diff --git a/CHANGELOG b/CHANGELOG
new file mode 100644
--- /dev/null
+++ b/CHANGELOG
@@ -0,0 +1,13 @@
+shell-monad (0.0.2) unstable; urgency=medium
+
+  * Better constructing of pipes.
+  * Added whileCmd, ifCmd, whenCmd, and unlessCmd.
+  * Added stopOnFailure and ignoreFailure.
+
+ -- Joey Hess <id@joeyh.name>  Thu, 25 Dec 2014 01:11:34 -0400
+
+shell-monad (0.0.1) unstable; urgency=medium
+
+  * First release.
+
+ -- Joey Hess <id@joeyh.name>  Wed, 24 Dec 2014 19:23:44 -0400
diff --git a/Control/Monad/Shell.hs b/Control/Monad/Shell.hs
--- a/Control/Monad/Shell.hs
+++ b/Control/Monad/Shell.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE DeriveFunctor #-}
 
 module Control.Monad.Shell (
 	Script,
@@ -10,6 +11,8 @@
 	linearScript,
 	Var,
 	val,
+	Q,
+	quote,
 	Expr,
 	indent,
 	run,
@@ -20,15 +23,21 @@
 	newVarContaining,
 	globalVar,
 	func,
+	(-|-),
 	forCmd,
-	quote,
+	whileCmd,
+	ifCmd,
+	whenCmd,
+	unlessCmd,
 	readVar,
-	(-|-),
+	stopOnFailure,
+	ignoreFailure,
 ) where
 
 import qualified Data.Text.Lazy as L
 import qualified Data.Set as S
 import Data.Monoid
+import Control.Applicative
 import Data.Char
 
 -- | A shell variable.
@@ -81,6 +90,7 @@
 
 -- | Shell script monad.
 newtype Script a = Script (Env -> ([Expr], Env, a))
+	deriving (Functor)
 
 instance Monad Script where
         return ret = Script $ \env -> ([], env, ret)
@@ -158,7 +168,7 @@
 -- | Variadic argument version of 'run'.
 --
 -- The command can be passed any number of arguments.
--- As well as passing Text arguments, it also accepts Var arguments,
+-- As well as passing Text and Q arguments, it also accepts Var arguments,
 -- which passes the value of a shell variable to the command.
 --
 -- Convenient usage of 'cmd' requires the following:
@@ -166,7 +176,7 @@
 -- > {-# LANGUAGE OverloadedStrings, ExtendedDefaultRules #-}
 -- > {-# OPTIONS_GHC -fno-warn-type-defaults #-}
 -- > import Control.Monad.Shell
--- > import qualified Data.Text.Lazy as T
+-- > import qualified Data.Text.Lazy as L
 -- > default (L.Text)
 --
 -- This allows writing, for example:
@@ -250,7 +260,7 @@
 	    (ls, env'') = eval env' s
 	in (definefunc f ls, env'', callfunc f)
   where
-	basename = "f"
+	basename = "p"
 	go env x
 		| S.member f (envFuncs env) = go env (succ x)
 		| otherwise = f
@@ -262,6 +272,16 @@
 	callfunc :: Func -> Script ()
 	callfunc (Func f) = add $ Cmd f
 
+-- | Pipes together two Scripts.
+(-|-) :: Script () -> Script () -> Script ()
+a -|- b = do
+	alines <- runM a
+	blines <- runM b
+	add $ Pipe (toExp alines) (toExp blines)
+  where
+	toExp [e] = e
+	toExp l = Subshell L.empty l
+
 -- | Runs the command, and separates its output into parts
 -- (using the IFS)
 --
@@ -269,23 +289,81 @@
 forCmd :: Script () -> (Var -> Script ()) -> Script ()
 forCmd c a = do
 	v@(Var vname) <- newVar "x"
-	cmdlines <- runM c
-	add $ Cmd $ "for " <> vname <> " in $(" <> toLinearScript cmdlines <> ")"
-	-- Using : as the first command in the loop ensures that the loop
-	-- body is not empty, and allows for more regular indentation.
-	add $ Cmd "do :"
-	mapM_ (add . indent) =<< runM (a v)
+	s <- toLinearScript <$> runM c
+	add $ Cmd $ "for " <> vname <> " in $(" <> s <> ")"
+	block "do" (a v)
 	add $ Cmd "done"
 
+-- | As long as the first Script exits nonzero, runs the second script.
+whileCmd :: Script () -> Script () -> Script ()
+whileCmd c a = do
+	s <- toLinearScript <$> runM c
+	add $ Cmd $ "while $(" <> s <> ")"
+	block "do" a
+	add $ Cmd "done"
+
+-- | if with a monadic conditional
+--
+-- If the conditional exits 0, the first action is run, else the second.
+ifCmd :: Script () -> Script () -> Script () -> Script ()
+ifCmd cond thena elsea = 
+	ifCmd' id cond $ do
+		block "then" thena
+		block "else" elsea
+
+ifCmd' :: (L.Text -> L.Text) -> Script () -> Script () -> Script ()
+ifCmd' condf cond body = do
+	condl <- runM cond
+	add $ Cmd $ "if " <> condf (singleline condl)
+	body
+	add $ Cmd "fi"
+  where
+	singleline l =
+		let c = case l of
+			[c'@(Cmd {})] -> c'
+			[c'@(Subshell {})] -> c'
+			_ -> Subshell L.empty l
+		in toLinearScript [c]
+
+-- | when with a monadic conditional
+whenCmd :: Script () -> Script () -> Script ()
+whenCmd cond a = 
+	ifCmd' id cond $
+		block "then" a
+
+-- | unless with a monadic conditional
+unlessCmd :: Script () -> Script () -> Script ()
+unlessCmd cond a =
+	ifCmd' ("! " <>) cond $
+		block "then" a
+
+-- | Creates a block such as "do : ; cmd ; cmd" or "else : ; cmd ; cmd"
+--
+-- The use of : ensures that the block is not empty, and allows
+-- for more regular indetnetion, as well as making the single line
+-- formatting work.
+block :: L.Text -> Script () -> Script ()
+block word s = do
+	add $ Cmd $ word <> " :"
+	mapM_ (add . indent) =<< runM s
+
 -- | Generates shell code to read a variable from stdin.
 readVar :: Var -> Script ()
 readVar (Var vname) = add $ Cmd $ "read " <> getQ (quote vname)
 
