File.extname(path) â string
Class Public methods
Returns the extension (the portion of file name in path
starting from the last period).
If path is a dotfile, or starts with a period, then the
starting dot is not dealt with the start of the extension.
An empty string will also be returned when the period is the last character
in path.
File.extname("test.rb") #=> ".rb"
File.extname("a/b/d/test.rb") #=> ".rb"
File.extname("foo.") #=> ""
File.extname("