Mine

cmd1= echo cmd1
cmd2= echo cmd2
cmd3= echo cmd3
cmd4= XXecho cmd4
cmd5= echo cmd5
cmd6= echo cmd6
cmd7= echo cmd7
cmd8= echo cmd8
cmd9= echo cmd9
cmd10= echo cmd10
undo_cmd1= echo undo_cmd1
undo_cmd2= echo undo_cmd2
undo_cmd3= echo undo_cmd3
undo_cmd4= echo undo_cmd4
undo_cmd5= echo undo_cmd5
undo_cmd6= echo undo_cmd6
undo_cmd7= echo undo_cmd7
undo_cmd8= echo undo_cmd8
undo_cmd9= echo undo_cmd9
undo_cmd10= echo undo_cmd10



command[1]='cmd1'
undo[1]='undo_cmd1'

command[2]='cmd2'
undo[2]='undo_cmd2'

command[3]='cmd3'
undo[3]='undo_cmd3'

command[4]='cmd4'
undo[4]='undo_cmd4'

command[5]='cmd5'
undo[5]='undo_cmd5'

command[6]='cmd6'
undo[6]='undo_cmd6'

command[7]='cmd7'
undo[7]='undo_cmd7'

command[8]='cmd8'
undo[8]='undo_cmd8'

command[9]='cmd9'
undo[9]='undo_cmd9'

command[10]='cmd10'
undo[10]='undo_cmd10'

exit_status=$?
count=0
countup=`expr $count + 1`
countdown=`expr $count - 1`

#while [ $exit_status -eq 0 -o "$count" -le 10 ]
while true
do
        if [ $exit_status -eq 0 -a "$count" -le 10 ]
        then
        command $count
        echo $exit_status
        count=$(expr $count + 1)
        fi

        if [ $exit_status -eq 1 -a "$count" -le 10 ]
        then
        command $count
        echo $exit_status
        count=$(expr $count - 1)
        fi

done