Clean up after script ends (e.g. on ssh timeout)

clean-up-after-cmd-exit.sh

#!/bin/bash
# Clean up after script ends (e.g. on ssh timeout)

TIMEOUT=3
HEARTBEAT=$(( TIMEOUT - 2 ))
TIMESTAMP_FILE=$( mktemp )

date +%s > ${TIMESTAMP_FILE}

nohup bash -c "
    while sleep ${TIMEOUT}
    do
        TIMESTAMP=\$( cat ${TIMESTAMP_FILE} )
        NOW=\$( date +%s )
        if (( NOW - TIMESTAMP > ${TIMEOUT} ))
        then
            notify-send --hint=int:transient:1 -- OHAI
            break
        fi
    done
" 2>/dev/null &

echo 'Kill me with ^C after some while'

while sleep ${HEARTBEAT}
do
    NOW=$( date +%s )
    echo $NOW > ${TIMESTAMP_FILE}
done