bash

#!/bin/bash

MINSIZE=1000000

while :
do
    SIZE=$(du -sb "server_log.txt" | awk '{ print $1 }')
    if (($SIZE>$MINSIZE))
    then
        NOW=$(date +"%Y-%m-%d-%H-%M")
        cat server_log.txt > server_log_$NOW.txt
        sleep 30
        cat /dev/null > server_log.txt
        sleep 10
    fi
    if [ $(pidof veryuniqueprocess) ]
    then
        sleep 10
    else
        screen -dmS `whoami` ./veryuniqueprocess
        sleep 60
    fi
done