), 41 deletions(-)

diff --git a/Makefile b/Makefile
index 4a39095910..c0efa45b0c 100644
--- a/Makefile
+++ b/Makefile
@@ -57,8 +57,8 @@ install: $(BUILD_SCRIPT)
 #TODO: merge with lint target, when done
 .PHONY: perlcritic
 perlcritic:
-	#TODO: apply to scripts/ and lib/Munin/Master/
-	perlcritic lib/Munin/Node lib/Munin/Plugin lib/Munin/Common
+	#TODO: apply to scripts/
+	perlcritic lib/
 
 .PHONY: lint
 lint:
diff --git a/lib/Munin/Master/Config.pm b/lib/Munin/Master/Config.pm
index 206cf9b3ea..240d407606 100644
--- a/lib/Munin/Master/Config.pm
+++ b/lib/Munin/Master/Config.pm
@@ -544,7 +544,7 @@ sub look_up {
 	    $value = $value->{groups}{$group};
 
 	} else {
-	    return undef;
+	    return;
 	}
     }
 
@@ -555,7 +555,7 @@ sub look_up {
 	return $value->{hosts}{$host};
     };
 
-    return undef;
+    return;
 }
 
 
diff --git a/lib/Munin/Master/Graph.pm b/lib/Munin/Master/Graph.pm
index 433783a1b5..5f9d9c7844 100644
--- a/lib/Munin/Master/Graph.pm
+++ b/lib/Munin/Master/Graph.pm
@@ -26,6 +26,8 @@ use warnings;
 
 package Munin::Master::Graph;
 
+use English qw(-no_match_vars);
+
 use Time::HiRes;
 
 use POSIX;
@@ -104,7 +106,7 @@ my %CONTENT_TYPES = (
 sub is_ext_handled
 {
 	my $ext = shift;
-	return undef unless $ext;
+	return unless $ext;
 	return defined $CONTENT_TYPES{uc($ext)};
 }
 
@@ -612,7 +614,7 @@ sub handle_request
 	{
 		my $buffer;
 		# No buffering wanted when sending the file
-		local $| = 1;
+		local $OUTPUT_AUTOFLUSH = 1;
 		while (sysread($rrd_fh, $buffer, 40 * 1024)) { print $buffer; }
 	}
 
@@ -682,7 +684,7 @@ sub RRDs_graph {
 
 	waitpid( $chld_pid, 0 );
 
-	my $child_exit_status = ($? >> 8);
+	my $child_exit_status = ($CHILD_ERROR >> 8);
 
 	return $child_exit_status;
 }
@@ -776,6 +778,7 @@ sub RRDs_graph_or_dump {
 		print $out_fh "        \"columns\": " . (scalar @$columns) . ",\n";
 		print $out_fh "        \"legend\": [\n";
 		my $index = 0;
+		## no critic ControlStructures::ProhibitMutatingListFunctions
 		my @json_columns = map { s/\\l$//; $_; } @{ $columns }; # Remove trailing "\l"
 		for my $column ( @json_columns ) {
 			print $out_fh "            \"$column\"";
diff --git a/lib/Munin/Master/HTML.pm b/lib/Munin/Master/HTML.pm
index d851d09e6e..9ad933d68d 100755
--- a/lib/Munin/Master/HTML.pm
+++ b/lib/Munin/Master/HTML.pm
@@ -689,8 +689,9 @@ sub _get_params_services_for_comparison {
 		my @nodes;
 		$sth_node->execute($service_name, $grp_id);
 		while (my ($node_name, $node_url, $srv_url, $srv_label) = $sth_node->fetchrow_array) {
-			my $_srv_url = "$srv_url.html" if defined $srv_url;
-			my $_img_url = "/$srv_url-$comparison.$graph_ext" if defined $srv_url;
+			my ($_srv_url, $_img_url);
+			$_srv_url = "$srv_url.html" if defined $srv_url;
+			$_img_url = "/$srv_url-$comparison.$graph_ext" if defined $srv_url;
 			push @nodes, {
 				R_PATH => '',
 				NODENAME => $node_name,
diff --git a/lib/Munin/Master/Host.pm b/lib/Munin/Master/Host.pm
index 2494903ba8..7268e8e237 100644
--- a/lib/Munin/Master/Host.pm
+++ b/lib/Munin/Master/Host.pm
@@ -20,7 +20,7 @@ sub new {
         port          => 4949,
         update        => 1,
         use_node_name => 0,
-        
+
         %$attributes,
     };
 
diff --git a/lib/Munin/Master/LimitsOld.pm b/lib/Munin/Master/LimitsOld.pm
index a5ffb10d68..26f3cb3bf6 100644
--- a/lib/Munin/Master/LimitsOld.pm
+++ b/lib/Munin/Master/LimitsOld.pm
@@ -241,8 +241,8 @@ Options:
 
 # Get the host of the service in question
 sub get_host_node {
-    my $service = shift || return undef;
-    my $parent  = munin_get_parent($service) || return undef;
+    my $service = shift || return;
+    my $parent  = munin_get_parent($service) || return;
 
     if (munin_has_subservices($parent)) {
 	return get_host_node($parent);
@@ -265,7 +265,7 @@ sub get_notify_name {
 
 # Joined "sub-path" under host level
 sub get_full_service_name {
-    my $service    = shift || return undef;
+    my $service    = shift || return;
     my $parent     = munin_get_parent($service);
     my $name       = get_notify_name($service);
 
@@ -279,7 +279,7 @@ sub get_full_service_name {
 
 # Joined group path above host level
 sub get_full_group_path {
-    my $group      = shift || return undef;
+    my $group      = shift || return;
     my $parent     = munin_get_parent($group);
     my $name       = get_notify_name($group);
 
@@ -467,7 +467,7 @@ sub process_service {
                             $hash->{'state_changed'} = 0;
                             $state = $onfield->{"state"};
                             $extinfo = $onfield->{$state};
-                            
+
                             # Start counting the number of consecutive UNKNOWN
                             # values seen.
                             $num_unknowns = 1;
@@ -649,9 +649,9 @@ sub generate_service_message {
     DEBUG "[DEBUG] generating service message: "
 	. join('::', @{munin_get_node_loc($hash)});
 
-    my $children = 
+    my $children =
 	munin_get_children(
-	    munin_get_node(\%notes, 
+	    munin_get_node(\%notes,
 			   munin_get_node_loc($hash)));
 
     if ( defined($children) ) {
@@ -783,7 +783,7 @@ sub generate_service_message {
                 # See https://github.com/munin-monitoring/munin/issues/382
                 # and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=291168.
                 close(STDOUT);
-                exec($cmd) or WARN "[WARNING] Failed to exec for contact $c in pid $$";
+                exec($cmd) or WARN "[WARNING] Failed to exec for contact $c in pid $PID";
                 exit;
             }
         }
diff --git a/lib/Munin/Master/Node.pm b/lib/Munin/Master/Node.pm
index 0d2fe9f313..c0256273b1 100644
--- a/lib/Munin/Master/Node.pm
+++ b/lib/Munin/Master/Node.pm
@@ -17,6 +17,7 @@ use Munin::Common::Logger;
 use Time::HiRes qw( gettimeofday tv_interval );
 use IO::Socket::INET6;
 
+use English qw(-no_match_vars);
 my $config = Munin::Master::Config->instance()->{config};
 
 # Quick version, to enable "DEBUG ... if $debug" constructs
@@ -85,7 +86,7 @@ sub _do_connect {
 		PeerAddr  => $uri->host,
 		PeerPort  => $self->{port} || 4949,
 		LocalAddr => $config->{local_address},
-		Proto     => 'tcp', 
+		Proto     => 'tcp',
 		MultiHomed => 1,
 		Timeout   => $config->{timeout}
 	);
@@ -175,7 +176,7 @@ sub _run_starttls_if_required {
         read_func    => sub { _node_read_single($self) },
         tls_ca_cert  => $config->{tls_ca_certificate},
         tls_cert     => $config->{tls_certificate},
-        tls_paranoia => $tls_requirement, 
+        tls_paranoia => $tls_requirement,
         tls_priv     => $config->{tls_private_key},
         tls_vdepth   => $config->{tls_verify_depth},
         tls_verify   => $config->{tls_verify_certificate},
@@ -370,7 +371,7 @@ sub parse_service_config {
 	    $correct++;
 	    # Special case for dirtyconfig
             my ($ds_name, $value, $when) = ($1, $2, $now);
-            
+
 	    $ds_name = $self->_sanitise_fieldname($ds_name);
 	    if ($value =~ /^(\d+):(.+)$/) {
 		$when = $1;
@@ -382,14 +383,14 @@ sub parse_service_config {
             $data_source_config->{$service}{$ds_name} ||= {};
             $data_source_config->{$service}{$ds_name}{when} ||= [];
             $data_source_config->{$service}{$ds_name}{value} ||= [];
-	
+
 	    # Saving the timed value in the datastructure
 	    push @{$data_source_config->{$service}{$ds_name}{when}}, $when;
 	    push @{$data_source_config->{$service}{$ds_name}{value}}, $value;
         }
 	elsif ($line =~ m{\A ([^\.]+)\.([^\s]+) \s+ (.+?) \s* $}xms) {
 	    $correct++;
-	    
+
             my ($ds_name, $ds_var, $ds_val) = ($1, $2, $3);
             $ds_name = $self->_sanitise_fieldname($ds_name);
             $data_source_config->{$service}{$ds_name} ||= {};
@@ -578,7 +579,7 @@ sub parse_service_data {
 	elsif ($line =~ m{\A ([^\.]+)\.extinfo \s+ (.+?) \s* $}xms) {
 	    # Extinfo is used in munin-limits
             my ($data_source, $value) = ($1, $2);
-	    
+
 	    $correct++;
 
