Scripting An Image's History?

ridertech · 12-13-2004, 02:19 PM

I'm trying to track a web cam by using cron & wget, but I'm still very new to scripting...

Basically, I'd like to grab the cam's image every 15 minutes and keep only the last twenty images. In order to save storage space, I'd like to use the same twenty file names and just overwrite the oldest file.

I'm currently using the following crontab command to wget the images every 15 minutes...

0,15,30,45 * * * * root /usr/bin/webcam.sh >> /dev/null 2>&1

My scripting confusion begins with the file naming and only gets worse when I think of how to overwrite the oldest image.

Any advice would be of great help.

acid_kewpie · 12-13-2004, 02:31 PM

you can get the oldest file in a directory like this:

Code:

/bin/ls -t | tail -n 1

among dozens of other ways, that's what springs to mind for me.

in practise i'd probably take a different approach and use a datestamp to implictly overwrite it. if you write to a file called

Code:

image`date +%I%M`.png

then that will include a 12 hour clock in the filename. so every 12 hours that file will be over written. I presume 20 is actually an arbitrary figure?