CDE

Task/Empty-directory/Haskell/empty-directory-1.hs

@@ -0,0 +1,9 @@
+import System.Directory (getDirectoryContents)
+import System.Environment (getArgs)
+
+
+isEmpty x = getDirectoryContents x >>= return . f . (== [".", ".."])
+    where f True = "Directory is empty"
+          f False = "Directory is not empty"
+
+main = getArgs >>= isEmpty . (!! 0) >>= putStrLn

Task/Empty-directory/Haskell/empty-directory-2.hs

@@ -0,0 +1,5 @@
+$ mkdir 1
+$ ./isempty 1
+Directory is empty
+$ ./isempty /usr/
+Directory is not empty

Task/Empty-directory/Haskell/empty-directory-3.hs

@@ -0,0 +1,15 @@
+procedure main()
+   every dir := "." | "./empty" do
+      write(dir, if isdirempty(dir) then " is empty" else " is not empty")
+end
+
+procedure isdirempty(s)  #: succeeds if directory s is empty (and a directory)
+local d,f
+   if ( stat(s).mode ? ="d" ) & ( d := open(s) ) then {
+         while f := read(d) do
+            if f == ("."|"..") then next else fail
+         close(d)
+         return s
+         }
+   else stop(s," is not a directory or will not open")
+end