th command not found in google colab

[Binathi Bingi]

I am trying to run this code from github on google colab.

To execute the code, i have to run the command "th preprocess.lua -config config-preprocess". Whenever I use this command on colab it says, 

File "<ipython-input-12-54cab3b36489>", line 1

th preprocess.lua -config config-preprocess ^ SyntaxError: invalid syntax

I tried installing Lua 5.2 on colab using the instructions in the link http://torch.ch/docs/getting-started.html .I ran the following commands

!git clone https://github.com/torch/distro.git ~/torch --recursive 

cd ~/torch

!./clean.sh

!TORCH_LUA_VERSION=LUA52 ./install.sh

!luarocks install image

When I run the command !luarocks install image. It gives the error

/bin/bash: luarocks: command not found