SED delete lines between two pattern matches

Question

I am trying to replace lines between two pattern/string matches using SED see below. I need to delete lines below interface GigabitEthernet0/3 up to inter

Answer 1

The basic answer seems simple to me:

sed -e "/interface GigabitEthernet0\/3/p" \
    -e "/interface GigabitEthernet0\/4/p" \
    -e "/interface GigabitEthernet0\/3/,/interface GigabitEthernet0\/4/d" "$@"

Print lines matching 'interface GigabitEthernet0/3', and lines containing 'interface GigabitEthernet0/4'; delete the lines between and including the two.

The only possible issue is that if there is 'interface GigabitEthernet0/4' and no preceding 'interface GigabitEthernet0/3', then that line will be doubled up. If that's an actual problem, then go for a more complex script:

sed -e "/interface GigabitEthernet0\/3/,/interface GigabitEthernet0\/4/{
        /interface GigabitEthernet0\/3/p
        /interface GigabitEthernet0\/4/p
        d
        }" "$@"

If you're adamant it must be one line, use semicolons, but the result is illegible.