Sass is a professional grade CSS extension language. The following commands will convert SCSS or Sass files to CSS.

# Output converted file to stdout:
sass <inputfile.scss|inputfile.sass>

# Immediately convert SCSS or Sass file to CSS to specified output file:
sass <inputfile.scss|inputfile.sass> <outputfile.css>

# Watch SCSS or Sass file for changes and output or update CSS file with same filename:
sass --watch <inputfile.scss|inputfile.sass>

# Watch SCSS or Sass file for changes and output or update CSS file with specified filename:
sass --watch <inputfile.scss|inputfile.sass>:<outputfile.css>