Setup sass & gulp

Must have ruby if it is not already installed.

# sudo apt-get install ruby

Install SASS

# sudo gem install sass

Install GULP ( assuming you have node.js installed)

# npm install --global gulp-cli

# npm init

# npm install --save-dev gulp

Install GULP for SASS

# npm install --save-dev gulp-sass

Create gulpfile.js with following script

'use strict';
var gulp = require('gulp'); 
var sass = require('gulp-sass'); 
gulp.task('sass', function() {
 gulp.src('./scss/**/*.scss')
 .pipe(sass().on('error', sass.logError))
 .pipe(gulp.dest('./css'));
});
gulp.task('sass:watch', function() {
 gulp.watch('./scss/**/*.scss', ['sass']);
});
 

Then, you can use gulp commands in either way:

# gulp sass

# gulp sass:watch