file-extension

Description

Returns the extension of a filename. The extension is the last "."-delimited part of the name. Returns "" if there is no period in the filename.

Author

Norman Walsh, <ndw@nwalsh.com>

Source Code

(define (file-extension filespec) 
  ;; Return the extension of a filename
  (if (string? filespec)
      (let* ((pathparts (match-split filespec "/"))
	     (filename  (list-ref pathparts (- (length pathparts) 1)))
	     (fileparts (match-split filename "."))
	     (extension (list-ref fileparts (- (length fileparts) 1))))
	(if (> (length fileparts) 1)
	    extension
	    ""))
      ""))