Wednesday, November 3, 2010

~/bin: apod-set-bg

Astronomy Picture Of the Day shows a new, usually desktop sized, picture every day. apod-set-bg is a shell script to download the daily image and set it as the desktop background. It also downloads the explanation as a separate html file.

Requirements: curl, tidy, xmlstarlet, feh.




URL_CONTENT=`curl $APOD_URL | tidy -q -asxml`

IMG_URL=$APOD_URL`echo "$URL_CONTENT" | xml sel -N html='' -t -v '//html:img/ancestor::html:a/attribute::href' -`

EXPLANATION=`echo "$URL_CONTENT" | xml sel -N html='' -t -c '/html:html/html:body/html:center[2]' -c '/html:html/html:body/html:p' -`

FILE_NAME=`basename "$IMG_URL"`


curl -o "$FILE_PATH" "$IMG_URL" || exit 1

echo "$EXPLANATION" > "$FILE_PATH.html"

ln -sf "$FILE_PATH" "$IMG_DIR/latest.jpg"
ln -sf "$FILE_PATH.html" "$IMG_DIR/latest.html"

feh --bg-fill "$FILE_PATH"

Put the following in your crontab to run daily.

@daily ID=apod DISPLAY=:0.0 ~/bin/apod-set-bg ~/bg/ >/dev/null 2>&1