case "$-" in
    *i*)
        interactive=1
        ;;
    *)
        not_interactive=1
        ;;
esac

if [ -z "$PS1" ]; then
    not_interactive=1
else
    interactive=1
fi

if [ -t 0 ]; then
    interactive=1
else
    non_interactive=1
fi

CRONPID=$(ps ho %p -C cron)
PPID=$(ps ho %P -p $$)
if [ $CRONPID -eq $PPID ] ; then echo Cron is our parent. ; fi

PPID=$$   # start from current PID
CRON_IS_PARENT=0
CRONPID=$(ps ho %p -C cron)
while [ $CRON_IS_PARENT -ne 1 ] && [ $PPID -ne 1 ] ; do
  PPID=$(ps ho %P -p $PPID)
  [ $CRONPID -eq $PPID ] && CRON_IS_PARENT=1
done

# start from current PID
MYPID=$$
CRON_IS_PARENT=0
# this might return a list of multiple PIDs
CRONPIDS=$(ps ho %p -C crond)

CPID=$MYPID
while [ $CRON_IS_PARENT -ne 1 ] && [ $CPID -ne 1 ] ; do
        CPID_STR=$(ps ho %P -p $CPID)
        # the ParentPID came up as a string with leading spaces
        # this will convert it to int
        CPID=$(($CPID_STR))
        # now loop the CRON PIDs and compare them with the CPID
        for CRONPID in $CRONPIDS ; do
                [ $CRONPID -eq $CPID ] && CRON_IS_PARENT=1
                # we could leave earlier but it's okay like that too
        done
done

# now do whatever you want with the information
if [ "$CRON_IS_PARENT" == "1" ]; then
        CRON_CALL="Y"
else
        CRON_CALL="N"
fi

echo "CRON Call: ${CRON_CALL}"

if [ "Z$(ps o comm="" -p $(ps o ppid="" -p $$))" == "Zcron" -o
     "Z$(ps o comm="" -p $(ps o ppid="" -p $(ps o ppid="" -p $$)))" == "Zcron" ]
then
    echo "Called from cron"
else
    echo "Not called from cron"
fi

PPPID=`ps h -o ppid= $PPID`

P_COMMAND=`ps h -o %c $PPPID`

if [ "$P_COMMAND" == "cron" ]; then
  RUNNING_FROM_CRON=1
fi

if [ "$RUNNING_FROM_CRON" == "1" ]; then
  ## do something when running from cron
else
  ## do something when running from shell
fi