How to install lessc and node

Overview

The 'lessc' program is actually a javascript file which is run via node, so you'll first need to install node using this related community post, or manually using our home-install guide.

Then, once that's done, grab Less CSS.

The installation procedure for lessc is similar to the home-install guide, except that it seems that less CSS doesn't use the "./configure" step. After installing node, you should be able to just run "make" or use bin/lessc directly.

Guide

Install node.js and then lessc.

Recently node is much easier to install than in the past, so we can just install it as any other normal source-code application:

# create ~/src, where we keep all source code
mkdir -p $HOME/src

###########################################################
# node 0.8.9
###########################################################
cd $HOME/src
wget 'http://nodejs.org/dist/v0.8.9/node-v0.8.9.tar.gz'
tar -xzf node-v0.8.9.tar.gz
cd node-v0.8.9
./configure --prefix=$HOME
make                         # build it
make install                 # install it

# clear the shell hash so we know we're using the correct path
hash -r
which node    # should be ~/bin/node

###########################################################
# Less CSS
###########################################################
cd $HOME/src
git clone 'https://github.com/cloudhead/less.js.git'
cd less.js
make                         # build it
cp -r ./bin/* $HOME/bin/     # install binaries
cp -r ./lib/* $HOME/lib/     # install libraries

# clear the shell hash so we know we're using the correct path
hash -r
which lessc        # should be ~/bin/lessc

Discussion

Installing software has three parts. First, you configure it, which means changing and setting the compile-time options. Many pieces of software can be compiled in different ways, with different internal paths, and with certain options like multithreading turned on or off. The ./configure stage does this, and when installing node, we used ./configure --prefix=$HOME. Setting the --prefix is setting a compile-time option which defines the internal paths hard-coded into the binary itself. Running the ./configure step generates a Makefile.

Some programs are so simple that don't have any compile-time options at all, or they have just a handful which can be manually set inside of the Makefile itself. These programs don't have a ./configure step. You can recognize them because they don't have a configure script inside of the source directory, but directly have a Makefile instead. lessc was one such example.

The next step is to compile the software. This is what the make command does. When you type make, it compiles the software, putting all of the compiled programs into subdirectories of your current working directory. The make command uses the Makefile as its recipe for how to do this.

The final step is to install the software. Installation usually means nothing more than copy-pasting those binaries into their new permanent locations. In the first example here where we installed node, the make install step knows about the --prefix we set during the configure stage, so just typing make install copies the compiled files to where they can be run. In our case, that puts node inside of $HOME/bin. But you should also be aware that it put a library inside of your $HOME/lib directory too.

The lessc program didn't have any such make install mode. You can try typing make install to see if it works - it doesn't, in this case, so we just do a manual install by copying the binaries and libraries to $HOME/bin and $HOME/lib respectively. To "uninstall" a program, delete the files you installed.

There is a lot more to installation than this. For example, sometimes some software needs to compile in dependencies for other software, which is where the CPPFLAGS, LDFLAGS come into play. And sometimes programs need to have your $HOME/lib on the library path in order to function when you try to execute them -- and that's what LD_LIBRARY_PATH is for. These environment variables are covered briefly in our documentation.

If you're looking for in-depth knowledge and examples about compiling and installing software on linux, the book How Linux Works by Brian Ward is the best material on the subject that I've seen, so I'd strongly recommend it as the best place to start to really understand what's going on.

Hope that helps!