I have a folder that contains versions of my application, each time I upload a new version a new sub-folder is created for it, the sub-folder name is the current timestamp, here
Your directory names are sorted in chronological order, which makes this easy. The list of directories in chronological order is just *
, or [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]
to be more precise. So you want to delete all but the last 10 of them.
set [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]/
while [ $# -gt 10 ]; do
rm -rf "$1"
shift
fi
(While there are more than 10 directories left, delete the oldest one.)