var which = require( "which" ), spawn = require( "child_process" ).spawn; try { which.sync( "bower" ); } catch( error ) { console.error( "Bower must be installed to build jQuery." ); console.error( "Please install Bower by running the following command:" ); console.error( "npm install -g bower" ); process.exit( 0 ); } spawn( "bower", [ "install" ], { stdio: 'inherit' } );