diff --git a/xCAT-server/share/xcat/scripts/xHRM b/xCAT-server/share/xcat/scripts/xHRM
index 9b8dc8576..64d015911 100755
--- a/xCAT-server/share/xcat/scripts/xHRM
+++ b/xCAT-server/share/xcat/scripts/xHRM
@@ -1,6 +1,6 @@
-#!/bin/bash  
-if [ "$(uname -s|tr 'A-Z' 'a-z')" = "linux" ];then
-   str_dir_name=`dirname $0`
+#!/bin/bash
+if [ "$(uname -s|tr '[:upper:]' '[:lower:]')" = "linux" ];then
+   str_dir_name=$(dirname $0)
    . $str_dir_name/xcatlib.sh
 fi
 #written in bash for fewest prerequisites
@@ -9,35 +9,35 @@ function get_def_interface {
     #are in bash, the best alternative is to use ping to get at it
     #don't want to grep in /etc/hosts or presume DNS
     #we are, however, presuming ipv4 for the moment
-    retval=$(ping -c 1 `hostname`|head -n 1|cut -d\( -f 2|cut -d\) -f 1)
+    retval=$(ping -c 1 "$(hostname)"|head -n 1|cut -d\( -f 2|cut -d\) -f 1)
     if [ -z "$retval" -o "127.0.0.1" = "$retval" ]; then #ok, that didn't pan out, now we grab the first address that looks sane
         #retval=`ifconfig|grep inet" " |grep -v addr:127.0.0.1|grep -v 'addr:169.254'|head -n 1|cut -d: -f 2|cut -d' ' -f 1`
-        retval=`ip -4 -oneline addr show|grep -v "127.0.0.1"|grep -v '169.254'|head -n 1|awk -F 'inet ' '{print $2}'|awk -F '/' '{print $1}'`
+        retval=$(ip -4 -oneline addr show|grep -v "127.0.0.1"|grep -v '169.254'|head -n 1|awk -F 'inet ' '{print $2}'|awk -F '/' '{print $1}')
     fi
     if [ -z "$retval" ]; then 
         echo "ERROR: Unable to reasonably guess the 'default' interface" >&2
         exit 1
     fi
     #iface=`ifconfig|grep -v inet6|egrep '(Link|inet)'|grep -B1 'addr:'$retval |head -n 1|awk '{print $1}'`
-    iface=`ip -4 -oneline addr show|grep -i $retval|awk -F ':' '{print $2}'|awk -F ' ' '{print $1}'|grep -o "[^ ]\+\( \+[^ ]\+\)*"`
+    iface=$(ip -4 -oneline addr show|grep -i $retval|awk -F ':' '{print $2}'|awk -F ' ' '{print $1}'|grep -o "[^ ]\+\( \+[^ ]\+\)*")
     if [ -z "$iface" ]; then
         echo "ERROR: Unable to reasonably guess the default interface" >&2
         exit 1
     fi
-    if brctl show | grep ^$iface >& /dev/null; then #
+    if brctl show | grep ^$iface &> /dev/null; then #
         OIFS=$IFS
         IFS=$'\n'
         INMATCH=0
         for brline in $(brctl show); do
             IFS=$OIFS
-            if [ $(expr match "$brline" $iface) == $(expr length $iface) ]; then
+            if [ "$(expr match "$brline" $iface)" == ${#iface} ]; then
                 INMATCH=1
-                elif [ $(expr match "$brline" " ") != 1 ]; then
+            elif [ "$(expr match "$brline" " ")" != 1 ]; then
                 INMATCH=0
             fi
             if [ "$INMATCH" == 1 ];  then
-                if ! ethtool -i `echo $brline|awk '{print $NF}'`|grep "driver: tun" >& /dev/null; then
-                    iface=`echo $brline|awk '{print $NF}'`
+                if ! ethtool -i "$(echo $brline|awk '{print $NF}')"|grep "driver: tun" >& /dev/null; then
+                    iface=$(echo $brline|awk '{print $NF}')
                     echo "$iface"
                     IFS=$OFIS
                     return
@@ -60,7 +60,7 @@ function debianpreconf(){
         mkdir -p "/etc/network/interfaces.d"
     fi
     #search xcat flag
-    XCATFLAG=`grep "#XCAT_CONFIG" /etc/network/interfaces`
+    XCATFLAG=$(grep "#XCAT_CONFIG" /etc/network/interfaces)
     if [ -n "$XCATFLAG" ];then
         return
     fi
@@ -77,8 +77,7 @@ function debianpreconf(){
     CONFFILE=''
 
