diff --git a/plugins/ceph/ceph_osd b/plugins/ceph/ceph_osd
index 03b4b77d..4e5404de 100755
--- a/plugins/ceph/ceph_osd
+++ b/plugins/ceph/ceph_osd
@@ -6,6 +6,10 @@
 
 ceph_osd - Shows ceph OSD states (total configured, up and in)
 
+=head1 APPLICABLE SYSTEMS
+
+Any host with ceph configured and "jq" being installed .
+
 =head1 AUTHOR
 
 Mate Gabri <mate@gabri.hu>
@@ -46,7 +50,6 @@ fi
 
 CEPH_STATUS=$(ceph -s --format=json)
 
-echo "osds.value $(echo $CEPH_STATUS | jq '.osdmap.osdmap.num_osds')"
-echo "up.value $(echo $CEPH_STATUS | jq '.osdmap.osdmap.num_up_osds')"
-echo "in.value $(echo $CEPH_STATUS | jq '.osdmap.osdmap.num_in_osds')"
-
+echo "osds.value $(echo "$CEPH_STATUS" | jq '.osdmap.osdmap.num_osds')"
+echo "up.value $(echo "$CEPH_STATUS" | jq '.osdmap.osdmap.num_up_osds')"
+echo "in.value $(echo "$CEPH_STATUS" | jq '.osdmap.osdmap.num_in_osds')"
diff --git a/plugins/jvm/jstat__gccount b/plugins/jvm/jstat__gccount
index 165b4118..a04eb638 100755
--- a/plugins/jvm/jstat__gccount
+++ b/plugins/jvm/jstat__gccount
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 #
 # Plugin for monitor JVM activity - GC Count -
 #
@@ -22,9 +22,10 @@
 #
 # Target:
 #
-#	Target Java Virtual Machine to monitor are:
-#	  Sun JDK 5.0 (http://java.sun.com/javase/) (default)
-#	  BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)
+#       Target Java Virtual Machine to monitor are:
+#         Sun JDK 5.0 (http://java.sun.com/javase/)
+#         Sun JDK 8.0 (http://java.sun.com/javase/)
+#         BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)
 #
 # Parameters:
 #
@@ -33,140 +34,74 @@
 # Config variables:
 #
 #       pidfilepath  - Which file path use. Defaults to '/var/run/jsvc.pid'
-#       javahome     - Defaults to '/usr/local/java/jdk'
+#       javahome     - override automatic detection of JRE directory
+#       graphtitle   - Title of the graph (defaults to PID file location)
 #
-DefaultPidFile="/var/run/jsvc.pid"
-DefaultJavaHome="/usr/local/java/jdk"
 
-#
-# Environment Variables
-#
-if [ -z "${pidfilepath}" ]; then
-  pidfilepath="${DefaultPidFile}"
-fi
+default_java_home=/usr/lib/jvm/default-java
+[ -e "$default_java_home" ] || default_java_home=/usr/local/java/jdk
 
-if [ -z "${graphtitle}" ]; then
-  graphtitle="${pidfilepath}"
-fi
+pidfilepath=${pidfilepath:-/var/run/jsvc.pid}
+graphtitle=${graphtitle:-$pidfilepath}
+JAVA_HOME=${javahome:-$default_java_home}
 
-if [ -z "${javahome}" ]; then
-  JAVA_HOME="${DefaultJavaHome}"
-else
-  JAVA_HOME="${javahome}"
-fi
 export JAVA_HOME
 
-#
-# Functions
-#
-chk_jdk()
-{
-  isJRockit=`${JAVA_HOME}/bin/java -version 2>&1 | egrep -i 'jrockit'`
-  if [ -n "${isJRockit}" ]; then
-    JDK_TYPE="bea"
-  else
-    JDK_TYPE="sun"
+
+get_jdk_type() {
+    local version
+    if "${JAVA_HOME}/bin/java" -version 2>&1 | grep -qi 'jrockit'; then
+        echo "bea"
+    else
+        version=$("${JAVA_HOME}/bin/java" -version 2>&1 | grep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1)
+        if echo "$version" | grep -q '^1\.5\.'; then
+            echo "sun15"
+        else
+            echo "sun"
+        fi
   fi
 }
 
