#!/bin/bash

curl -Ss 'http://ftp.gnome.org/pub/gnome/sources/gnome-icon-theme-symbolic/' | \
  tr '<>' '\n' | \
  sed '
    s,^\([0-9.]\+\)/$,\1,
    t
    d
  ' | \
  sort -Vr | \
  while read -r ver; do
    curl -Ss "http://ftp.gnome.org/pub/gnome/sources/gnome-icon-theme-symbolic/${ver}/" | \
      tr '"' '\n' | \
      grep -m1 '^gnome-icon-theme-symbolic-[0-9.]\+\.tar\.xz$' && \
      break
  done | \
  sed '
    s/^gnome-icon-theme-symbolic-\([0-9.]\+\)\.tar\.xz$/\1/
  '