     #read the backfile
-    cat /etc/network/interfaces.bak | while read LINE
-    do
+    while read LINE; do
         if [ ! "$LINE" ];then
             continue
         fi
@@ -87,7 +86,7 @@ function debianpreconf(){
             continue
         fi
 
-        CONFTYPE=`echo $LINE | cut -d" " -f1`
+        CONFTYPE=$(echo $LINE | cut -d" " -f1)
         if [ $CONFTYPE = 'auto' -o $CONFTYPE = 'allow-hotplug' ];then
             LINE=${LINE#$CONFTYPE}
             for NICNAME in $LINE; do
@@ -95,7 +94,7 @@ function debianpreconf(){
             done
         elif [ $CONFTYPE = 'iface' -o $CONFTYPE = 'mapping' ];then
             #find out the nic name, should think about the eth0:1
-            NICNAME=`echo $LINE | cut -d" " -f 2 | cut -d":" -f 1`
+            NICNAME=$(echo $LINE | cut -d" " -f 2 | cut -d":" -f 1)
             CONFFILE="/etc/network/interfaces.d/$NICNAME"
             if [ ! -e $CONFFILE ];then
                 echo "auto $NICNAME" > $CONFFILE
@@ -107,13 +106,13 @@ function debianpreconf(){
             echo $LINE >> $CONFFILE
         fi
 
-    done
+    done </etc/network/interfaces.bak
 }
 
 if [ "storageprereq" = "$1"  ]; then
     MOUNTURI="$2"
-    DIRNAME=`echo $MOUNTURI|sed -e 's!nfs://!nfs_!'`
-    MOUNTPATH=`echo $DIRNAME|sed -e 's!nfs_!!'|sed -e 's!/!:/!'`
+    DIRNAME=$(echo $MOUNTURI|sed -e 's!nfs://!nfs_!')
+    MOUNTPATH=$(echo $DIRNAME|sed -e 's!nfs_!!'|sed -e 's!/!:/!')
     if mount|grep $MOUNTPATH > /dev/null; then
         exit 0;
     fi
@@ -124,64 +123,54 @@ elif [ "bridgeprereq" = "$1" ]; then
     modprobe bridge
 
     NETDESC="$2"
-    # get the port for installation
-    if [ -n "$INSTALLNIC" ]; then
-        INSPORT=$INSTALLNIC
-    elif [ -n "$PRIMARYNIC" ]; then
-        INSPORT=$PRIMARYNIC
-    fi
 
-    if [ -z "$INSPORT" ] || [[ "$INSPORT" =~ ^(mac|MAC)$ ]]; then
-        if [ -n "$MACADDRESS" ] ; then   
-            INSPORT=$MACADDRESS;
-        else
-            echo "should configure mac in $NODE definition."
-            exit 1
-        fi
-    fi
-
-    if [[ "$INSPORT"  =~ ^([0-9a-fA-F]{2}:){5}[0-9a-fA-F]{2}$ ]] ; then
-        INSPORT=`ip -oneline link show|grep -i ether|grep -i $INSPORT |awk -F ':' '{print $2}'|grep -o "[^ ]\+\( \+[^ ]\+\)*"`
-    fi
-
-    if [ -z "$NETDESC" ]; then
-        if [ -n "$INSPORT" ]; then
-          NETDESC=$INSPORT:default
-        else
-            echo "Incorrect usage"
-            exit 1
-        fi
-    fi
     if echo "$NETDESC"|grep ':'> /dev/null; then
-        PORTS=`echo "$NETDESC"|cut -d: -f 1`
-        BNAME=`echo "$NETDESC"|cut -d: -f 2`
+        PORTS=$(echo "$NETDESC"|cut -d: -f 1)
+        BNAME=$(echo "$NETDESC"|cut -d: -f 2)
     else 
-        if [ -n "$INSTALLNIC" ]; then
-            PORTS=$INSPORT
+        if [ -n "$NETDESC" ]; then
+            BNAME=$NETDESC
+        else
+            BNAME=default
         fi
-        BNAME=$NETDESC
+
+        # get the port for installation
+        if [ -n "$INSTALLNIC" ]; then
+            PORTS=$INSTALLNIC
+        elif [ -n "$PRIMARYNIC" ]; then
+            PORTS=$PRIMARYNIC
+	else
+            PORTS=$(get_def_interface)
+        fi
+
+        if [ -z "$PORTS" ] || [[ "$PORTS" =~ ^(mac|MAC)$ ]]; then
+            if [ -n "$MACADDRESS" ] ; then   
+                PORTS=$(ip -oneline link show|grep -i ether|grep -i $MACADDRESS |awk -F ':' '{print $2}'|grep -o "[^ ]\+\( \+[^ ]\+\)*")
+            else
+                echo "should configure mac in $NODE definition."
+                exit 1
+            fi
+        fi
+
     fi
 