-chk_version()
-{
-  Version=`${JAVA_HOME}/bin/java -version 2>&1 | egrep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1`
-  if [ "${Version}" != "1.5.0" ]; then
-    return 1
-  else
-    return 0
-  fi
+
+print_config() {
+    echo "graph_title GC Count $graphtitle"
+    echo 'graph_args -l 0'
+    echo 'graph_vlabel GC Count(times)'
+    echo 'graph_total total'
+    echo 'graph_info GC Count'
+    echo 'graph_category virtualization'
+
+    echo 'Young_GC.label Young_GC'
+    echo 'Young_GC.min 0'
+    if [ "${JDK_TYPE}" = "bea" ]; then
+        echo 'Old_GC.label Old_GC'
+        echo 'Old_GC.min 0'
+    else
+        echo 'Full_GC.label Full_GC'
+        echo 'Full_GC.min 0'
+    fi
 }
 
-config_common()
-{
-  echo 'graph_title GC Count' $graphtitle
-  echo 'graph_args -l 0'
-  echo 'graph_vlabel GC Count(times)'
-  echo 'graph_total total'
-  echo 'graph_info GC Count'
-  echo 'graph_category virtualization'
+
+print_stats() {
+    local pid_num="$1"
+    local awk_script
+    if [ "${JDK_TYPE}" = "bea" ]; then
+        # shellcheck disable=SC2016
+        awk_script='{ YC = $4; OC = $5; print "Young_GC.value " YGC; print "Old_GC.value " FGC; }'
+    elif [ "${JDK_TYPE}" = "sun15" ]; then
+        # shellcheck disable=SC2016
+        awk_script='{ YGC = $11; FGC = $13; print "Young_GC.value " YGC; print "Full_GC.value " FGC; }'
+    else
+        # example output of jstat for Java 1.8:
+        #   S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT
+        #   2048.0 2048.0 0.0 1344.0 694784.0 145013.5 1398272.0 414857.1 102400.0 96308.0 12544.0 11240.1 979 20.997 5 2.705 23.702
+        # shellcheck disable=SC2016
+        awk_script='{ YGC = $13; FGC = $15; print "Young_GC.value " YGC; print "Full_GC.value " FGC; }'
+    fi
+    "${JAVA_HOME}/bin/jstat" -gc "$pid_num" | tail -1 | awk "$awk_script"
 }
 
-config_sun_jdk()
-{
-  config_common
-
-  echo 'Young_GC.label Young_GC'
-  echo 'Young_GC.min 0'
-  echo 'Full_GC.label Full_GC'
-  echo 'Full_GC.min 0'
-
-}
-
-config_bea_jdk()
-{
-  config_common
-
-  echo 'Young_GC.label Young_GC'
-  echo 'Young_GC.min 0'
-  echo 'Old_GC.label Old_GC'
-  echo 'Old_GC.min 0'
-}
-
-print_sun_stats()
-{
-${JAVA_HOME}/bin/jstat -gc ${PidNum} | tail -1 | awk \
-'{\
-        S0C = $1; \
-        S1C = $2; \
-        S0U = $3; \
-        S1U = $4; \
-        EC  = $5; \
-        EU  = $6; \
-        OC  = $7; \
-        OU  = $8; \
-        PC  = $9; \
-        PU  = $10; \
-        YGC  = $11; \
-        YGCT  = $12; \
-        FGC  = $13; \
-        FGCT  = $14; \
-        GCT  = $15; \
-        \
-        S0F = S0C - S0U; \
-        S1F = S1C - S1U; \
-        EF  = EC  - EU;  \
-        OF  = OC  - OU;  \
-        PF  = PC  - PU;  \
-        \
-        print "Young_GC.value " YGC; \
-        print "Full_GC.value " FGC; \
-}'
-}
-
-print_bea_stats()
-{
-${JAVA_HOME}/bin/jstat -gc ${PidNum} | tail -1 | awk \
-'{\
-	HeapSize = $1; \
-	NurserySize = $2; \
-	UsedHeapSize = $3; \
-	YC = $4; \
-	OC = $5; \
-	YCTime = $6; \
-	OCTime = $7; \
-	GCTime = $8; \
-	YCPauseTime = $9; \
-	OCPauseTime = $10; \
-	PauseTime = $11; \
-	Finalizers = $12; \
-	\
-	print "Young_GC.value " YC; \
-	print "Old_GC.value " OC;\
-}'
-}
-
-#
-# common for all argument
-#
-chk_jdk
 
