What is the Best Way to Perform Timestamp Comparison in Bash
By far the easiest is to store time stamps as modification times of dummy files. GNU touch and date commands can set/get these times and perform date calculations. Bash has tests to check whether a file is newer than (-nt) or older than (-ot) another.
For example, to only send a notification if the last notification was more than an hour ago:
touch -d '-1 hour' limitif [ limit -nt last_notification ]; then #send notification... touch last_notificationfi
Use the date command to convert the two times into a standard format, and subtract them. You'll probably want to store the previous execution time in a dotfile then do something like:
last = cat /tmp/.lastruncurr = date '+%s'diff = $(($curr - $last))if [ $diff -gt 3600 ]; then # ...fiecho "$curr" >/tmp/.lastrun(Thanks, Steve.)