ImageMagick's "import" command line program failing to take a screenshot from CRON script

Question

Hello I wrote a simple command line script which is suppose to take my screenshot every 5 minutes.

(using ImageMagick's "import" program)

here is the script (shottr.sh):

#!/bin/sh

PTH="/home/username/images"
NM=`date +%j`_`date +"%F %k:%M"`

/usr/bin/import -window root -resize 1024 "$PTH/$NM.png" &
echo "Screenshot" | festival --tts &

this is working fine if I execute by hand i.e:

# ./shottr.sh

or

#sh shottr.sh

the cron is set like this:

*/5 * * * * /bin/sh /home/username/scripts/shottr.sh

the script itself is being executed (I hear a voice saying: "Screenshot") but the actual screenshot is not taken.

P.S: Be assured that it is NOT permission issue (I placed a simple "touch" invocation and file was created)

may be if it's run from cron...it doesn't have a "window" so it can't take a screenshot from nowhere?? If that is the case, then how can I workaround it?

Answer 1

When you're running the script from cron it doesn't have access to your DISPLAY environment variable, which is how it knows what X11 display with which to interact. You may be able to get it to work by adding the following to your script:

# Set display to :0 if it's not already set.
: ${DISPLAY:=:0}
export DISPLAY

This assumes that your DISPLAY is always :0, which is true if you're logging in on the console but not true if you're running X remotely.