A very shoddy command thrown together in like 30 minutes used to count the least used textures in a .vmf file. Can be adapted to do other things too if you know what you're doing.
I doubt anyone will find a use for this, but I needed it, so I figured I might as well share it.
Drop vmftexturecounter.lua into your garrysmod/lua/autorun/ folder, and type "CountLeastUsedTextures" in the in-game console. The two arguments are the map (which you must drop into your garrysmod/data/ folder) and the number of textures to list.
Don't care.