 #
 # autoconf
@@ -178,13 +113,7 @@ if [ "$1" = "autoconf" ]; then
     exit 1
   fi
 
-  chk_version
-  if [ $? != 0 ]; then
-    echo "no (Java version is invalid)"
-    exit 1
-  fi
-
-  if [ ! -f "${pidfilepath}" -o ! -r "${pidfilepath}" ]; then
+  if [ ! -f "${pidfilepath}" ] || [ ! -r "${pidfilepath}" ]; then
     echo "no (No such file ${pidfilepath} or cannot read ${pidfilepath}"
     exit 1
   fi
@@ -194,25 +123,12 @@ if [ "$1" = "autoconf" ]; then
 fi
 
 
-#
-# config
-#
+JDK_TYPE=$(get_jdk_type)
+
+
 if [ "$1" = "config" ]; then
-  if [ "${JDK_TYPE}" == "bea" ]; then
-    config_bea_jdk
-  else
-    config_sun_jdk
-  fi
-  exit 0
+    print_config
+    exit 0
 fi
 
-#
-# Main
-#
-PidNum=`cat ${pidfilepath}`
-
-if [ "${JDK_TYPE}" == "bea" ]; then
-  print_bea_stats
-else
-  print_sun_stats
-fi
+print_stats "$(cat "$pidfilepath")"
diff --git a/plugins/jvm/jstat__gctime b/plugins/jvm/jstat__gctime
index de221292..7326b46b 100755
--- a/plugins/jvm/jstat__gctime
+++ b/plugins/jvm/jstat__gctime
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 #
 # Plugin for monitor JVM activity - GC Time -
 #
@@ -22,9 +22,10 @@
 #
 # Target:
 #
-#	Target Java Virtual Machine to monitor are:
-#	  Sun JDK 5.0 (http://java.sun.com/javase/) (default)
-#	  BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)
+#       Target Java Virtual Machine to monitor are:
+#         Sun JDK 5.0 (http://java.sun.com/javase/)
+#         Sun JDK 8.0 (http://java.sun.com/javase/)
+#         BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)
 #
 # Parameters:
 #
@@ -33,148 +34,94 @@
 # Config variables:
 #
 #       pidfilepath  - Which file path use. Defaults to '/var/run/jsvc.pid'
-#       javahome     - Defaults to '/usr/local/java/jdk'
+#       javahome     - override automatic detection of JRE directory
+#       graphtitle   - Title of the graph (defaults to PID file location)
 #
-DefaultPidFile="/var/run/jsvc.pid"
-DefaultJavaHome="/usr/local/java/jdk"
 
-#
-# Environment Variables
-#
-if [ -z "${pidfilepath}" ]; then
-  pidfilepath="${DefaultPidFile}"
-fi
+default_java_home=/usr/lib/jvm/default-java
+[ -e "$default_java_home" ] || default_java_home=/usr/local/java/jdk
 
-if [ -z "${graphtitle}" ]; then
-  graphtitle="${pidfilepath}"
-fi
+pidfilepath=${pidfilepath:-/var/run/jsvc.pid}
+graphtitle=${graphtitle:-$pidfilepath}
+JAVA_HOME=${javahome:-$default_java_home}
 
-if [ -z "${javahome}" ]; then
-  JAVA_HOME="${DefaultJavaHome}"
-else
-  JAVA_HOME="${javahome}"
-fi
 export JAVA_HOME
 