             $data_source = $self->_sanitise_fieldname($data_source);
@@ -595,7 +596,7 @@ sub parse_service_data {
         }
     }
     if ($errors) {
-	my $percent = ($errors / ($errors + $correct)) * 100; 
+	my $percent = ($errors / ($errors + $correct)) * 100;
 	$percent = sprintf("%.2f", $percent);
 	WARN "[WARNING] $errors lines had errors while $correct lines were correct ($percent%) in data from 'fetch $plugin' on $nodedesignation";
     }
@@ -612,7 +613,7 @@ sub fetch_service_data {
     $self->_node_write_single("fetch $plugin\n");
 
     my $lines = $self->_node_read($uw_handle_data);
-    
+
     my $elapsed = tv_interval($t0);
     my $nodedesignation = $self->{host}."/".$self->{address}."/".$self->{port};
     INFO "data: $elapsed sec for '$plugin' on $nodedesignation";
@@ -638,7 +639,7 @@ sub _sanitise_plugin_name {
     my ($self, $name) = @_;
 
     $name =~ s/[^_A-Za-z0-9]/_/g;
-    
+
     return $name;
 }
 
@@ -714,7 +715,7 @@ sub _node_read_fast {
 	return _node_read(@_) if $self->{tls};
 
 	# Disable Buffering here, to be able to use sysread()
-	local $| = 1;
+	local $OUTPUT_AUTOFLUSH = 1;
 
 	my $io_src = $self->{reader};
         my $buf;
diff --git a/lib/Munin/Master/Update.pm b/lib/Munin/Master/Update.pm
index 688052a987..81820d54a7 100644
--- a/lib/Munin/Master/Update.pm
+++ b/lib/Munin/Master/Update.pm
@@ -131,7 +131,7 @@ sub _do_with_lock_and_timing {
     if (!open ($self->{STATS}, '>', "$config->{dbdir}/munin-update.stats.tmp")) {
         WARN "[WARNING] Could not open STATS to $config->{dbdir}/munin-update.stats.tmp: $!";
         # Use /dev/null instead - if the admin won't fix he won't care
-        open($self->{STATS}, '>', "/dev/null") or 
+        open($self->{STATS}, '>', "/dev/null") or
 	    LOGCROAK "[FATAL] Could not open STATS to /dev/null (fallback for not being able to open $config->{dbdir}/munin-update.stats.tmp): $!";
     }
 
@@ -221,7 +221,7 @@ sub _handle_worker_result {
 	LOGCROAK("[FATAL] Handle_worker_result got handed a failed worker result");
     }
 
-    my ($worker_id, $time_used, $service_configs) 
+    my ($worker_id, $time_used, $service_configs)
         = ($res->[0], $res->[1]{time_used}, $res->[1]{service_configs});
 
     my $update_time = sprintf("%.2f", $time_used);
diff --git a/lib/Munin/Master/UpdateWorker.pm b/lib/Munin/Master/UpdateWorker.pm
index 64b4e04025..5748735558 100644
--- a/lib/Munin/Master/UpdateWorker.pm
+++ b/lib/Munin/Master/UpdateWorker.pm
@@ -85,7 +85,7 @@ sub do_work {
 	# Having a local handle looks easier
 	my $node = $self->{node};
 
-    INFO "[INFO] starting work in $$ for $nodedesignation.\n";
+    INFO "[INFO] starting work in $PID for $nodedesignation.\n";
     my $done = $node->do_in_session(sub {
 
 	# A I/O timeout results in a violent exit.  Catch and handle.
@@ -221,7 +221,7 @@ FETCH_OK:
     }); # do_in_session
 
     # This handles failure in do_in_session,
-    return undef if ! $done || ! $done->{exit_value};
+    return if ! $done || ! $done->{exit_value};
 
     return {
         time_used => Time::HiRes::time - $update_time,
@@ -675,7 +675,8 @@ sub uw_handle_config {
 
 	# Delegate the FETCH part
 	my $update_rate = "300"; # XXX - should use the correct version
-	my $timestamp = $self->uw_handle_fetch($plugin, $now, $update_rate, \@fetch_data) if (@fetch_data);
+	my $timestamp;
+	$timestamp = $self->uw_handle_fetch($plugin, $now, $update_rate, \@fetch_data) if (@fetch_data);
 	$last_timestamp = $timestamp if $timestamp && $timestamp > $last_timestamp;
 
 	$self->{dbh}->commit() unless $self->{dbh}->{AutoCommit};
@@ -842,7 +843,7 @@ sub get_config_for_service {
 	}
 
 	# Not found
-	return undef;
+	return;
 }
 
 
@@ -1154,11 +1155,11 @@ sub convert_to_float
 sub dump_to_file
 {
 	my ($filename, $obj) = @_;
-	open(DUMPFILE, ">> $filename");
+	open(my $DUMPFILE, q{>>}, "$filename");
 
-	print DUMPFILE Dumper($obj);
+	print $DUMPFILE Dumper($obj);
 
-	close(DUMPFILE);
+	close($DUMPFILE);
 }
 
 sub _get_default_address
diff --git a/lib/Munin/Master/Utils.pm b/lib/Munin/Master/Utils.pm
index b48245ccc2..cff5eb2583 100644
--- a/lib/Munin/Master/Utils.pm
+++ b/lib/Munin/Master/Utils.pm
@@ -109,9 +109,9 @@ sub munin_getlock {
     my $pid = <LOCK>;
 
     if (defined($pid)) {
-	
+
 	DEBUG "[DEBUG] Lock contained pid '$pid'";
-	
+
         # Make sure it's a proper pid
 	if ($pid =~ /^(\d+)$/ and $1 != 1) {
 	    $pid = $1;
@@ -129,8 +129,8 @@ sub munin_getlock {
         seek(LOCK, 0, 0);
     }
     DEBUG "[DEBUG] Writing out PID to lock file $lockname";
-    print LOCK $$; # we want the pid inside for later use
-    if (defined($pid) && length $$ < length $pid) {
+    print LOCK $PID; # we want the pid inside for later use
+    if (defined($pid) && length $PID < length $pid) {
 	# Since pid was defined we need to truncate in case len($) < len($pid)
 	truncate(LOCK, tell(LOCK))
     }

From 1e5357d8fe673d82bf641349356198f2ec38559c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 12:18:08 +0200
Subject: [PATCH 04/10] [perlcritic] fix script/ warnings

---
 Makefile                    |  3 +--
 script/munin-async          | 13 +++++++------
 script/munin-asyncd         | 31 ++++++++++++++++---------------
 script/munin-httpd          |  8 ++++----
 script/munin-node           |  2 ++
 script/munin-node-configure |  7 +++++--
 script/munin-run            |  2 ++
 script/munin-update         |  3 ++-
 8 files changed, 39 insertions(+), 30 deletions(-)

diff --git a/Makefile b/Makefile
index c0efa45b0c..580230d124 100644
--- a/Makefile
+++ b/Makefile
@@ -57,8 +57,7 @@ install: $(BUILD_SCRIPT)
 #TODO: merge with lint target, when done
 .PHONY: perlcritic
 perlcritic:
-	#TODO: apply to scripts/
-	perlcritic lib/
+	perlcritic lib/ script/
 
 .PHONY: lint
 lint:
diff --git a/script/munin-async b/script/munin-async
index 4d20f461dc..e8f1ce8081 100755
--- a/script/munin-async
+++ b/script/munin-async
@@ -20,6 +20,7 @@
 use strict;
 use warnings;
 
