Get a list of "server_name" an nginx server knows about (FreeBSD version, using gsed)

show_server_names.sh

#!/bin/bash

sudo nginx -T 2>/dev/null \
  | gsed -r -e 's/[[:space:]]*$//' -e 's/^[[:space:]]*//' -e 's/^#.*$//' -e 's/[[:space:]]*#.*$//' -e '/^$/d' \
  | gsed -e ':a;N;$!ba;s/\([^;\{\}]\)\n/\1 /g' \
  | grep 'server_name[[:space:]]' \
  | grep -v '\$' \
  | grep '\.' \
  | gsed -r -e 's/(\S)[[:space:]]+(\S)/\1\n\2/g' -e 's/;//' \
  | grep -v "^server_name$" \
  | grep -v "^$" \
  | sort \
  | uniq