-#
-# Functions
-#
-chk_jdk()
-{
-  isJRockit=`${JAVA_HOME}/bin/java -version 2>&1 | egrep -i 'jrockit'`
-  if [ -n "${isJRockit}" ]; then
-    JDK_TYPE="bea"
-  else
-    JDK_TYPE="sun"
+
+get_jdk_type() {
+    local version
+    if "${JAVA_HOME}/bin/java" -version 2>&1 | grep -qi 'jrockit'; then
+        echo "bea"
+    else
+        version=$("${JAVA_HOME}/bin/java" -version 2>&1 | grep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1)
+        if echo "$version" | grep -q '^1\.5\.'; then
+            echo "sun15"
+        else
+            echo "sun"
+        fi
   fi
 }
 
-chk_version()
-{
-  Version=`${JAVA_HOME}/bin/java -version 2>&1 | egrep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1`
-  if [ "${Version}" != "1.5.0" ]; then
-    return 1
-  else
-    return 0
-  fi
+
+print_config() {
+    echo "graph_title GC Time $graphtitle"
+    echo 'graph_args -l 0'
+    echo 'graph_vlabel GC Time(sec)'
+    echo 'graph_total total'
+    echo 'graph_info GC Time'
+    echo 'graph_category virtualization'
+
+    echo 'Young_GC.label Young_GC'
+    echo 'Young_GC.min 0'
+    if [ "${JDK_TYPE}" = "bea" ]; then
+        echo 'Old_GC.label Old_GC'
+        echo 'Old_GC.min 0'
+        echo 'Young_Pause.label Young_GC Pause'
+        echo 'Young_Pause.min 0'
+        echo 'Old_Pause.label Old_GC Pause'
+        echo 'Old_Pause.min 0'
+    else
+        echo 'Full_GC.label Full_GC'
+        echo 'Full_GC.min 0'
+    fi
 }
 
-config_common()
-{
-        echo 'graph_title GC Time' $graphtitle
-        echo 'graph_args -l 0'
-        echo 'graph_vlabel GC Time(sec)'
-        echo 'graph_total total'
-        echo 'graph_info GC Time'
-        echo 'graph_category virtualization'
+
+print_stats() {
+    local pid_num="$1"
+    local awk_script
+    if [ "${JDK_TYPE}" = "bea" ]; then
+        # shellcheck disable=SC2016
+        awk_script='{
+            YCTime = $6;
+            OCTime = $7;
+            YCPauseTime = $9;
+            OCPauseTime = $10;
+            print "Young_GC.value " YCTime;
+            print "Old_GC.value " OCTime;
+            print "Young_Pause.value " YCPauseTime;
+            print "Old_Pause.value " OCPauseTime; }'
+    elif [ "${JDK_TYPE}" = "sun15" ]; then
+        # shellcheck disable=SC2016
+        awk_script='{
+            YGCT  = $12;
+            FGCT  = $14;
+            print "Young_GC.value " YGCT;
+            print "Full_GC.value " FGCT; }'
+    else
+        # example output of jstat for Java 1.8:
+        #   S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT
+        #   2048.0 2048.0 0.0 1344.0 694784.0 145013.5 1398272.0 414857.1 102400.0 96308.0 12544.0 11240.1 979 20.997 5 2.705 23.702
+        # shellcheck disable=SC2016
+        awk_script='{
+            YGCT  = $14;
+            FGCT  = $16;
+            print "Young_GC.value " YGCT;
+            print "Full_GC.value " FGCT; }'
+    fi
+    "${JAVA_HOME}/bin/jstat" -gc "$pid_num" | tail -1 | awk "$awk_script"
 }
 