+use English qw(-no_match_vars);
 use Sys::Hostname;
 use Data::Dumper;
 use Getopt::Long;
@@ -32,7 +33,7 @@ use Munin::Common::Logger;
 use Munin::Common::Utils qw( is_valid_hostname );
 
 # Disable buffering
-$| = 1;
+$OUTPUT_AUTOFLUSH = 1;
 
 my $SPOOLDIR = $Munin::Common::Defaults::MUNIN_SPOOLDIR;
 my $hostname;
@@ -141,14 +142,14 @@ sub cleanup {
 sub cat_file {
 	my $filename = shift;
 	return if ! -r $filename;
-	
-	open(FILE, "$filename");
-	while(<FILE>) { 
+
+	open(my $file, '<', "$filename");
+	while(<$file>) {
 		# remove line starting with .
 		next if m/^\./;
-		print $_; 
+		print $_;
 	}
-	close(FILE);
+	close($file);
 }
 
 __END__
diff --git a/script/munin-asyncd b/script/munin-asyncd
index 556447a45a..72201a9a57 100755
--- a/script/munin-asyncd
+++ b/script/munin-asyncd
@@ -20,6 +20,7 @@
 use strict;
 use warnings;
 
+use English qw(-no_match_vars);
 use IO::Socket;
 use IO::File;
 use File::Path qw(mkpath);
@@ -85,7 +86,7 @@ $minrate = $update_rate if ! defined $minrate;
 $verbose = 1 if $debug;
 
 unless (-d $SPOOLDIR) {
-	mkpath($SPOOLDIR, { verbose => $verbose, } ) 
+	mkpath($SPOOLDIR, { verbose => $verbose, } )
 		or LOGCROAK("Cannot create '$SPOOLDIR': $!");
 }
 
@@ -129,11 +130,11 @@ my $process_name = "main";
 
 my $plugins = {};
 {
-	INFO("[$$][$process_name] Reading config from $host");
-	my $sock = new IO::Socket::INET( 
-		PeerAddr	=> "$host", 
+	INFO("[$PID][$process_name] Reading config from $host");
+	my $sock = new IO::Socket::INET(
+		PeerAddr	=> "$host",
 		Proto	=> 'tcp'
-	) || die "Error creating socket: $!"; 
+	) || die "Error creating socket: $!";
 
 	local $0 = "munin-asyncd [$metahostname] [list]";
 	DEBUG("[sock][>] cap multigraph dirtyconfig");
@@ -206,7 +207,7 @@ MAIN: while($keepgoing) {
 				$when_next = $should_be_next;
 			}
 
-			DEBUG("[$$][$process_name] $plugin: should_have_been $should_have_been (" .
+			DEBUG("[$PID][$process_name] $plugin: should_have_been $should_have_been (" .
 				localtime($should_have_been) .
 				"), should_be_next: $should_be_next (" .
 				localtime($should_be_next) .
@@ -249,10 +250,10 @@ MAIN: while($keepgoing) {
 	if ($sock)
 	{
 		if ( $sock->connected ) {
-			print STDERR "[$$][$process_name][>] quit\n" if $verbose;
+			print STDERR "[$PID][$process_name][>] quit\n" if $verbose;
 			print $sock "quit\n" ;
 		}
-		print STDERR "[$$][$process_name] closing sock\n" if $verbose;
+		print STDERR "[$PID][$process_name] closing sock\n" if $verbose;
 		$sock = undef;
 	}
 
@@ -266,14 +267,14 @@ MAIN: while($keepgoing) {
 	my $sleep_sec = $when_next - time;
 
 	if ($sleep_sec > 0) {
-		INFO("[$$][$process_name] Sleeping $sleep_sec sec");
+		INFO("[$PID][$process_name] Sleeping $sleep_sec sec");
 		sleep $sleep_sec;
 	} else {
-		INFO("[$$][$process_name] Already late : should sleep $sleep_sec sec\n");
+		INFO("[$PID][$process_name] Already late : should sleep $sleep_sec sec\n");
 	}
 }
 
-print STDERR "[$$][$process_name] Exiting\n" if $verbose;
+print STDERR "[$PID][$process_name] Exiting\n" if $verbose;
 
 sub fetch_data
 {
@@ -283,9 +284,9 @@ sub fetch_data
 	my $sock = shift;
 
 
-		print STDERR "[$$][$process_name][>][$plugin] asking for config\n" if $verbose;
+		print STDERR "[$PID][$process_name][>][$plugin] asking for config\n" if $verbose;
 
-		print STDERR "[$$][$process_name][>][$plugin][sock] config $plugin\n" if $debug;
+		print STDERR "[$PID][$process_name][>][$plugin][sock] config $plugin\n" if $debug;
 		print $sock "config $plugin\n";
 
 		my $is_dirtyconfig;
@@ -294,7 +295,7 @@ sub fetch_data
 
 		while(my $line = <$sock>) {
 			chomp($line);
-			print STDERR "[$$][$process_name][<][$plugin][sock] $line\n" if $debug;
+			print STDERR "[$PID][$process_name][<][$plugin][sock] $line\n" if $debug;
 
 			if ($line =~ m/^\./) {
 				# Starting with . => end
@@ -321,7 +322,7 @@ sub fetch_data
 		# if dirty config, bypass the "fetch" part
 		goto WRITE_SPOOL if $is_dirtyconfig;
 
-		INFO("[$$][$process_name][>][$plugin] asking for data\n");
+		INFO("[$PID][$process_name][>][$plugin] asking for data\n");
                 DEBUG("[sock][>][$plugin] fetch $plugin\n");
 		print $sock "fetch $plugin\n";
 
diff --git a/script/munin-httpd b/script/munin-httpd
index bd96bfa34c..401d6b1588 100755
--- a/script/munin-httpd
+++ b/script/munin-httpd
@@ -24,14 +24,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 =cut
 
+use strict;
+use warnings;
+
 # Trust PERL5LIB from environment
 use lib map { /(.*)/ } split(/:/, ($ENV{PERL5LIB} || ''));
 
 package Munin::Master::Http;
 
-use strict;
-use warnings;
-
 use HTTP::Server::Simple::CGI::PreFork;
 use base qw(HTTP::Server::Simple::CGI::PreFork);
 
@@ -56,7 +56,7 @@ sub handle_request
 		Munin::Master::Graph::handle_request($cgi);
 	} else {
 		Munin::Master::HTML::handle_request($cgi);
-	}	
+	}
 }
 
 package main;
diff --git a/script/munin-node b/script/munin-node
index d96f84d588..81aab6e03f 100755
--- a/script/munin-node
+++ b/script/munin-node
@@ -37,6 +37,8 @@ use Munin::Node::OS;
 use Munin::Node::Service;
 use Munin::Node::Server;
 
+use English qw(-no_match_vars);
+
 my $servicedir = "$Munin::Common::Defaults::MUNIN_CONFDIR/plugins";
 my $sconfdir = "$Munin::Common::Defaults::MUNIN_CONFDIR/plugin-conf.d";
 my $conffile = "$Munin::Common::Defaults::MUNIN_CONFDIR/munin-node.conf";
diff --git a/script/munin-node-configure b/script/munin-node-configure
index 9666c897ae..c981564ad5 100755
--- a/script/munin-node-configure
+++ b/script/munin-node-configure
@@ -24,6 +24,8 @@ use Munin::Common::Defaults;
 use Munin::Node::Configure::PluginList;
 use Munin::Node::Configure::Debug;
 
+use English qw(-no_match_vars);
+
 use Munin::Node::Config;
 my $config = Munin::Node::Config->instance();
 
@@ -136,7 +138,8 @@ sub parse_args
     # comma-delimited form
     @snmp_hosts = map { split /,/ } @snmp_hosts;
 
-    my $snmp = init_snmp(
+    my $snmp;
+    $snmp = init_snmp(
         hosts        => \@snmp_hosts,
         version      => $snmpver,
         port         => $snmpport,
@@ -314,7 +317,7 @@ sub init_snmp
 {
     unless (eval { require Munin::Node::SNMPConfig; }) {
         die "# ERROR: Cannot perform SNMP probing as Munin::Node::SNMPConfig module is not available.\n",
-            $@;
+            $EVAL_ERROR;
     }
     return Munin::Node::SNMPConfig->new(@_);
 }
diff --git a/script/munin-run b/script/munin-run
index 3dc37f45fb..d3fc4dbcb2 100755
--- a/script/munin-run
+++ b/script/munin-run
@@ -35,6 +35,8 @@ use Munin::Node::Config;
 use Munin::Node::OS;
 use Munin::Node::Service;
 
