old_contents: #!/usr/bin/env node
  'use strict';
  
  var Promise          = require('bluebird'),
      flatten          = require('array-flatten'),
      sassIncludePaths = require('./'),
      sasscIncludeArgs = require('./lib/sassc-include-args');
  
  var argv = require('yargs')
      .boolean('node_modules')
      .boolean('bower_components')
      .boolean('ruby-gems-bundle')
      .boolean('ruby-gems-system')
      .boolean('sassc')
      .argv;
  
  if(!argv['node_modules']     && 
     !argv['bower_components'] && 
     !argv['ruby-gems-bundle'] && 
     !argv['ruby-gems-system']) {
    console.error('Warning: No include path sources selected by user.');
  }
  
  
  var getIncludePaths  = [];
  if(argv['node_modules']) {
    getIncludePaths.push(sassIncludePaths.nodeModules());
  }
  if(argv['bower_components']) {
    getIncludePaths.push(sassIncludePaths.bowerComponents());
  }
  if(argv['ruby-gems-bundle']) {
    getIncludePaths.push(sassIncludePaths.rubyGemsBundle());
  }
  if(argv['ruby-gems-system']) {
    getIncludePaths.push(sassIncludePaths.rubyGemsSystem());
  }
  
  
  Promise.all(getIncludePaths)
  .then(function(gotIncludePaths) {
    return flatten(gotIncludePaths);
  })
  .then(function(includePaths) {
    if(includePaths.length == 0) {
      console.error('Warning: No include paths were found/passed!');
    }
  
    if(argv.sassc) {
      console.log(sasscIncludeArgs(includePaths));
      return;
    }
    console.log(includePaths);
  });
  
new_contents: #!/usr/bin/env node
  'use strict';
  
  var Promise          = require('bluebird'),
      flatten          = require('array-flatten'),
      yargs            = require('yargs'),
      sassIncludePaths = require('./'),
      sasscIncludeArgs = require('./lib/sassc-include-args');
  
  var argv = yargs
  
      .alias('v', 'version')
      .version(function() { return require('./package').version; })
  
      .boolean('node_modules')
      .boolean('bower_components')
      .boolean('ruby-gems-bundle')
      .boolean('ruby-gems-system')
      .boolean('sassc')
  
      .argv;
  
  if(!argv['node_modules']     && 
     !argv['bower_components'] && 
     !argv['ruby-gems-bundle'] && 
     !argv['ruby-gems-system']) {
    console.error('Warning: No include path sources selected by user.');
  }
  
  
  var getIncludePaths  = [];
  if(argv['node_modules']) {
    getIncludePaths.push(sassIncludePaths.nodeModules());
  }
  if(argv['bower_components']) {
    getIncludePaths.push(sassIncludePaths.bowerComponents());
  }
  if(argv['ruby-gems-bundle']) {
    getIncludePaths.push(sassIncludePaths.rubyGemsBundle());
  }
  if(argv['ruby-gems-system']) {
    getIncludePaths.push(sassIncludePaths.rubyGemsSystem());
  }
  
  
  Promise.all(getIncludePaths)
  .then(function(gotIncludePaths) {
    return flatten(gotIncludePaths);
  })
  .then(function(includePaths) {
    if(includePaths.length == 0) {
      console.error('Warning: No include paths were found/passed!');
    }
  
    if(argv.sassc) {
      console.log(sasscIncludeArgs(includePaths));
      return;
    }
    console.log(includePaths);
  });
  
subject: Add cli version swich.