Add irule via tmsh without deleting existing irules, and how to re-order

Until F5 incorporates this feature request into the product I wrote two scripts to allow appending an iRule to as well as deleting an iRule from an existing virtual:

!/bin/sh

 f5-irule-add - add iRule to virtual server, preserving existing iRule configuration

 Thomas Brown, CA Technologies - Mon Aug  1 15:21:29 GMT 2016 - initial version


 Parse command line arguments
if [ $ -ne 2 ]; then
   echo "Usage: $0 virtual irule" >&2
   exit 1
fi
virtual=$1
irule_add=$2

 Capture existing iRule configuration
tmsh list ltm virtual ${virtual} one-line | grep -q " rules { "
if [ $? -eq 1 ]; then
   echo "$0: ${virtual} currently contains no rules; adding new rule"
   irule_current=""
else
   irule_current=`tmsh list ltm virtual ${virtual} one-line | sed -e 's/.* rules { //' -e 's/ }.*//'`

    Check if rule already exists
   exists=0
   for rule in ${irule_current}
   do
      if [ ${rule} == ${irule_add} ]; then
         exists=1
      fi
   done
   if [ ${exists} -eq 1 ]; then
      echo "$0: ${irule_add} already exists in virtual ${virtual}" >&2
      exit 2
   fi
fi

 Modify iRule list
command="tmsh modify ltm virtual ${virtual} rules { ${irule_current} ${irule_add} }"
echo ${command}
exec ${command}
status=$?
if [ ${status} -ne 0 ]; then
   echo "tmsh returned error status ${status}" >&2
   exit ${status}
fi

!/bin/sh

 f5-irule-delete - delete iRule from virtual server, preserving existing iRule configuration

 Thomas Brown, CA Technologies - Mon Aug  1 15:52:03 GMT 2016 - initial version


 Parse command line arguments
if [ $ -ne 2 ]; then
   echo "Usage: $0 virtual irule" >&2
   exit 1
fi
virtual=$1
irule_del=$2

 Capture existing iRule configuration
tmsh list ltm virtual $virtual one-line | grep -q " rules { "
if [ $? -eq 1 ]; then
   echo "$0: ${virtual} currently contains no rules; exiting"
   exit 2
else
   irule_current=`tmsh list ltm virtual ${virtual} one-line | sed -e 's/.* rules { //' -e 's/ }.*//'`

    Check if rule already exists
   exists=0
   for rule in ${irule_current}
   do
      if [ ${rule} == ${irule_del} ]; then
         exists=1
      fi
   done
   if [ ${exists} -eq 0 ]; then
      echo "$0: ${irule_del} does not exist in virtual ${virtual}" >&2
      exit 2
   else
      irule_current=`echo " ${irule_current} " | sed -e "s/ ${irule_del} / /"`
   fi
fi

 Modify iRule list
command="echo tmsh modify ltm virtual ${virtual} rules { ${irule_current} }"
echo ${command}
exec ${command}
status=$?
if [ ${status} -ne 0 ]; then
   echo "tmsh returned error status ${status}" >&2
   exit ${status}
fi