Use our own (Haskell) pwd to find the tree root

[ghc-hetmet.git] / utils / pwd / pwd.hs

diff --git a/utils/pwd/pwd.hs b/utils/pwd/pwd.hs
new file mode 100644 (file)
index 0000000..264cc98
--- /dev/null
+++ b/utils/pwd/pwd.hs
@@ -0,0 +1,26 @@
+
+module Main where
+
+import System.Directory
+import System.Environment
+
+main :: IO ()
+main = do args <- getArgs
+          let escape = case args of
+                       ["quadruple-backslash"] -> escape_quadruple_backslash
+                       ["forwardslash"] -> escape_forwardslash
+                       _ -> error ("pwd: Bad args: " ++ show args)
+          d <- getCurrentDirectory
+          putStr $ concatMap escape d
+
+-- In prog006 we have to escape \ twice, once to get through sed and
+-- again to get through parsing pkg.conf
+escape_quadruple_backslash :: Char -> String
+escape_quadruple_backslash '\\' = "\\\\\\\\"
+escape_quadruple_backslash c = [c]
+
+-- Normally we can get away with just replacing backslashes with forwardslashes
+escape_forwardslash :: Char -> String
+escape_forwardslash '\\' = "/"
+escape_forwardslash c = [c]
+