MacのネットワークにそれぞれにDNS設定するのだるいし、都度調べるのもだるいのでスクリプト

README.md

dns-manager.sh

Commands

Get DNS servers

dns-manager.sh get -s Wi-Fi

Set DNS servers

dns-manager.sh set -s Wi-Fi -d cloudflare

dns-manager.sh

#!/usr/bin/env bash

# Macでないなら実行しない
if [ "$(uname -s)" != "Darwin" ]; then
    echo "This computer isn't Darwin!"
    exit 1
fi

set -o errexit
set -o pipefail

setDnsServers() {
    local NETWORK_SERVICE_NAME=""
    local DNS_SERVER_SET=""
    local DNS_SERVERS=""

    while [ "$1" != "" ]
    do
        case "$1" in
            --network-service|-s)
                NETWORK_SERVICE_NAME="$2"
                shift
                shift
                ;;
            --dns|-d)
                DNS_SERVER_SET="$2"
                shift
                shift
                ;;
            --verbose|-v)
                set -o xtrace
                shift
                ;;
            *)
                echo "Unknown option: $1" >&2
                exit 1
                ;;
        esac
    done

    if [ -z "$NETWORK_SERVICE_NAME" ]; then
        echo "Required --network-service" >&2
        exit 1
    fi

    case "$DNS_SERVER_SET" in
        cloudflare)
            DNS_SERVERS="1.1.1.1 1.0.0.1 2606:4700:4700::1111 2606:4700:4700::1001"
            ;;
        google)
            DNS_SERVERS="8.8.8.8 8.8.4.4 2001:4860:4860::8888 2001:4860:4860::8844"
            ;;
        "")
            DNS_SERVERS="Empty"
            ;;
        *)
            DNS_SERVERS="$DNS_SERVER_SET"
            ;;
    esac

    networksetup -setdnsservers $NETWORK_SERVICE_NAME $DNS_SERVERS
}

getDnsServers() {
    local NETWORK_SERVICE_NAME=""

    while [ "$1" != "" ]
    do
        case "$1" in
            --network-service|-s)
                NETWORK_SERVICE_NAME="$2"
                shift
                shift
                ;;
            --verbose|-v)
                set -o xtrace
                shift
                ;;
            *)
                echo "Unknown option: $1" >&2
                exit 1
                ;;
        esac
    done

    if [ -z "$NETWORK_SERVICE_NAME" ]; then
        echo "Required --network-service" >&2
        exit 1
    fi

    networksetup -getdnsservers $NETWORK_SERVICE_NAME
}

case "$1" in
    set)
        shift
        setDnsServers $@
        ;;
    get)
        shift
        getDnsServers $@
        ;;
    *)
        echo "Unknown subcommand: $1" >&2
        exit 1
        ;;
esac