     # To check whether the brctl have been installed
-    if ! which brctl > /dev/null; then 
+    if ! which brctl &> /dev/null; then 
         echo "No bridge-utils installed, pls install it first"
         exit 1
     fi 
 
-    if brctl showstp "$BNAME" > /dev/null; then
-        echo "$BNAME"
+    if brctl showstp "$BNAME" &> /dev/null; then
+        echo "$BNAME already exists"
         exit 0
     fi
-    #Still here, that means we must build a bridge
-    if [ -z "$PORTS" ]; then #No ports specified, default to whatever looks up
-        PORTS=$(get_def_interface)
-    fi
+
     if [ -z "$PORTS" ]; then #This has been checked many times before in theory, check again just in case
         exit 1
     fi
      
     #TO check whether the NIC had been attached to another bridge
-    bridgename=`brctl show |grep $PORTS`
+    bridgename=$(brctl show |grep $PORTS)
     if [ ! -z "$bridgename" ]; then
         echo "Device $PORTS is already a member of another bridge"
         exit 1
@@ -195,15 +184,15 @@ elif [ "bridgeprereq" = "$1" ]; then
     if echo "$PORTS"|grep '&'; then #we have bonding... fun to be had
     #To be slack, going to just support one bond for now..
         modprobe bonding miimon=100 mode=4
-        PORTS=`echo $PORTS |sed -e 's/&/ /'`
+        PORTS="${PORTS//&/ }"
         ip link set bond0 up
         for p in $PORTS; do
             #TODO: we are only going to manage the default
             #route for now
-            saveroutes=`ip route | grep default| grep "dev $p"|grep via|sed -e 's/dev .*//'`
+            saveroutes=$(ip route | grep default| grep "dev $p"|grep via|sed -e 's/dev .*//')
             OIFS=$IFS
             IFS=$'\n'
-            saveip=`ip addr show dev $p scope global|grep inet|grep -v dynamic|sed -e 's/inet.//'|sed -e 's/[^ ]*$//'`
+            saveip=$(ip addr show dev $p scope global|grep inet|grep -v dynamic|sed -e 's/inet.//'|sed -e 's/[^ ]*$//')
             if [ ! -z "$saveip" ]; then
                 for line in $saveip; do 
                     ip addr add dev bond0 $line
@@ -235,16 +224,12 @@ elif [ "bridgeprereq" = "$1" ]; then
     brctl addbr $BNAME
     brctl setfd $BNAME 0 #fast forwarding
     ip link set $BNAME up
-    saveroutes=`ip route | grep default| grep "dev $PORTS"|grep via|sed -e 's/dev .*//'`
-    OIFS=$IFS
-    IFS=$'\n'
-    saveip=`ip addr show dev $PORTS scope global|grep inet|sed -e 's/inet.//'|sed -e 's/[^ ]*$//'`
+    saveroutes="$(ip route | grep default| grep "dev $PORTS"|grep via|sed -e 's/dev .*//')"
+    saveip="$(ip -4 -o addr show dev $PORTS scope global | sed 's/.*inet //'| sed 's/\( global \).*/\1/')"
     if [ ! -z "$saveip" ]; then
-        for line in $saveip; do 
-            IFS=$OIFS
-            newline=`echo $line|sed 's/dynamic//g'`
-            ip addr add dev $BNAME $newline
-        done
+        while read line; do 
+            ip addr add dev $BNAME ${line//dynamic}
+        done <<<"$saveip"
     else
         if [ ! -z "$3" ]; then
             ip addr add dev $BNAME $3 
@@ -252,16 +237,10 @@ elif [ "bridgeprereq" = "$1" ]; then
     fi
     brctl addif $BNAME $PORTS
     if [ ! -z "$saveip" ]; then
-        OIFS=$IFS
-        IFS=$'\n'
-        for line in $saveip; do 
-            IFS=$OIFS
-           newline=`echo $line|sed 's/dynamic//g'`
-            ip addr del dev $PORTS $newline
-        done
-       IFS=$OIFS
+        while read line; do 
+            ip addr del dev $PORTS ${line//dynamic}
+        done <<<"$saveip"
     fi
-    IFS=$OIFS
     if [ ! -z "$saveroutes" ]; then
         ip route add $saveroutes
     fi
@@ -284,19 +263,19 @@ elif [ "bridgeprereq" = "$1" ]; then
     
