Hello.
Maybe there is an easier way, but you could try putting your "variable" into a file.
An example: I turn my computer on and off as and when I need it, maybe several times a day.
I use ntpdate to sync my local time. I do not want to do this every boot-time, just once a day. I also wanted to play with
cron. So cron calls this script once an hour:
Code:
#!/bin/bash
# No need to check the time more than once a day,
# no matter how often this script is called by cron
NOW=`date | cut -b 1-10`
LAST=`cat /etc/.lasttimecheck`
if [ "$NOW" != "$LAST" ]; then
echo $NOW > /etc/.lasttimecheck
/usr/sbin/ntpdate time-server.kindlypeople.com
fi
My "variable" is the date the time was last checked. It is held in the file
.lasttimecheck. If that is not today, the time is checked, and the file is updated.
Hope this helps.