2 files changed, 6 insertions, 0 deletions
diff --git a/src/package.lisp b/src/package.lisp
index 0ea8241..3819017 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -105,6 +105,7 @@
            #:unlines
            #:words
            #:unwords
+           #:strip-prefix
            #:memstr=
            #:define-simple-error
            #:plist-to-long-options
diff --git a/src/util.lisp b/src/util.lisp
index d123e8c..e20b113 100644
--- a/src/util.lisp
+++ b/src/util.lisp
@@ -72,6 +72,11 @@
 (defun unwords (words)
   (format nil "~{~A~^ ~}" words))
 
+(defun strip-prefix (prefix string)
+  "If STRING is prefixed by PREFIX, return the rest of STRING,
+otherwise return NIL."
+  (nth-value 1 (starts-with-subseq prefix string :return-suffix t)))
+
 (defun memstr= (string list)
   (member string list :test #'string=))