-config_sun_jdk()
-{
-  config_common
-
-  echo 'Young_GC.label Young_GC'
-  echo 'Young_GC.min 0'
-  echo 'Full_GC.label Full_GC'
-  echo 'Full_GC.min 0'
-
-}
-
-config_bea_jdk()
-{
-  config_common
-
-  echo 'Young_GC.label Young_GC'
-  echo 'Young_GC.min 0'
-  echo 'Old_GC.label Old_GC'
-  echo 'Old_GC.min 0'
-  echo 'Young_Pause.label Young_GC Pause'
-  echo 'Young_Pause.min 0'
-  echo 'Old_Pause.label Old_GC Pause'
-  echo 'Old_Pause.min 0'
-
-}
-
-print_sun_stats()
-{
-${JAVA_HOME}/bin/jstat -gc ${PidNum} | tail -1 | awk \
-'{\
-	S0C = $1; \
-	S1C = $2; \
-	S0U = $3; \
-	S1U = $4; \
-	EC  = $5; \
-	EU  = $6; \
-	OC  = $7; \
-	OU  = $8; \
-	PC  = $9; \
-	PU  = $10; \
-        YGC  = $11; \
-        YGCT  = $12; \
-        FGC  = $13; \
-        FGCT  = $14; \
-        GCT  = $15; \
-
-	\
-	S0F = S0C - S0U; \
-	S1F = S1C - S1U; \
-	EF  = EC  - EU;  \
-	OF  = OC  - OU;  \
-	PF  = PC  - PU;  \
-	\
-        print "Young_GC.value " YGCT; \
-        print "Full_GC.value " FGCT; \
-}'
-}
-
-print_bea_stats()
-{
-${JAVA_HOME}/bin/jstat -gc ${PidNum} | tail -1 | awk \
-'{\
-	HeapSize = $1; \
-	NurserySize = $2; \
-	UsedHeapSize = $3; \
-	YC = $4; \
-	OC = $5; \
-	YCTime = $6; \
-	OCTime = $7; \
-	GCTime = $8; \
-	YCPauseTime = $9; \
-	OCPauseTime = $10; \
-	PauseTime = $11; \
-	Finalizers = $12; \
-	\
-	print "Young_GC.value " YCTime; \
-	print "Old_GC.value " OCTime; \
-	print "Young_Pause.value " YCPauseTime; \
-	print "Old_Pause.value " OCPauseTime
-}'
-}
-
-#
-# common for all argument
-#
-chk_jdk
 
 #
 # autoconf
@@ -186,13 +133,7 @@ if [ "$1" = "autoconf" ]; then
     exit 1
   fi
 
-  chk_version
-  if [ $? != 0 ]; then
-    echo "no (Java version is invalid)"
-    exit 1
-  fi
-
-  if [ ! -f "${pidfilepath}" -o ! -r "${pidfilepath}" ]; then
+  if [ ! -f "${pidfilepath}" ] || [ ! -r "${pidfilepath}" ]; then
     echo "no (No such file ${pidfilepath} or cannot read ${pidfilepath}"
     exit 1
   fi
@@ -202,25 +143,11 @@ if [ "$1" = "autoconf" ]; then
 fi
 
 
-#
-# config
-#
+JDK_TYPE=$(get_jdk_type)
+
+
 if [ "$1" = "config" ]; then
-  if [ "${JDK_TYPE}" == "bea" ]; then
-    config_bea_jdk
-  else
-    config_sun_jdk
-  fi
-  exit 0
+    print_config
 fi
 
-#
-# Main
-#
-PidNum=`cat ${pidfilepath}`
-
-if [ "${JDK_TYPE}" == "bea" ]; then
-  print_bea_stats
-else
-  print_sun_stats
-fi
+print_stats "$(cat "$pidfilepath")"
diff --git a/plugins/jvm/jstat__heap b/plugins/jvm/jstat__heap
index c4c4c33a..edf6f411 100755
--- a/plugins/jvm/jstat__heap
+++ b/plugins/jvm/jstat__heap
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 #
 # Plugin for monitor JVM activity - Heap Usage -
 #
@@ -22,9 +22,10 @@
 #
 # Target:
 #
-#	Target Java Virtual Machine to monitor are:
-#	  Sun JDK 5.0 (http://java.sun.com/javase/) (default)
-#	  BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)
+#       Target Java Virtual Machine to monitor are:
+#         Sun JDK 5.0 (http://java.sun.com/javase/)
+#         Sun JDK 8.0 (http://java.sun.com/javase/)
+#         BEA JRockit 5.0 (http://dev2dev.bea.com/jrockit/)
 #
 # Parameters:
 #
@@ -33,160 +34,149 @@
 # Config variables:
 #
 #       pidfilepath  - Which file path use. Defaults to '/var/run/jsvc.pid'
-#       javahome     - Defaults to '/usr/local/java/jdk'
+#       javahome     - override automatic detection of JRE directory
+#       graphtitle   - Title of the graph (defaults to PID file location)
 #
-DefaultPidFile="/var/run/jsvc.pid"
-DefaultJavaHome="/usr/local/java/jdk"
 