+use English qw(-no_match_vars);
+
 my $services;
 my $servicedir;
 my $conffile = "$Munin::Common::Defaults::MUNIN_CONFDIR/munin-node.conf";
diff --git a/script/munin-update b/script/munin-update
index eedd93b4c9..f4b1613182 100755
--- a/script/munin-update
+++ b/script/munin-update
@@ -61,6 +61,7 @@ sub configure {
 	my @files = grep { ! /^\.|~$/ } readdir($DIR);
 	closedir($DIR);
 
+	## no critic ControlStructures::ProhibitMutatingListFunctions
 	@files = map { $_ = $dirname.'/'.$_; } (sort @files);
 
 	foreach my $f (@files) {
@@ -84,7 +85,7 @@ sub parse_args {
     );
 
     GetOptions (
-        \%args, 
+        \%args,
         "config|config_file=s",
         "debug",
         "verbose",

From 584db4ae956ff21572d0f89fdef990d727613c46 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 12:30:51 +0200
Subject: [PATCH 05/10] [perlcritic] fix warnings in generated file

---
 lib/Munin/Common/Defaults.pm.PL | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/Munin/Common/Defaults.pm.PL b/lib/Munin/Common/Defaults.pm.PL
index a79e8c9a39..c1101ba224 100644
--- a/lib/Munin/Common/Defaults.pm.PL
+++ b/lib/Munin/Common/Defaults.pm.PL
@@ -54,9 +54,9 @@ our \$MUNIN_SPOOLDIR   = '$MUNIN_SPOOLDIR';
 # our \$MUNIN_MANDIR     = '';
 our \$MUNIN_LOGDIR     = '$MUNIN_LOGDIR';
 our \$MUNIN_STATEDIR   = '$MUNIN_STATEDIR';
-our \$MUNIN_USER       = \$^O eq 'MSWin32' ? '' : getpwuid \$EUID;
-our \$MUNIN_GROUP      = \$^O eq 'MSWin32' ? '' : getgrgid \$EGID;
-our \$MUNIN_PLUGINUSER = \$^O eq 'MSWin32' ? '' : getpwuid \$EUID;
+our \$MUNIN_USER       = \$OSNAME eq 'MSWin32' ? '' : getpwuid \$EUID;
+our \$MUNIN_GROUP      = \$OSNAME eq 'MSWin32' ? '' : getgrgid \$EGID;
+our \$MUNIN_PLUGINUSER = \$OSNAME eq 'MSWin32' ? '' : getpwuid \$EUID;
 our \$MUNIN_VERSION    = '$MUNIN_VERSION';
 our \$MUNIN_PERL       = '/usr/bin/perl';
 # our \$MUNIN_PERLLIB    = '';

From 6dfc047b2c4b8bf1be554b917abd9a275f26e037 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 14:06:13 +0200
Subject: [PATCH 06/10] [perlcritic] fix some more warnings

---
 .perlcriticrc                    | 20 +++++++++++++
 lib/Munin/Common/TLS.pm          |  2 +-
 lib/Munin/Common/TLSClient.pm    |  2 +-
 lib/Munin/Common/TLSServer.pm    |  2 +-
 lib/Munin/Master/Graph.pm        | 28 ++----------------
 lib/Munin/Master/HTML.pm         |  2 +-
 lib/Munin/Master/LimitsOld.pm    |  5 ++--
 lib/Munin/Master/UpdateWorker.pm |  1 -
 lib/Munin/Master/Utils.pm        | 49 ++++++++++++++++----------------
 lib/Munin/Node/Config.pm         |  2 +-
 lib/Munin/Plugin.pm              | 20 +++++++------
 lib/Munin/Plugin/Pgsql.pm        |  2 +-
 script/munin-update              |  2 +-
 13 files changed, 67 insertions(+), 70 deletions(-)

diff --git a/.perlcriticrc b/.perlcriticrc
index 1294b4476b..b37f68e29f 100644
--- a/.perlcriticrc
+++ b/.perlcriticrc
@@ -24,3 +24,23 @@ perltidyrc = perltidyrc
 [CodeLayout::ProhibitTrailingWhitespace]
 severity = 5
 
+[CodeLayout::ProhibitQuotedWordLists]
+severity = 5
+
+[CodeLayout::RequireTrailingCommas]
+severity = 5
+
+[ControlStructures::ProhibitUnreachableCode]
+severity = 5
+
+[Documentation::RequirePackageMatchesPodName]
+severity = 5
+
+[Miscellanea::ProhibitUnrestrictedNoCritic]
+severity = 5
+
+[TestingAndDebugging::ProhibitNoWarnings]
+severity = 5
+
+[Variables::ProhibitUnusedVariables]
+severity = 5
diff --git a/lib/Munin/Common/TLS.pm b/lib/Munin/Common/TLS.pm
index 54d8d7532a..fa5a083ddd 100644
--- a/lib/Munin/Common/TLS.pm
+++ b/lib/Munin/Common/TLS.pm
@@ -413,7 +413,7 @@ __END__
 
 =head1 NAME
 
-Munin::Node::TLS - Abstract base class implementing the STARTTLS protocol
+Munin::Common::TLS - Abstract base class implementing the STARTTLS protocol
 
 
 =head1 SYNOPSIS
diff --git a/lib/Munin/Common/TLSClient.pm b/lib/Munin/Common/TLSClient.pm
index 53b8d83506..432b8e62ff 100644
--- a/lib/Munin/Common/TLSClient.pm
+++ b/lib/Munin/Common/TLSClient.pm
@@ -67,7 +67,7 @@ __END__
 
 =head1 NAME
 
-Munin::Node::TLSClient - Implements the client side of the STARTTLS protocol
+Munin::Common::TLSClient - Implements the client side of the STARTTLS protocol
 
 
 =head1 SYNOPSIS
diff --git a/lib/Munin/Common/TLSServer.pm b/lib/Munin/Common/TLSServer.pm
index daaeb411f5..0b508dcf22 100644
--- a/lib/Munin/Common/TLSServer.pm
+++ b/lib/Munin/Common/TLSServer.pm
@@ -50,7 +50,7 @@ __END__
 
 =head1 NAME
 
-Munin::Node::TLSServer - Implements the server side of the STARTTLS protocol
+Munin::Common::TLSServer - Implements the server side of the STARTTLS protocol
 
 
 =head1 SYNOPSIS
diff --git a/lib/Munin/Master/Graph.pm b/lib/Munin/Master/Graph.pm
index 5f9d9c7844..53ace56cba 100644
--- a/lib/Munin/Master/Graph.pm
+++ b/lib/Munin/Master/Graph.pm
@@ -45,7 +45,6 @@ my %PALETTE;
 my @COLOUR;
 
 {
-	no warnings;
 	# This is the old munin palette. Note that it lacks contrast.
 	$PALETTE{'old'} = [
 		qw(22ff22 0022ff ff0000 00aaaa ff00ff
@@ -87,7 +86,7 @@ my %resolutions = (
 	"day"   => "300",
 	"week"  => "1500",
 	"month" => "7200",
-	"year"  => "86400"
+	"year"  => "86400",
 );
 
 my %CONTENT_TYPES = (
@@ -273,8 +272,6 @@ sub handle_request
 	my @rrd_legend;
 	my @rrd_sum;
 
