Check if variable is numeric or string

#! /bin/ksh
# set -x
# This menu reads a control file to gather the latest list of agents
#  then checks to see if the agent is running as a process.
# When displaying the agent list on the screen, it's status is included
#  (running or stopped).
# Until the user exits the program, each time they press the enter key
#  (whether they entered a reply or not) the program loops and provides
#  a current status of the agent processes.
# They choose which agent they'd like to start from the menu.
# Only agents that are not running will be started regardless of what
#  the user selects.
#

while true
do
clear
  echo "Below are agents and their current statuses."
  echo
  echo
  echo "Press ENTER to refresh screen or choose an agent below to stop it. "
  echo "Note: Logging will stay enabled for the tables in the agent. "
  echo
  AGENTCTL=/iway/cdcagent/config/agent.ctl
  proc_count=0
  cat $AGENTCTL |  while read LINE
  do
  case $LINE in
    \#* )   ;;  #comment line-Ignore
       *) PROCESS=`ps -ef | grep iwaycdcagent | grep $LINE | awk '{print $2}'`
          proc_count=`expr $proc_count + 1`
          item_list=`echo $item_list $LINE`
          if [ "$PROCESS" = "" ] ; then
            echo "$proc_count. $LINE - stopped"
          else
            echo "$proc_count. $LINE - Running"
          fi
  esac

  done

  proc_count=`expr $proc_count + 1`  # this sets the next menu item for ALL
  echo "$proc_count. ALL running agents"

  echo "x. Exit"
  echo
  echo Select an item to stop an agent or $proc_count for ALL Agents.
  echo
  echo $MSG
  echo


  read answer1 answer2

lanswer1=`echo $answer1 | tr '[A-Z]' '[a-z]'`
lanswer2=`echo $answer2 | tr '[A-Z]' '[a-z]'`

if [ "$lanswer1" = "x" ] ; then
  break
fi

if [ "$lanswer2" = "" ] || [ "$lanswer2" = "reset" ] ; then

expr $lanswer1 + 0 > /dev/null 2>&1
if [ $? -eq 0 ] && [ "$lanswer1" != "" ] ; then
   lanswer1=`expr $lanswer1 + 0`
    if [ $lanswer1 -lt $proc_count ] ; then
     startitem=`echo "$item_list" | cut -f"$lanswer1"-"$lanswer1" -d" "`
     PROCESS=`ps -ef | grep iwaycdcagent | grep $startitem | awk '{print $2}'`
     if [ "$PROCESS" = "" ] ; then
#      start command here.
      MSG="$startitem starting...press ENTER to refresh status."
     else
      MSG="$startitem already running."
     fi
    elif [ "$lanswer1" -eq "$proc_count" ] ; then # this to start all loop
      proc_loop=1
      while [ $proc_loop -lt $proc_count ]
      do
       startitem=`echo "$item_list" | cut -f"$proc_loop"-"$proc_loop" -d" "`
       PROCESS=`ps -ef | grep iwaycdcagent | grep $startitem | awk '{print $2}'`
        if [ "$PROCESS" = "" ] ; then
          # start command issued here
     echo "this msg to suppress error since command isnt used yet" > /dev/null
        fi
        proc_loop=`expr $proc_loop + 1`
      done
      MSG="starting all agents...press ENTER to refresh status."
    else
      MSG="...Invalid option. Try again."
    fi
  else
    MSG="...Invalid option. Try again."
  fi

else # answer2 not valid
  MSG="...Invalid option $answer2.  Try again."
fi
done

                                              

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