-#
-# Environment Variables
-#
-if [ -z "${pidfilepath}" ]; then
-  pidfilepath="${DefaultPidFile}"
-fi
+default_java_home=/usr/lib/jvm/default-java
+[ -e "$default_java_home" ] || default_java_home=/usr/local/java/jdk
 
-if [ -z "${graphtitle}" ]; then
-  graphtitle="${pidfilepath}"
-fi
+pidfilepath=${pidfilepath:-/var/run/jsvc.pid}
+graphtitle=${graphtitle:-$pidfilepath}
+JAVA_HOME=${javahome:-$default_java_home}
 
-if [ -z "${javahome}" ]; then
-  JAVA_HOME="${DefaultJavaHome}"
-else
-  JAVA_HOME="${javahome}"
-fi
 export JAVA_HOME
 
-#
-# Functions
-#
-chk_jdk()
-{
-  isJRockit=`${JAVA_HOME}/bin/java -version 2>&1 | egrep -i 'jrockit'`
-  if [ -n "${isJRockit}" ]; then
-    JDK_TYPE="bea"
-  else
-    JDK_TYPE="sun"
+
+get_jdk_type() {
+    local version
+    if "${JAVA_HOME}/bin/java" -version 2>&1 | grep -qi 'jrockit'; then
+        echo "bea"
+    else
+        version=$("${JAVA_HOME}/bin/java" -version 2>&1 | grep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1)
+        if echo "$version" | grep -q '^1\.5\.'; then
+            echo "sun15"
+        else
+            echo "sun"
+        fi
   fi
 }
 
-chk_version()
-{
-  Version=`${JAVA_HOME}/bin/java -version 2>&1 | egrep '^java version' | awk '{print $3}' | sed -e 's/\"//g' | cut -d'_' -f 1`
-  if [ "${Version}" != "1.5.0" ]; then
-    return 1
-  else
-    return 0
-  fi
+
+print_config() {
+    echo "graph_title Heap Usage $graphtitle"
+    echo "graph_args --base 1024 -l 0"
+    echo "graph_vlabel Heap Usage(Bytes)"
+    echo "graph_info Heap Usage"
+    echo "graph_category virtualization"
+
+    if [ "${JDK_TYPE}" = "bea" ]; then
+        echo "NurserySize.label NurserySize"
+        echo "HeapSize.label HeapSize"
+        echo "UsedHeapSize.label UsedHeapSize"
+        echo "NurserySize.draw AREA"
+        echo "HeapSize.draw STACK"
+        echo "UsedHeapSize.draw STACK"
+    else
+        echo "Eden_Used.label Eden_Used"
+        echo "Eden_Free.label Eden_Free"
+        echo "Survivor0_Used.label Survivor0_Used"
+        echo "Survivor0_Free.label Survivor0_Free"
+        echo "Survivor1_Used.label Survivor1_Used"
+        echo "Survivor1_Free.label Survivor1_Free"
+        echo "Old_Used.label Old_Used"
+        echo "Old_Free.label Old_Free"
+        echo "Permanent_Used.label Permanent_Used"
+        echo "Permanent_Free.label Permanent_Free"
+        echo "Eden_Used.draw AREA"
+        echo "Eden_Free.draw STACK"
+        echo "Survivor0_Used.draw STACK"
+        echo "Survivor0_Free.draw STACK"
+        echo "Survivor1_Used.draw STACK"
+        echo "Survivor1_Free.draw STACK"
+        echo "Old_Used.draw STACK"
+        echo "Old_Free.draw STACK"
+        echo "Permanent_Used.draw STACK"
+        echo "Permanent_Free.draw STACK"
+    fi
 }
 
