что значит \!имею в виду?находить .\!-user redis -exec chown redis '{}' +

Question

В образе Redis Docker найти
/usr/local/bin/docker-entrypoint.sh

#!/bin/sh
set -e

# first arg is `-f` or `--some-option`
# or first arg is `something.conf`
if [ "${1#-}" != "$1" ] || [ "${1%.conf}" != "$1" ]; then
        set -- redis-server "$@"
fi

# allow the container to be started with `--user`
if [ "$1" = 'redis-server' -a "$(id -u)" = '0' ]; then
        find . \! -user redis -exec chown redis '{}' +
        exec gosu redis "$0" "$@"
fi

exec "$@"

.\! -user redis -exec chown redis '{}' +
что означает \!?