-	my %negatives;
-
 	push @rrd_gfx, "COMMENT:\\t";
 	push @rrd_gfx, "COMMENT:Cur\\t";
 	push @rrd_gfx, "COMMENT:Min\\t";
@@ -666,27 +663,6 @@ sub RRDs_graph {
 	# when called the second time.
 	#
 	return RRDs::graph(@_);
-
-	use IPC::Open3;
-	use IO::String;
-
-	# We just revert to spawning a full featured rrdtool cmd for now.
-	my $chld_out = new IO::String();
-	my $chld_in = new IO::String();
-	my $chld_err = new IO::String();
-
-	local $ENV{PATH} = $1 if $ENV{PATH} =~ /(.*)/;
-
-	my $chld_pid = open3($chld_out, $chld_in, $chld_err, "rrdtool", "graphv", @_);
-
-	DEBUG "[DEBUG] RRDs_graph(chld_out=".${$chld_out->string_ref}.")";
-	DEBUG "[DEBUG] RRDs_graph(chld_err=".${$chld_err->string_ref}.")";
-
-	waitpid( $chld_pid, 0 );
-
-	my $child_exit_status = ($CHILD_ERROR >> 8);
-
-	return $child_exit_status;
 }
 
 sub RRDs_graph_or_dump {
@@ -778,7 +754,7 @@ sub RRDs_graph_or_dump {
 		print $out_fh "        \"columns\": " . (scalar @$columns) . ",\n";
 		print $out_fh "        \"legend\": [\n";
 		my $index = 0;
-		## no critic ControlStructures::ProhibitMutatingListFunctions
+		## no critic qw(ControlStructures::ProhibitMutatingListFunctions)
 		my @json_columns = map { s/\\l$//; $_; } @{ $columns }; # Remove trailing "\l"
 		for my $column ( @json_columns ) {
 			print $out_fh "            \"$column\"";
diff --git a/lib/Munin/Master/HTML.pm b/lib/Munin/Master/HTML.pm
index 9ad933d68d..e5b15ea581 100755
--- a/lib/Munin/Master/HTML.pm
+++ b/lib/Munin/Master/HTML.pm
@@ -115,7 +115,7 @@ sub handle_request
 		MUNIN_VERSION   => $Munin::Common::Defaults::MUNIN_VERSION,
 		TIMESTAMP       => strftime("%Y-%m-%d %T%z (%Z)", localtime),
 		R_PATH          => '',
-		GRAPH_EXT       => $graph_ext
+		GRAPH_EXT       => $graph_ext,
 	);
 
 
diff --git a/lib/Munin/Master/LimitsOld.pm b/lib/Munin/Master/LimitsOld.pm
index 26f3cb3bf6..1969983a9a 100644
--- a/lib/Munin/Master/LimitsOld.pm
+++ b/lib/Munin/Master/LimitsOld.pm
@@ -71,7 +71,7 @@ my %default_text = (
     "nagios" =>
         '${var:host}\t${var:graph_title}\t${var:worstid}\t${strtrunc:350 ${if:cfields CRITICALs:${loop<,>:cfields  ${var:label} is ${var:value} (outside range [${var:crange}])${if:extinfo : ${var:extinfo}}}.}${if:wfields WARNINGs:${loop<,>:wfields  ${var:label} is ${var:value} (outside range [${var:wrange}])${if:extinfo : ${var:extinfo}}}.}${if:ufields UNKNOWNs:${loop<,>:ufields  ${var:label} is ${var:value}${if:extinfo : ${var:extinfo}}}.}${if:fofields OKs:${loop<,>:fofields  ${var:label} is ${var:value}${if:extinfo : ${var:extinfo}}}.}}',
     "old-nagios" =>
-        '${var:host}\t${var:plugin}\t${var:worstid}\t${strtrunc:350 ${var:graph_title}:${if:cfields CRITICALs:${loop<,>:cfields  ${var:label} is ${var:value} (outside range [${var:crange}])${if:extinfo : ${var:extinfo}}}.}${if:wfields WARNINGs:${loop<,>:wfields  ${var:label} is ${var:value} (outside range [${var:wrange}])${if:extinfo : ${var:extinfo}}}.}${if:ufields UNKNOWNs:${loop<,>:ufields  ${var:label} is ${var:value}${if:extinfo : ${var:extinfo}}}.}${if:fofields OKs:${loop<,>:fofields  ${var:label} is ${var:value}${if:extinfo : ${var:extinfo}}}.}}'
+        '${var:host}\t${var:plugin}\t${var:worstid}\t${strtrunc:350 ${var:graph_title}:${if:cfields CRITICALs:${loop<,>:cfields  ${var:label} is ${var:value} (outside range [${var:crange}])${if:extinfo : ${var:extinfo}}}.}${if:wfields WARNINGs:${loop<,>:wfields  ${var:label} is ${var:value} (outside range [${var:wrange}])${if:extinfo : ${var:extinfo}}}.}${if:ufields UNKNOWNs:${loop<,>:ufields  ${var:label} is ${var:value}${if:extinfo : ${var:extinfo}}}.}${if:fofields OKs:${loop<,>:fofields  ${var:label} is ${var:value}${if:extinfo : ${var:extinfo}}}.}}',
 );
 
 sub limits_startup {
@@ -642,7 +642,8 @@ sub generate_service_message {
         'warning'  => [],
         'unknown'  => [],
         'foks'     => [],
-        'ok'       => []);
+        'ok'       => [],
+    );
 
     my $contacts = munin_get_children(munin_get_node($config, ["contact"]));
 
diff --git a/lib/Munin/Master/UpdateWorker.pm b/lib/Munin/Master/UpdateWorker.pm
index 5748735558..b3d9a57dfd 100644
--- a/lib/Munin/Master/UpdateWorker.pm
+++ b/lib/Munin/Master/UpdateWorker.pm
@@ -500,7 +500,6 @@ sub _db_state_update {
 	$sth_state->finish();
 
 	{
-		no warnings;
 		DEBUG "_db_state_update.last_epoch:$last_epoch";
 		DEBUG "_db_state_update.last_value:$last_value";
 	}
diff --git a/lib/Munin/Master/Utils.pm b/lib/Munin/Master/Utils.pm
index cff5eb2583..4712fe5bc1 100644
--- a/lib/Munin/Master/Utils.pm
+++ b/lib/Munin/Master/Utils.pm
@@ -25,24 +25,24 @@ use Scalar::Util qw(isweak weaken);
 our (@ISA, @EXPORT);
 
 @ISA = ('Exporter');
-@EXPORT = (
-	   'munin_removelock',
-	   'munin_runlock',
-	   'munin_getlock',
-	   'munin_get_bool',
-	   'munin_get',
-	   'munin_get_rrd_filename',
-	   'munin_get_node_name',
-	   'munin_get_node_loc',
-	   'munin_get_node',
-	   'munin_set_var_loc',
-	   'munin_set',
-	   'munin_mkdir_p',
-	   'munin_find_field_for_limits',
-	   'munin_get_children',
-	   'munin_has_subservices',
-	   'print_version_and_exit',
-	   'exit_if_run_by_super_user',
+@EXPORT = qw(
+	   munin_removelock
+	   munin_runlock
+	   munin_getlock
+	   munin_get_bool
+	   munin_get
+	   munin_get_rrd_filename
+	   munin_get_node_name
+	   munin_get_node_loc
+	   munin_get_node
+	   munin_set_var_loc
+	   munin_set
+	   munin_mkdir_p
+	   munin_find_field_for_limits
+	   munin_get_children
+	   munin_has_subservices
+	   print_version_and_exit
+	   exit_if_run_by_super_user
 	   );
 
 my $VERSION = $Munin::Common::Defaults::MUNIN_VERSION;
@@ -99,7 +99,6 @@ sub munin_runlock {
 
 sub munin_getlock {
     my ($lockname) = @_;
-    my $LOCK;
 
     if (sysopen (LOCK, $lockname, O_RDWR | O_CREAT)) {
 	DEBUG "[DEBUG] Create/open lock : $lockname succeeded\n";
@@ -242,7 +241,7 @@ Returns:
 
 Get all child hash nodes.
 
-Parameters: 
+Parameters:
  - $hash: A hash ref to the parent node
 
 Returns:
@@ -266,7 +265,7 @@ Returns:
 
 Get location array for hash node.
 
-Parameters: 
+Parameters:
  - $hash: A ref to the node
 
 Returns:
@@ -278,7 +277,7 @@ Returns:
 
 Return the name of the hash node supplied.
 
-Parameters: 
+Parameters:
  - $hash: A ref to the hash node
 
 Returns:
@@ -351,7 +350,7 @@ to it.
 
 Returns a loc array from a path string.
 
-Parameters: 
+Parameters:
  - $path: A path string
 
 Returns:
@@ -371,7 +370,7 @@ Returns:
 
 Sets a variable in a hash.
 
-Parameters: 
+Parameters:
  - $hash: A ref to the hash to set the variable in
  - $var: The name of the variable
  - $val: The value to set the variable to
@@ -385,7 +384,7 @@ Returns:
 
 Sets a variable in a hash.
 
-Parameters: 
+Parameters:
  - $hash: A ref to the hash to set the variable in
  - $loc: A ref to an array with the full path of the variable
  - $val: The value to set the variable to
diff --git a/lib/Munin/Node/Config.pm b/lib/Munin/Node/Config.pm
index 90eea326c8..ea203bffbc 100644
--- a/lib/Munin/Node/Config.pm
+++ b/lib/Munin/Node/Config.pm
@@ -268,7 +268,7 @@ sub _parse_plugin_line {
     elsif ($var_name eq 'command') {
     	# Don't split on escaped whitespace. Also support escaping the escape character.
     	# Better implementations welcome :).
-	## no critic ControlStructures::ProhibitMutatingListFunctions
+	## no critic qw(ControlStructures::ProhibitMutatingListFunctions)
         return (command => [reverse map {s/\\(.)/$1/g; scalar reverse} split /\s+(?=(?:\\\\)*(?!\\))/, reverse $var_value]);
     }
     elsif ($var_name eq 'host_name') {
diff --git a/lib/Munin/Plugin.pm b/lib/Munin/Plugin.pm
index 06bb1bd10c..7cc5d2fbff 100644
--- a/lib/Munin/Plugin.pm
+++ b/lib/Munin/Plugin.pm
@@ -28,7 +28,7 @@ use File::Temp; # File::Temp was first released with perl 5.006001
 # This file uses subroutine prototypes. This is considered a bad
 # practice according to PBP (see page 194).
 