-config_common()
-{
-  echo "graph_title Heap Usage" $graphtitle
-  echo "graph_args --base 1024 -l 0"
-  echo "graph_vlabel Heap Usage(Bytes)"
-  echo "graph_info Heap Usage"
-  echo "graph_category virtualization"
+
+print_stats() {
+    local pid_num="$1"
+    local awk_script
+    if [ "${JDK_TYPE}" = "bea" ]; then
+        # shellcheck disable=SC2016
+        awk_script='{
+            HeapSize = $1;
+            NurserySize = $2;
+            UsedHeapSize = $3;
+            print "NurserySize.value " NurserySize * 1024;
+            print "HeapSize.value " HeapSize * 1024;
+            print "UsedHeapSize.value " UsedHeapSize * 1024; }'
+    elif [ "${JDK_TYPE}" = "sun15" ]; then
+        # shellcheck disable=SC2016
+        awk_script='{
+            S0C = $1;
+            S1C = $2;
+            S0U = $3;
+            S1U = $4;
+            EC  = $5;
+            EU  = $6;
+            OC  = $7;
+            OU  = $8;
+            PC  = $9;
+            PU  = $10;
+            S0F = S0C - S0U;
+            S1F = S1C - S1U;
+            EF  = EC  - EU;
+            OF  = OC  - OU;
+            PF  = PC  - PU;
+            print "Eden_Used.value " EU * 1024;
+            print "Eden_Free.value " EF * 1024;
+            print "Survivor0_Used.value " S0U * 1024;
+            print "Survivor0_Free.value " S0F * 1024;
+            print "Survivor1_Used.value " S1U * 1024;
+            print "Survivor1_Free.value " S1F * 1024;
+            print "Old_Used.value " OU * 1024;
+            print "Old_Free.value " OF * 1024;
+            print "Permanent_Used.value " PU * 1024;
+            print "Permanent_Free.value " PF * 1024; }'
+    else
+        # example output of jstat for Java 1.8:
+        #   S0C S1C S0U S1U EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT GCT
+        #   2048.0 2048.0 0.0 1344.0 694784.0 145013.5 1398272.0 414857.1 102400.0 96308.0 12544.0 11240.1 979 20.997 5 2.705 23.702
+        # shellcheck disable=SC2016
+        awk_script='{
+            S0C = $1;
+            S1C = $2;
+            S0U = $3;
+            S1U = $4;
+            EC  = $5;
+            EU  = $6;
+            OC  = $7;
+            OU  = $8;
+            MC  = $9;
+            MU  = $10;
+            S0F = S0C - S0U;
+            S1F = S1C - S1U;
+            EF  = EC  - EU;
+            OF  = OC  - OU;
+            MF  = MC  - MU;
+            print "Eden_Used.value " EU * 1024;
+            print "Eden_Free.value " EF * 1024;
+            print "Survivor0_Used.value " S0U * 1024;
+            print "Survivor0_Free.value " S0F * 1024;
+            print "Survivor1_Used.value " S1U * 1024;
+            print "Survivor1_Free.value " S1F * 1024;
+            print "Old_Used.value " OU * 1024;
+            print "Old_Free.value " OF * 1024;
+            print "Permanent_Used.value " PU * 1024;
+            print "Permanent_Free.value " MF * 1024; }'
+    fi
+    "${JAVA_HOME}/bin/jstat" -gc "$pid_num" | tail -1 | awk "$awk_script"
 }
 
