Simplify empty check for /etc/resolv.conf

Shorten regular expression for grep command which matches empty lines
and lines with comments.

Signed-off-by: Benjamin Drung <benjamin.drung@cloud.ionos.com>

diff --git a/components/9990-main.sh b/components/9990-main.sh
index 4ea8ee1..7e385f5 100755 (executable)
--- a/components/9990-main.sh
+++ b/components/9990-main.sh
@@ -171,7 +171,7 @@ Live ()
        else
                DNSFILE="${rootmnt}/etc/resolv.conf"
        fi
-       if [ -f /etc/resolv.conf ] && ! grep -E -q -v '^[[:space:]]*#|^[[:space:]]*$' "${DNSFILE}"
+       if [ -f /etc/resolv.conf ] && ! grep -E -q -v '^[[:space:]]*(#|$)' "${DNSFILE}"
        then
                log_begin_msg "Copying /etc/resolv.conf to ${DNSFILE}"
                cp -v /etc/resolv.conf "${DNSFILE}"