nl_tokens: Returns the extension of the passed file name . It will return an empty string if passed an invalid path .
pl_tokens: function getFileExtension ( <mask> ) { if ( typeof path === 'string' ) { var splitPathRe = / ^(\/?)([\s\S]*?)((?:\.{1,2}|[^\/]+?)(\.([^\.\/\?]+)))(?:[\/]*|[\?].*)$ / i ; var pathParts = splitPathRe . exec ( path ) ; if ( pathParts ) { return pathParts . pop ( ) . toLowerCase ( ) ; } } return '' ; }