-## no critic Prototypes
+## no critic qw(Prototypes)
 
 =head1 NAME 
 
@@ -56,6 +56,7 @@ set_state_name, save_state, restore_state, tail_open, tail_close.
 
 =cut
 
+use English qw(-no_match_vars);
 use Exporter;
 our @ISA = ('Exporter');
 our @EXPORT = qw(
@@ -303,7 +304,7 @@ sub restore_state {
 	my @state;
 	# Protects _restore_state_raw() with an eval()
 	eval { @state = _restore_state_raw(); };
-	if ($@) { @state = (); warn $@; }
+	if ($EVAL_ERROR) { @state = (); warn $EVAL_ERROR; }
 
 	return _decode_state(@state);
 }
@@ -317,7 +318,7 @@ sub _restore_state_raw {
     }
 
     # Read a state vector from a plugin appropriate state file
-    local $/;
+    local $INPUT_RECORD_SEPARATOR;
 
     my @state = split(/\n/, <$STATE>);
     my $filemagic = shift(@state);
@@ -395,7 +396,7 @@ these percentages against $base.
 sub adjust_threshold {
     my ($threshold, $base) = @_;
 
-    return undef if(!defined $threshold or !defined $base);
+    return if(!defined $threshold or !defined $base);
 
     $threshold =~ s!(\d+\.?\d*)%!$1*$base/100!eg;
 
@@ -462,8 +463,8 @@ the kernel exposes.
 sub readfile($) {
   my ($path) = @_;
 
-  open my $FH, "<", $path or return undef;
-  local $/;
+  open my $FH, "<", $path or return;
+  local $INPUT_RECORD_SEPARATOR;
   my $content = <$FH>;
   close $FH;
 
@@ -485,7 +486,7 @@ Returns an empty array if the file is empty (or contains only whitespace).
 sub readarray($) {
   my ($path) = @_;
 
-  open my $FH, "<", $path or return undef;
+  open my $FH, "<", $path or return;
   my $line = <$FH>;
   # handle an empty file gracefully
   $line = "" if not defined($line);
@@ -556,7 +557,7 @@ sub scaleNumber {
 		 1E+9,  'G',  # giga
 		 1E+6,  'M',  # mega
 		 1E+3,  'k',  # kilo
-		 1,     '');  # nothing
+		 1,     '',); # nothing
 
     my %small = (1,     '',   # nothing
 		 1E-3,  'm',  # milli
@@ -566,7 +567,7 @@ sub scaleNumber {
 		 1E-15, 'f',  # femto
 		 1E-18, 'a',  # atto
 		 1E-21, 'z',  # zepto
-		 1E-24, 'y'); # yocto
+		 1E-24, 'y',);# yocto
 
     # Get the absolute and exaggerate it slightly since floating point
     # numbers don't compare very well.
@@ -612,6 +613,7 @@ if it doesn't support multigraph plugins.
 sub need_multigraph {
     return if $ENV{MUNIN_CAP_MULTIGRAPH};
 
+    ## no critic qw(InputOutput::ProhibitInteractiveTest)
     if (-t and (!$ARGV[0] or ($ARGV[0] eq 'config'))) {
 
 	# Catch people running the plugin on the command line.  Note
diff --git a/lib/Munin/Plugin/Pgsql.pm b/lib/Munin/Plugin/Pgsql.pm
index 21fc57695b..0eb62cfb27 100644
--- a/lib/Munin/Plugin/Pgsql.pm
+++ b/lib/Munin/Plugin/Pgsql.pm
@@ -223,7 +223,7 @@ sub new {
         base      => 1000,
         category  => 'PostgreSQL',
         graphdraw => 'LINE1',
-        graphtype => 'GAUGE'
+        graphtype => 'GAUGE',
     );
 
     my $self = {
diff --git a/script/munin-update b/script/munin-update
index f4b1613182..d8c1fe8a0e 100755
--- a/script/munin-update
+++ b/script/munin-update
@@ -61,7 +61,7 @@ sub configure {
 	my @files = grep { ! /^\.|~$/ } readdir($DIR);
 	closedir($DIR);
 
-	## no critic ControlStructures::ProhibitMutatingListFunctions
+	## no critic qw(ControlStructures::ProhibitMutatingListFunctions)
 	@files = map { $_ = $dirname.'/'.$_; } (sort @files);
 
 	foreach my $f (@files) {

From 5a1b8ba04b66d39174d64a4c2e6853c7cb047a4d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 14:21:16 +0200
Subject: [PATCH 07/10] [perlcritic] merge make target with lint

---
 Makefile | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index 580230d124..9047fa7f8d 100644
--- a/Makefile
+++ b/Makefile
@@ -54,13 +54,11 @@ install: $(BUILD_SCRIPT)
 		-e "$$(perl -I lib -M"Munin::Common::Defaults" \
 			-e "Munin::Common::Defaults->print_as_sed_substitutions();")"
 
-#TODO: merge with lint target, when done
-.PHONY: perlcritic
-perlcritic:
-	perlcritic lib/ script/
-
 .PHONY: lint
 lint:
+	# Scanning munin code
+	perlcritic lib/ script/
+
 	@# SC1008: ignore our weird shebang (substituted later)
 	@# SC1090: ignore sourcing of files with variable in path
 	@# SC2009: do not complain about "ps ... | grep" calls (may be platform specific)

From 8d882187bdc01c434d7f5060e82f7f335c1368b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 21:11:47 +0200
Subject: [PATCH 08/10] [perlcritic] allow usage of $0

---
 .perlcriticrc            | 2 +-
 lib/Munin/Node/Server.pm | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.perlcriticrc b/.perlcriticrc
index b37f68e29f..479b3d3632 100644
--- a/.perlcriticrc
+++ b/.perlcriticrc
@@ -16,7 +16,7 @@ profile-strictness = quiet
 
 [Variables::ProhibitPunctuationVars]
 severity = 5
-allow = $_ $!
+allow = $_ $! $0
 
 [CodeLayout::RequireTidyCode]
 perltidyrc = perltidyrc
diff --git a/lib/Munin/Node/Server.pm b/lib/Munin/Node/Server.pm
index ca8b8b15de..053249f28a 100644
--- a/lib/Munin/Node/Server.pm
+++ b/lib/Munin/Node/Server.pm
@@ -120,7 +120,7 @@ sub process_request
     $session->{tls_mode}     = $config->{tls} || 'auto';
     $session->{peer_address} = $self->{server}->{peeraddr};
 
-    $PROGRAM_NAME .= " [$session->{peer_address}]";
+    $0 .= " [$session->{peer_address}]";
 
     # Used to provide per-master state-files
     $ENV{MUNIN_MASTER_IP} = $session->{peer_address};
@@ -216,7 +216,7 @@ sub _process_command_line {
 sub _get_commandline {
   my $self = shift;
 
-  my $script = $PROGRAM_NAME;
+  my $script = $0;
   # make relative path absolute
   $script = $ENV{'PWD'} .'/'. $script if $script =~ m|^[^/]+/| && $ENV{'PWD'};
   # untaint for later use in hup

From 39b4ecb4d450de5356986eff419b591f549c3d7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 21:18:43 +0200
Subject: [PATCH 09/10] [perlcritic] allow usage of $@

---
 .perlcriticrc                    | 2 +-
 HACKING.pod                      | 2 +-
 lib/Munin/Common/Config.pm       | 4 ++--
 lib/Munin/Common/TLS.pm          | 2 +-
 lib/Munin/Common/Timeout.pm      | 2 +-
 lib/Munin/Master/Config.pm       | 4 ++--
 lib/Munin/Master/Update.pm       | 4 ++--
 lib/Munin/Master/UpdateWorker.pm | 6 +++---
 lib/Munin/Master/Utils.pm        | 2 +-
 lib/Munin/Node/Config.pm         | 4 ++--
 lib/Munin/Node/Server.pm         | 6 +++---
 lib/Munin/Node/Service.pm        | 4 ++--
 lib/Munin/Plugin.pm              | 2 +-
 script/munin-node-configure      | 2 +-
 14 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/.perlcriticrc b/.perlcriticrc
index 479b3d3632..969e74e975 100644
--- a/.perlcriticrc
+++ b/.perlcriticrc
@@ -16,7 +16,7 @@ profile-strictness = quiet
 
