fix empty value in performance data; shell fixes

check_snmp_data

@@ -38,15 +38,19 @@
 # DATA:disc:data:disc-space:1.3.6.1.4.1.6574.3.1.1.2::1.3.6.1.4.1.6574.3.1.1.5
 #
 # ----------------------------------------------------------------------
-# 2020-08-11  <axel.hahn@iml.unibe.ch>  initial version
-# 2020-08-13  <axel.hahn@iml.unibe.ch>  add host in label for counter data
-# 2022-10-21  v0.4  <axel.hahn@unibe.ch>     remove grep: warning: stray \ before white space
+# 2020-08-11  <axel.hahn@iml.unibe.ch>            initial version
+# 2020-08-13  <axel.hahn@iml.unibe.ch>            add host in label for counter data
+# 2022-10-21  v0.4  <axel.hahn@unibe.ch>          remove grep: warning: stray \ before white space
+# 2022-10-21  v0.5  <andrea.gottsponer@unibe.ch>  remove grep: warning: stray \ before white space
+# 2022-10-25  v0.6  <axel.hahn@unibe.ch>          fix empty value in performance data; shell fixes
 # ======================================================================
 
-. `dirname $0`/inc_pluginfunctions
+. $(dirname $0)/inc_pluginfunctions
 
 # --- basic vars
-ABOUT="SNMP performance data v0.4"
+self_APPNAME=$( basename $0 | tr [:lower:] [:upper:] )
+self_APPVERSION=0.6
+
 SNMPCOMMUNITY="public"
 SNMPVERSION="2c"
 SNMPWALK=$(which snmpwalk)
@@ -125,14 +129,18 @@ _iscounter(){
 
 #---------------------------------------------------
 # --- show usage
-usage()
-{
-    cat <<EOH
+function showHelp(){
+cat <<EOH
+______________________________________________________________________
+
+$self_APPNAME 
+v$self_APPVERSION
 
-$ABOUT
+(c) Institute for Medical Education - University of Bern
+Licence: GNU GPL 3
+______________________________________________________________________
 
-University of Bern * Institute of Medical Education
-GNU GPL 3.0
+SNMP performance data of Synology storages.
 
 USAGE:
     ./check_snmp_data -h hostname [-C communitystring] -m method
@@ -146,11 +154,11 @@ PARAMETERS:
 EOH
 
     # --- dynamic: add current methods
-    _cfg_getMethods | while read line
+    _cfg_getMethods | while read -r line
     do
-        METHOD=`echo $line | cut -f 1 -d ":"`
+        METHOD=$(echo "$line" | cut -f 1 -d ":")
         descr=$(_cfg_getlabel)
-        printf "                          %-10s %-50s\n" $METHOD "$descr"
+        printf "                          %-10s %-50s\n" "$METHOD" "$descr"
     done
 
     # --- finish usage
@@ -199,8 +207,8 @@ fi
 # --- read metadata of the selected METHOD
 info=$(_cfg_getlabel)
 if [ -z "$info" ]; then
-    echo ERROR: unknown METHOD [$METHOD]
-    usage
+    echo "ERROR: unknown METHOD [$METHOD]"
+    showHelp
 fi
 
 prflist=( $(_cfg_dataitem 4) )
@@ -210,14 +218,14 @@ looplist=( $(_cfg_dataitem 7) )
 
 # --- check for looplist
 if [ -n "$looplist" ]; then
-  nb=`$SNMPWALK -OQne -t 10 -v $SNMPVERSION -c $SNMPCOMMUNITY $HOSTNAME ${oidlist[*]} 2> /dev/null | wc -l`
+  nb=$($SNMPWALK -OQne -t 10 -v $SNMPVERSION -c $SNMPCOMMUNITY $HOSTNAME ${oidlist[*]} 2> /dev/null | wc -l)
 
   declare -a tmpPrflist=()
   declare -a tmpOidlist=()
   declare -a tmpUnitlist=()
-  for i in `seq 1 $nb`;
+  for i in $(seq 1 $nb);
   do
-    for j in `seq 1 ${#looplist[@]}`
+    for j in $(seq 1 ${#looplist[@]})
     do
       tmpPrflist+=("${prflist[$(($j-1))]}.$(($i-1))")
       tmpOidlist+=("${looplist[$(($j-1))]}.$(($i-1))")
@@ -230,7 +238,7 @@ if [ -n "$looplist" ]; then
 fi
 
 # --- SNMPGET to all wanted oids
-SYNO=`$SNMPGET -One -t 10 -v $SNMPVERSION -c $SNMPCOMMUNITY $HOSTNAME ${oidlist[*]} 2> /dev/null`
+SYNO=$($SNMPGET -One -t 10 -v $SNMPVERSION -c $SNMPCOMMUNITY $HOSTNAME ${oidlist[*]} 2> /dev/null)
 
 if [ $? -ne 0 ] ; then
     $SNMPGET -One -t 10 -v $SNMPVERSION -c $SNMPCOMMUNITY $HOSTNAME ${oidlist[*]}
@@ -239,6 +247,8 @@ fi
 
 
 # --- performance data
+typeset -i value
+
 for index in ${!oidlist[*]}
 do
     label="${prflist[$index]}"
@@ -251,7 +261,7 @@ do
     else
       # handle counter data
       if [ "$(_iscounter ${oidlist[$index]})" = "true" ]; then
-          value2=`ph.perfdeltaspeed "snmp-data-${HOSTNAME}-${method}-${label}" $value`
+          value2=$(ph.perfdeltaspeed "snmp-data-${HOSTNAME}-${method}-${label}" $value)
           _wd "$( printf '%-14s total: %-14s delta: %6s %s per sec' $label $value $value2 $unit )"
           value=$value2
       else