WoW API (https://develop.battle.net/) client code in GoLang
Create a client on https://develop.battle.net/access/clients
and set OAUTH_CID and OAUTH_SEC in your environment, the program will also try to use OAUTH_{CID|SEC}_{REGION} if present. Use -authregion eu to use eu battle.net oauth client instead of us.
Then go run realmlist.go -status for US server status list and go run realmlist.go -region eu for EU region list
By default it pretty prints the whole Json structure returned (which is more complete when using the -status realm status api option) but you can use -lua to just get the realm id to names as LUA code suitable for WoW Addons (use https://github.com/mooreatv/MoLib if you just want to use that data)
go run realmlist.go -lua -region eu > Realms_eu.lua
go run realmlist.go -lua -region us > Realms_us.luaThe resulting files and utility LUA functions for Wow addons are available in as part of https://github.com/mooreatv/MoLib
Add -loglevel verbose or -loglevel debug to see more details during the execution.