 [Variables::ProhibitPunctuationVars]
 severity = 5
-allow = $_ $! $0
+allow = $_ $! $0 $@
 
 [CodeLayout::RequireTidyCode]
 perltidyrc = perltidyrc
diff --git a/HACKING.pod b/HACKING.pod
index e4abd805fb..db07673e50 100644
--- a/HACKING.pod
+++ b/HACKING.pod
@@ -145,7 +145,7 @@ Exceptions are caught with an eval:
  eval {
      # Exceptionally scary code
  };
- if ($EVAL_ERROR) {
+ if ($@) {
      # Handle exception
  }
 
diff --git a/lib/Munin/Common/Config.pm b/lib/Munin/Common/Config.pm
index 119bc30a2a..65e0118072 100644
--- a/lib/Munin/Common/Config.pm
+++ b/lib/Munin/Common/Config.pm
@@ -177,8 +177,8 @@ sub parse_config_from_file {
     eval {
         $self->parse_config($file);
     };
-    if ($EVAL_ERROR) {
-        croak "ERROR: Failed to parse config file '$config_file': $EVAL_ERROR";
+    if ($@) {
+        croak "ERROR: Failed to parse config file '$config_file': $@";
     }
 
     close $file
diff --git a/lib/Munin/Common/TLS.pm b/lib/Munin/Common/TLS.pm
index fa5a083ddd..e9c35a71ee 100644
--- a/lib/Munin/Common/TLS.pm
+++ b/lib/Munin/Common/TLS.pm
@@ -103,7 +103,7 @@ sub _load_net_ssleay {
     eval {
         require Net::SSLeay;
     };
-    if ($EVAL_ERROR) {
+    if ($@) {
 	ERROR("TLS enabled but Net::SSLeay unavailable.");
 	return 0;
     }
diff --git a/lib/Munin/Common/Timeout.pm b/lib/Munin/Common/Timeout.pm
index c1ce8534b7..6b0074a507 100644
--- a/lib/Munin/Common/Timeout.pm
+++ b/lib/Munin/Common/Timeout.pm
@@ -54,7 +54,7 @@ sub do_with_timeout {
         alarm ($new_timeout_epoch - time);
         $ret_value = $block->();
     };
-    my $err = $EVAL_ERROR;
+    my $err = $@;
 
     # Restore the old $current_timeout_epoch...
     $current_timeout_epoch = $old_current_timeout_epoch;
diff --git a/lib/Munin/Master/Config.pm b/lib/Munin/Master/Config.pm
index 240d407606..d0980dbb2e 100644
--- a/lib/Munin/Master/Config.pm
+++ b/lib/Munin/Master/Config.pm
@@ -377,9 +377,9 @@ sub _concat_config_line_ok {
     eval {
 	$self->_split_config_line_ok($longkey);
     };
-    if ($EVAL_ERROR) {
+    if ($@) {
 	# _split_config_line_ok already logged the problem.
-	my $err_msg = "[ERROR] config error under [$prefix] for '$key $value' : $EVAL_ERROR";
+	my $err_msg = "[ERROR] config error under [$prefix] for '$key $value' : $@";
 	ERROR $err_msg;
 	die $err_msg;
     }
diff --git a/lib/Munin/Master/Update.pm b/lib/Munin/Master/Update.pm
index 81820d54a7..939952825b 100644
--- a/lib/Munin/Master/Update.pm
+++ b/lib/Munin/Master/Update.pm
@@ -193,11 +193,11 @@ sub _run_workers {
 		$worker->{dbh_state}->disconnect();
 
 		my $worker_id = $worker->{ID};
-		if (! defined($res) || $EVAL_ERROR) {
+		if (! defined($res) || $@) {
 			# No res, something went wrong
 			# Note that we handle connection failure same as other
 			# failures. Since "do_connect()" fails only softly.
-			INFO "[INFO]: no connection or EVAL_ERROR:$EVAL_ERROR";
+			INFO "[INFO]: no connection or EVAL_ERROR:$@";
 			$pm->finish(1, [ $worker_id ] );
 		}
 
diff --git a/lib/Munin/Master/UpdateWorker.pm b/lib/Munin/Master/UpdateWorker.pm
index b3d9a57dfd..18627323e9 100644
--- a/lib/Munin/Master/UpdateWorker.pm
+++ b/lib/Munin/Master/UpdateWorker.pm
@@ -204,12 +204,12 @@ NODE_END:
 		kill 'KILL', $node_pid; # Using SIGKILL, since normal termination didn't happen
 	}
 
-	if ($EVAL_ERROR =~ m/^NO_SPOOLFETCH_DATA /) {
+	if ($@ =~ m/^NO_SPOOLFETCH_DATA /) {
 	    INFO "[INFO] No spoofetch data for $nodedesignation";
 	    return;
-	} elsif ($EVAL_ERROR) {
+	} elsif ($@) {
 	    ERROR "[ERROR] Error in node communication with $nodedesignation: "
-		.$EVAL_ERROR;
+		.$@;
 	    return;
 	}
 
diff --git a/lib/Munin/Master/Utils.pm b/lib/Munin/Master/Utils.pm
index 4712fe5bc1..368b8c0b91 100644
--- a/lib/Munin/Master/Utils.pm
+++ b/lib/Munin/Master/Utils.pm
@@ -143,7 +143,7 @@ sub munin_mkdir_p {
     eval {
         mkpath($dirname, 0, $umask);
     };
-    return if $EVAL_ERROR;
+    return if $@;
     return 1;
 }
 
diff --git a/lib/Munin/Node/Config.pm b/lib/Munin/Node/Config.pm
index ea203bffbc..717df639d6 100644
--- a/lib/Munin/Node/Config.pm
+++ b/lib/Munin/Node/Config.pm
@@ -198,10 +198,10 @@ sub parse_plugin_config_file {
 	if $self->{DEBUG};
 
     eval { $self->parse_plugin_config($CONF) };
-    if ($EVAL_ERROR) {
+    if ($@) {
         carp sprintf(
             '%s at %s line %d. Skipping the rest of the file',
-            $EVAL_ERROR,
+            $@,
             $file,
             $INPUT_LINE_NUMBER,
         );
diff --git a/lib/Munin/Node/Server.pm b/lib/Munin/Node/Server.pm
index 053249f28a..74c0812c9d 100644
--- a/lib/Munin/Node/Server.pm
+++ b/lib/Munin/Node/Server.pm
@@ -145,7 +145,7 @@ sub process_request
         });
     };
 
-    ERROR($EVAL_ERROR)                                   if ($EVAL_ERROR);
+    ERROR($@)                                   if ($@);
     ERROR("Node side timeout while processing: '$line'") if ($timed_out);
 
     return;
@@ -196,8 +196,8 @@ sub _process_command_line {
         eval {
             $session->{tls_started} = _process_starttls_command($session);
         };
-        if ($EVAL_ERROR) {
-            ERROR($EVAL_ERROR);
+        if ($@) {
+            ERROR($@);
             return 0;
         }
         DEBUG ('DEBUG: Returned from starttls.') if $config->{DEBUG};
diff --git a/lib/Munin/Node/Service.pm b/lib/Munin/Node/Service.pm
index 5dbcc69cc5..5a71cc3a6f 100644
--- a/lib/Munin/Node/Service.pm
+++ b/lib/Munin/Node/Service.pm
@@ -223,8 +223,8 @@ sub change_real_and_effective_user_and_group
             Munin::Node::OS->set_effective_user_id($uid)    unless $uid  == $root_uid;
         };
 
