sed -Ei '/^[[:space:]]*#?[[:space:]]*precedence[[:space:]]+::ffff:0:0\/96[[:space:]]+100\b.*?$/ {s/.+100\b([[:space:]]*#.*)?$/precedence ::ffff:0:0\/96 100\1/; :a;n;b a}; /^[[:space:]]*precedence[[:space:]]+::ffff:0:0\/96[[:space:]]+[0-9]+.*$/ {s/^.*precedence.+::ffff:0:0\/96[^0-9]+([0-9]+).*$/precedence ::ffff:0:0\/96 100\t#原值为 \1/; :a;n;ba;}; $aprecedence ::ffff:0:0\/96 100' /etc/gai.conf
来源：https://www.nodeseek.com/post-73797-1
