Scripting needed for newbie

[frans]

Here code that doesn't use at but sleep; it doesn't need external storage of data but runs continuously.
Wat i suggest is to log evrything in the beginning by echoing the variables to the logfile, mainly the Delay to see if you have to adjust the tolerance at another value.
I let you code the different logs you want to make (i can help u) but try first the functioning of the script. You can add lines for monitoring purpose by echoing commands or start the script with the -x parameter like bash -x simple.sh

#!/bin/bash
File1=simple.txt    # The file to check
LogFile=simple.log # The log file
DelayMax=30 # Timeout delay
Tolerance=2 
# BEGIN ##############################
while true
do
    StampNow=$(date +%s)/60    # stamp in minutes
    StampFile=$(date -r "$File1" +%s)/60
    let Delay=$StampNow-$StampFile
    if [ $Delay -gt $DelayMax ]
    then
        echo "$(date) : ERROR : Timeout" >> $LogFile
        # etc.
        exit 1
    elif [ $StampFile -eq $StampOld ]
    then
        sleep $Tolerance minutes # Retry a bit later
    else
        StampOld=$StampFile
        let NewDelay=$StampNow-$StampFile+15+$Tolerance # To synchronize with the updating
        sleep $NewDelay minutes
    fi
done