gorethrasher

Using crontab and a simple shell script we can configure Linux to take screenshots at defined intervals.

Create a file called screen.sh and place it in /home/<username>/bin and give it execute permissions

#!/bin/bash
cd /home/laszlo/screenshots
DISPLAY=:0.0 import -window root screen` date|awk 'OFS="."{print $2,$3,$6,$4}'`.png

Modify the cd command to suit your environment

date|awk… appends the date and time to the filename (so we don’t overwrite the previous ones)

Now we just need to use crontab to execute the script at regular intervals

~>crontab -e

this brings up the editor, insert a similar line and save the file (Press Esc and then SHIFT ZZ to save and exit VI)

0,30 * * * * /home/laszlo/bin/screen.sh

Cron will execute the script /home/laszlo/bin/screen.sh on minute 0 and 30 each hour every day

Notice the comma between the 0 and the 30. That is to separate the values of the first field.

for more detail on crontab and its paramaters see crontab

One thing I wanted to get working is to ignore when the computer was idle. This program should give you the idle time of the machine, you can use the output to determine whether to take a screenshot - getting idle time in Linux

#!/bin/bash
cd /home/laszlo/screenshots

idle=$(/home/laszlo/bin/idle)

if [ $idle -lt 60000 ]; then
DISPLAY=:0.0 import -window root screen` date|awk 'OFS="."{print $2,$3,$6,$4}'`.png
else echo "User idle for :" $idle
fi

You can also edit the crontab entry to not capture at night when you are sleeping.

Tags: automation, Linux, screenshot, scripting, shell

This entry was posted on Thursday, January 22nd, 2009 at 9:38 am and is filed under Linux. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.