      #write into the network configuration file
     if [[ $isSLES -eq 1 ]]; then
-        cat >$nwdir/ifcfg-$PORTS <<EOF
+        { cat <<EOF
 DEVICE='$PORTS'
 ONBOOT='yes'
 BRIDGE='$BNAME'
 EOF
-        mac=`ip addr show dev $PORTS scope global|grep link|sed -e 's/link\/ether//'|sed -e 's/brd.*$//'|sed -e 's/[ ]*//'`
+        mac=$(ip addr show dev $PORTS scope global|grep link|sed -e 's/link\/ether//'|sed -e 's/brd.*$//'|sed -e 's/[ ]*//')
         if [ ! -z "$mac" ]; then
-            echo "HWADDR='$mac'" >> $nwdir/ifcfg-$PORTS
+            echo "HWADDR='$mac'"
         fi
         if [ ! -z "$vlan" ]; then
-            echo "VLAN='yes'" >> $nwdir/ifcfg-$PORTS
-        fi
-        cat >$nwdir/ifcfg-$BNAME <<EOF      
+            echo "VLAN='yes'"
+        fi; } >"$nwdir/ifcfg-$PORTS"
+        { cat <<EOF      
 DEVICE='$BNAME'
 TYPE='Bridge'
 ONBOOT='yes'
@@ -304,13 +283,13 @@ PEERDNS='yes'
 DELAY='0'
 EOF
         if [ ! -z "$3" ]; then 
-            echo "IPADDR='$3'" >> $nwdir/ifcfg-$BNAME 
+            echo "IPADDR='$3'"
             if [ ! -z "$4" ]; then
-                echo "NETMASK='$4'" >> $nwdir/ifcfg-$BNAME
+                echo "NETMASK='$4'"
             fi
         else
-            echo "BOOTPROTO=dhcp" >> $nwdir/ifcfg-$BNAME
-        fi
+            echo "BOOTPROTO=dhcp"
+        fi; } >$nwdir/ifcfg-$BNAME
     elif [ $isDebian ];then
         #ubuntu/debian
         echo "auto $PORTS" >$nwdir/$PORTS
@@ -320,46 +299,48 @@ EOF
             echo "  vlan-raw-device $PORTORG"
         fi
 
