Is there a way to find out, when a recoll-index was last updated?
Since it stores the indexes under
$HOME/.recoll/xapiandb I would simply find the newest file under there:
find ~/.recoll/xapiandb -type f -printf '%T@\t%T+\n' \ | sort -nr | head -n 1 | cut -f2
This prints out all files with their epoch time and human-readable time, then sorts it so the newest is at the top and then prints only the human readable time of the first one. Adjust the
printf format according to what output you need.