-        if ($EVAL_ERROR) {
-            CRITICAL("# FATAL: Plugin '$service' Can't drop privileges: $EVAL_ERROR.");
+        if ($@) {
+            CRITICAL("# FATAL: Plugin '$service' Can't drop privileges: $@.");
             exit 1;
         }
     }
diff --git a/lib/Munin/Plugin.pm b/lib/Munin/Plugin.pm
index 7cc5d2fbff..89e136d8b1 100644
--- a/lib/Munin/Plugin.pm
+++ b/lib/Munin/Plugin.pm
@@ -304,7 +304,7 @@ sub restore_state {
 	my @state;
 	# Protects _restore_state_raw() with an eval()
 	eval { @state = _restore_state_raw(); };
-	if ($EVAL_ERROR) { @state = (); warn $EVAL_ERROR; }
+	if ($@) { @state = (); warn $@; }
 
 	return _decode_state(@state);
 }
diff --git a/script/munin-node-configure b/script/munin-node-configure
index c981564ad5..21b713c95b 100755
--- a/script/munin-node-configure
+++ b/script/munin-node-configure
@@ -317,7 +317,7 @@ sub init_snmp
 {
     unless (eval { require Munin::Node::SNMPConfig; }) {
         die "# ERROR: Cannot perform SNMP probing as Munin::Node::SNMPConfig module is not available.\n",
-            $EVAL_ERROR;
+            $@;
     }
     return Munin::Node::SNMPConfig->new(@_);
 }

From c9d904c91397b197e8e15f3aa795a66ba3d1cbe6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>
Date: Mon, 20 Aug 2018 21:20:15 +0200
Subject: [PATCH 10/10] [perlcritic] allow usage of $$

---
 .perlcriticrc                    |  2 +-
 lib/Munin/Common/Logger.pm       |  4 +---
 lib/Munin/Master/LimitsOld.pm    |  2 +-
 lib/Munin/Master/UpdateWorker.pm |  2 +-
 lib/Munin/Master/Utils.pm        |  4 ++--
 script/munin-asyncd              | 22 +++++++++++-----------
 6 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/.perlcriticrc b/.perlcriticrc
index 969e74e975..ea6efc689a 100644
--- a/.perlcriticrc
+++ b/.perlcriticrc
@@ -16,7 +16,7 @@ profile-strictness = quiet
 
 [Variables::ProhibitPunctuationVars]
 severity = 5
-allow = $_ $! $0 $@
+allow = $_ $! $0 $@ $$
 
 [CodeLayout::RequireTidyCode]
 perltidyrc = perltidyrc
diff --git a/lib/Munin/Common/Logger.pm b/lib/Munin/Common/Logger.pm
index 2bb2d5132b..2ff0ce5e0f 100644
--- a/lib/Munin/Common/Logger.pm
+++ b/lib/Munin/Common/Logger.pm
@@ -20,8 +20,6 @@ our @EXPORT
 use Params::Validate qw(validate SCALAR);
 use POSIX;
 
-use English qw(-no_match_vars);
-
 sub _program_name {
     my @path = split( '/', $0 );
     return $path[-1];
@@ -49,7 +47,7 @@ my $screen_format = sub {
 
     chomp $message;
 
-    return sprintf( "%s [%s][%06d]: %s\n", _timestamp, $level, $PID, $message );
+    return sprintf( "%s [%s][%06d]: %s\n", _timestamp, $level, $$, $message );
 };
 
 my $file_format = $screen_format;
diff --git a/lib/Munin/Master/LimitsOld.pm b/lib/Munin/Master/LimitsOld.pm
index 1969983a9a..ccd9c46dd7 100644
--- a/lib/Munin/Master/LimitsOld.pm
+++ b/lib/Munin/Master/LimitsOld.pm
@@ -784,7 +784,7 @@ sub generate_service_message {
                 # See https://github.com/munin-monitoring/munin/issues/382
                 # and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=291168.
                 close(STDOUT);
-                exec($cmd) or WARN "[WARNING] Failed to exec for contact $c in pid $PID";
+                exec($cmd) or WARN "[WARNING] Failed to exec for contact $c in pid $$";
                 exit;
             }
         }
diff --git a/lib/Munin/Master/UpdateWorker.pm b/lib/Munin/Master/UpdateWorker.pm
index 18627323e9..2652a549b9 100644
--- a/lib/Munin/Master/UpdateWorker.pm
+++ b/lib/Munin/Master/UpdateWorker.pm
@@ -85,7 +85,7 @@ sub do_work {
 	# Having a local handle looks easier
 	my $node = $self->{node};
 
-    INFO "[INFO] starting work in $PID for $nodedesignation.\n";
+    INFO "[INFO] starting work in $$ for $nodedesignation.\n";
     my $done = $node->do_in_session(sub {
 
 	# A I/O timeout results in a violent exit.  Catch and handle.
diff --git a/lib/Munin/Master/Utils.pm b/lib/Munin/Master/Utils.pm
index 368b8c0b91..48fd9324f4 100644
--- a/lib/Munin/Master/Utils.pm
+++ b/lib/Munin/Master/Utils.pm
@@ -128,8 +128,8 @@ sub munin_getlock {
         seek(LOCK, 0, 0);
     }
     DEBUG "[DEBUG] Writing out PID to lock file $lockname";
-    print LOCK $PID; # we want the pid inside for later use
-    if (defined($pid) && length $PID < length $pid) {
+    print LOCK $$; # we want the pid inside for later use
+    if (defined($pid) && length $$ < length $pid) {
 	# Since pid was defined we need to truncate in case len($) < len($pid)
 	truncate(LOCK, tell(LOCK))
     }
diff --git a/script/munin-asyncd b/script/munin-asyncd
index 72201a9a57..cf834340ed 100755
--- a/script/munin-asyncd
+++ b/script/munin-asyncd
@@ -130,7 +130,7 @@ my $process_name = "main";
 
 my $plugins = {};
 {
-	INFO("[$PID][$process_name] Reading config from $host");
+	INFO("[$$][$process_name] Reading config from $host");
 	my $sock = new IO::Socket::INET(
 		PeerAddr	=> "$host",
 		Proto	=> 'tcp'
@@ -207,7 +207,7 @@ MAIN: while($keepgoing) {
 				$when_next = $should_be_next;
 			}
 
-			DEBUG("[$PID][$process_name] $plugin: should_have_been $should_have_been (" .
+			DEBUG("[$$][$process_name] $plugin: should_have_been $should_have_been (" .
 				localtime($should_have_been) .
 				"), should_be_next: $should_be_next (" .
 				localtime($should_be_next) .
@@ -250,10 +250,10 @@ MAIN: while($keepgoing) {
 	if ($sock)
 	{
 		if ( $sock->connected ) {
-			print STDERR "[$PID][$process_name][>] quit\n" if $verbose;
+			print STDERR "[$$][$process_name][>] quit\n" if $verbose;
 			print $sock "quit\n" ;
 		}
-		print STDERR "[$PID][$process_name] closing sock\n" if $verbose;
+		print STDERR "[$$][$process_name] closing sock\n" if $verbose;
 		$sock = undef;
 	}
 
@@ -267,14 +267,14 @@ MAIN: while($keepgoing) {
 	my $sleep_sec = $when_next - time;
 
 	if ($sleep_sec > 0) {
-		INFO("[$PID][$process_name] Sleeping $sleep_sec sec");
+		INFO("[$$][$process_name] Sleeping $sleep_sec sec");
 		sleep $sleep_sec;
 	} else {
-		INFO("[$PID][$process_name] Already late : should sleep $sleep_sec sec\n");
+		INFO("[$$][$process_name] Already late : should sleep $sleep_sec sec\n");
 	}
 }
 
-print STDERR "[$PID][$process_name] Exiting\n" if $verbose;
+print STDERR "[$$][$process_name] Exiting\n" if $verbose;
 
 sub fetch_data
 {
@@ -284,9 +284,9 @@ sub fetch_data
 	my $sock = shift;
 
 
-		print STDERR "[$PID][$process_name][>][$plugin] asking for config\n" if $verbose;
+		print STDERR "[$$][$process_name][>][$plugin] asking for config\n" if $verbose;
 
-		print STDERR "[$PID][$process_name][>][$plugin][sock] config $plugin\n" if $debug;
+		print STDERR "[$$][$process_name][>][$plugin][sock] config $plugin\n" if $debug;
 		print $sock "config $plugin\n";
 
 		my $is_dirtyconfig;
@@ -295,7 +295,7 @@ sub fetch_data
 
 		while(my $line = <$sock>) {
 			chomp($line);
-			print STDERR "[$PID][$process_name][<][$plugin][sock] $line\n" if $debug;
+			print STDERR "[$$][$process_name][<][$plugin][sock] $line\n" if $debug;
 
 			if ($line =~ m/^\./) {
 				# Starting with . => end
@@ -322,7 +322,7 @@ sub fetch_data
 		# if dirty config, bypass the "fetch" part
 		goto WRITE_SPOOL if $is_dirtyconfig;
 
-		INFO("[$PID][$process_name][>][$plugin] asking for data\n");
+		INFO("[$$][$process_name][>][$plugin] asking for data\n");
                 DEBUG("[sock][>][$plugin] fetch $plugin\n");
 		print $sock "fetch $plugin\n";