[eschwartz]

Originally Posted by Geremia

Actually, this isn't true. For some reason, the cronjob exits with error 127. See this unsolved StackOverflow question.

And Kovid fixed that. See here: Official calibre PPA? where we discussed updating via a script using that check.

This thread also has a nice elegant way of checking if there is an update available -- Kovid helped us thrash it out.

Here it is:

#!/bin/bash

calibre-debug -c "import urllib as u; from calibre.constants import numeric_version; raise SystemExit(int(numeric_version  < (tuple(map(int, u.urlopen('http://calibre-ebook.com/downloads/latest_version').read().split('.'))))))"

UP_TO_DATE=$?

if [ $UP_TO_DATE = 0 ]; then
        echo "Calibre is up-to-date"
else
        killall calibre calibre-server
        sudo python -c "import sys; py3 = sys.version_info[0] > 2; u = __import__('urllib.request' if py3 else 'urllib', fromlist=1); exec(u.urlopen('http://status.calibre-ebook.com/linux_installer').read()); main(install_dir='/opt')"
fi