-        echo "auto $BNAME" > $nwdir/$BNAME
+        { echo "auto $BNAME"
         if [ ! -z "$3" ];then
-            echo "iface $BNAME inet static" >> $nwdir/$BNAME
-            echo "  address $3" >> $nwdir/$BNAME
+            echo "iface $BNAME inet static"
+            echo "  address $3"
             if [ ! -z "$4" ];then
-                echo "  netmask $4" >> $nwdir/$BNAME
+                echo "  netmask $4"
             else
-                echo "  netmask 255.255.255.0" >> $nwdir/$BNAME
+                echo "  netmask 255.255.255.0"
             fi
         else
-            my_subnet=`ip addr show dev $BNAME scope global|grep inet|grep -v dynamic|sed -e 's/inet.//'| awk '{print $1}'`
+            my_subnet=$(ip -4 -o addr show dev "$BNAME" scope global | awk '!/dynamic/{print $4}' )
             if [ ! -z "$my_subnet" ]; then
-                bridge_ip=`echo "$my_subnet"|cut -d\/ -f 1`
-                bridge_mask=`echo "$my_subnet"|cut -d\/ -f 2`
-                bridge_mask=`v4prefix2mask $bridge_mask`
-                echo "iface $BNAME inet static" >> $nwdir/$BNAME
-                echo "  address $bridge_ip" >> $nwdir/$BNAME 
-                echo "  netmask $bridge_mask" >> $nwdir/$BNAME
+                bridge_ip="${my_subnet//\/*}"
+                bridge_mask="${my_subnet##*\/}"
+                bridge_mask=$(v4prefix2mask "$bridge_mask")
+                echo "iface $BNAME inet static"
+                echo "  address $bridge_ip"
+                echo "  netmask $bridge_mask";
             else 
-                echo "iface $BNAME inet dhcp" >> $nwdir/$BNAME
+                echo "iface $BNAME inet dhcp"
             fi
         fi
-        echo "  bridge_ports $PORTS" >> $nwdir/$BNAME
-        echo "  bridge_stp off" >> $nwdir/$BNAME
-        echo "  bridge_fd 0" >> $nwdir/$BNAME
-        echo "  bridge_maxwait 0" >> $nwdir/$BNAME
+        echo "  bridge_ports $PORTS"
+        echo "  bridge_stp off"
+        echo "  bridge_fd 0"
+        echo "  bridge_maxwait 0"; } > "$nwdir/$BNAME"
     else
-        cat >$nwdir/ifcfg-$PORTS <<EOF
+        # Migrate some PORTS configuration to Bridge:
+        ATTRS="$(egrep '^BOOTPROTO|^IPADDR|^NETMASK|^NETWORK|^GATEWAY' $nwdir/ifcfg-$PORTS)"
+        { cat <<EOF
 DEVICE=$PORTS
 ONBOOT=yes
 BRIDGE=$BNAME
 EOF
-        mac=`ip addr show dev $PORTS scope global|grep link|sed -e 's/link\/ether//'|sed -e 's/brd.*$//'|sed -e 's/[ ]*//'`
+        mac=$(ip -0 -o addr show dev "$PORTS" scope global|awk '{print $(NF-2)}')
         if [ ! -z "$mac" ]; then
-            echo "HWADDR=$mac" >> $nwdir/ifcfg-$PORTS
+            echo "HWADDR=$mac"
         fi
         if [ ! -z "$vlan" ]; then
-            echo "VLAN=yes" >> $nwdir/ifcfg-$PORTS
-        fi
-        cat >$nwdir/ifcfg-$BNAME <<EOF      
+            echo "VLAN=yes"
+        fi; } >"$nwdir/ifcfg-$PORTS"
+        { cat <<EOF      
 DEVICE=$BNAME
 TYPE=Bridge
 ONBOOT=yes
@@ -367,16 +348,14 @@ PEERDNS=yes
 DELAY=0
 EOF
         if [ ! -z "$3" ]; then 
-            echo "IPADDR=$3" >> $nwdir/ifcfg-$BNAME 
+            echo "IPADDR=$3"
             if [ ! -z "$4" ]; then
-                echo "NETMASK=$4" >> $nwdir/ifcfg-$BNAME
+                echo "NETMASK=$4"
             fi
         else
-            echo "BOOTPROTO=dhcp" >> $nwdir/ifcfg-$BNAME
-        fi
+            echo "$ATTRS"
+        fi ; }  > "$nwdir/ifcfg-$BNAME"
     fi 
  
-    ifdown $BNAME;ifup $BNAME
+    ifdown "$BNAME"; ifup "$BNAME"
 fi #END bridge config.
-
-