-config_sun_jdk()
-{
-  config_common
-
-  echo "Eden_Used.label Eden_Used"
-  echo "Eden_Free.label Eden_Free"
-  echo "Survivor0_Used.label Survivor0_Used"
-  echo "Survivor0_Free.label Survivor0_Free"
-  echo "Survivor1_Used.label Survivor1_Used"
-  echo "Survivor1_Free.label Survivor1_Free"
-  echo "Old_Used.label Old_Used"
-  echo "Old_Free.label Old_Free"
-  echo "Permanent_Used.label Permanent_Used"
-  echo "Permanent_Free.label Permanent_Free"
-  echo "Eden_Used.draw AREA"
-  echo "Eden_Free.draw STACK"
-  echo "Survivor0_Used.draw STACK"
-  echo "Survivor0_Free.draw STACK"
-  echo "Survivor1_Used.draw STACK"
-  echo "Survivor1_Free.draw STACK"
-  echo "Old_Used.draw STACK"
-  echo "Old_Free.draw STACK"
-  echo "Permanent_Used.draw STACK"
-  echo "Permanent_Free.draw STACK"
-}
-
-config_bea_jdk()
-{
-  config_common
-
-  echo "NurserySize.label NurserySize"
-  echo "HeapSize.label HeapSize"
-  echo "UsedHeapSize.label UsedHeapSize"
-  echo "NurserySize.draw AREA"
-  echo "HeapSize.draw STACK"
-  echo "UsedHeapSize.draw STACK"
-}
-
-print_sun_stats()
-{
-${JAVA_HOME}/bin/jstat -gc ${PidNum} | tail -1 | awk \
-'{\
-	S0C = $1; \
-	S1C = $2; \
-	S0U = $3; \
-	S1U = $4; \
-	EC  = $5; \
-	EU  = $6; \
-	OC  = $7; \
-	OU  = $8; \
-	PC  = $9; \
-	PU  = $10; \
-	\
-	S0F = S0C - S0U; \
-	S1F = S1C - S1U; \
-	EF  = EC  - EU;  \
-	OF  = OC  - OU;  \
-	PF  = PC  - PU;  \
-	\
-	print "Eden_Used.value " EU * 1024; \
-	print "Eden_Free.value " EF * 1024; \
-	print "Survivor0_Used.value " S0U * 1024; \
-	print "Survivor0_Free.value " S0F * 1024; \
-	print "Survivor1_Used.value " S1U * 1024; \
-	print "Survivor1_Free.value " S1F * 1024; \
-	print "Old_Used.value " OU * 1024; \
-	print "Old_Free.value " OF * 1024; \
-	print "Permanent_Used.value " PU * 1024; \
-	print "Permanent_Free.value " PF * 1024; \
-}'
-}
-
-print_bea_stats()
-{
-${JAVA_HOME}/bin/jstat -gc ${PidNum} | tail -1 | awk \
-'{\
-	HeapSize = $1; \
-	NurserySize = $2; \
-	UsedHeapSize = $3; \
-	YC = $4; \
-	OC = $5; \
-	YCTime = $6; \
-	OCTime = $7; \
-	GCTime = $8; \
-	YCPauseTime = $9; \
-	OCPauseTime = $10; \
-	PauseTime = $11; \
-	Finalizers = $12; \
-	\
-	print "NurserySize.value " NurserySize * 1024; \
-	print "HeapSize.value " UsedHeapSize * 1024; \
-	print "UsedHeapSize.value " UsedHeapSize * 1024; \
-}'
-}
-
-#
-# common for all argument
-#
-chk_jdk
 
 #
 # autoconf
@@ -198,13 +188,7 @@ if [ "$1" = "autoconf" ]; then
     exit 1
   fi
 
-  chk_version
-  if [ $? != 0 ]; then
-    echo "no (Java version is invalid)"
-    exit 1
-  fi
-
-  if [ ! -f "${pidfilepath}" -o ! -r "${pidfilepath}" ]; then
+  if [ ! -f "${pidfilepath}" ] || [ ! -r "${pidfilepath}" ]; then
     echo "no (No such file ${pidfilepath} or cannot read ${pidfilepath}"
     exit 1
   fi
@@ -214,25 +198,11 @@ if [ "$1" = "autoconf" ]; then
 fi
 
 
-#
-# config
-#
+JDK_TYPE=$(get_jdk_type)
+
+
 if [ "$1" = "config" ]; then
-  if [ "${JDK_TYPE}" == "bea" ]; then
-    config_bea_jdk
-  else
-    config_sun_jdk
-  fi
-  exit 0
+    print_config
 fi
 
-#
-# Main
-#
-PidNum=`cat ${pidfilepath}`
-
-if [ "${JDK_TYPE}" == "bea" ]; then
-  print_bea_stats
-else
-  print_sun_stats
-fi
+print_stats "$(cat "$pidfilepath")"