--- | Pipes together two Scripts.
-(-|-) :: Script () -> Script () -> Script ()
-a -|- b = do
-	alines <- runM a
-	blines <- runM b
-	add $ case (alines, blines) of
-		([ca@(Cmd{})], [cb@(Cmd{})]) -> Pipe ca cb
-		_ -> Pipe (Subshell L.empty alines) (Subshell L.empty blines)
+-- | By default, shell scripts continue running past commands that exit
+-- nonzero. Use "stopOnFailure True" to make the script stop on the first
+-- such command.
+stopOnFailure :: Bool -> Script ()
+stopOnFailure b = add $ Cmd $ "set " <> if b then "-" else "+" <> "x"
+
+-- | Makes a nonzero exit status be ignored.
+ignoreFailure :: Script () -> Script ()
+ignoreFailure s = runM s >>= mapM_ (add . go)
+  where
+	go (Cmd t) = Cmd $ t <> " || true"
+	go c@(Comment _) = c
+	go c@(HereDocBody _) = c
+	go (Subshell i l) = Subshell i (map go l)
+	-- Assumes pipefail is not set.
+	go (Pipe e1 e2) = Pipe e1 (go e2)
diff --git a/examples/santa.hs b/examples/santa.hs
new file mode 100644
--- /dev/null
+++ b/examples/santa.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE OverloadedStrings, ExtendedDefaultRules #-}
+{-# OPTIONS_GHC -fno-warn-type-defaults #-}
+import Control.Monad.Shell
+import qualified Data.Text.Lazy as T
+import qualified Data.Text.Lazy.IO as T
+import Data.Monoid
+default (T.Text)
+
+main :: IO ()
+main = T.writeFile "santa.sh" $ script $ do
+	hohoho <- func $
+		cmd "echo" "Ho, ho, ho!" "Merry xmas!"
+	hohoho
+
+	promptFor "What's your name?" $ \name -> pipeLess $ do
+		cmd "echo" "Let's see what's in" (val name <> quote "'s") "stocking!"
+		forCmd (cmd "ls" "-1" (quote "/home/" <> val name)) $ \f -> do
+			cmd "echo" "a shiny new" f
+			hohoho
+
+	cmd "rm" "/table/cookies" "/table/milk"
+	hohoho
+
+pipeLess :: Script () -> Script ()
+pipeLess c = c -|- cmd "less"
+
+promptFor :: T.Text -> (Var -> Script ()) -> Script ()
+promptFor prompt cont = do
+	cmd "printf" (prompt <> " ")
+	var <- newVar "prompt"
+	readVar var
+	cont var
diff --git a/santa.hs b/santa.hs
deleted file mode 100644
--- a/santa.hs
+++ /dev/null
@@ -1,32 +0,0 @@
-{-# LANGUAGE OverloadedStrings, ExtendedDefaultRules #-}
-{-# OPTIONS_GHC -fno-warn-type-defaults #-}
-import Control.Monad.Shell
-import qualified Data.Text.Lazy as T
-import qualified Data.Text.Lazy.IO as T
-import Data.Monoid
-default (T.Text)
-
-main :: IO ()
-main = T.writeFile "santa.sh" $ script $ do
-	hohoho <- func $
-		cmd "echo" "Ho, ho, ho!" "Merry xmas!"
-	hohoho
-
-	promptFor "What's your name?" $ \name -> pipeLess $ do
-		cmd "echo" "Let's see what's in" (val name <> quote "'s") "stocking!"
-		forCmd (cmd "ls" "-1" (quote "/home/" <> val name)) $ \f -> do
-			cmd "echo" "a shiny new" f
-			hohoho
-
-	cmd "rm" "/table/cookies" "/table/milk"
-	hohoho
-
-pipeLess :: Script () -> Script ()
-pipeLess c = c -|- cmd "less"
-
-promptFor :: T.Text -> (Var -> Script ()) -> Script ()
-promptFor prompt cont = do
-	cmd "printf" (prompt <> " ")
-	var <- newVar "prompt"
-	readVar var
-	cont var
diff --git a/shell-monad.cabal b/shell-monad.cabal
--- a/shell-monad.cabal
+++ b/shell-monad.cabal
@@ -1,5 +1,5 @@
 Name: shell-monad
-Version: 0.0.1
+Version: 0.0.2
 Cabal-Version: >= 1.8
 License: BSD3
 Maintainer: Joey Hess <id@joeyh.name>
@@ -13,7 +13,8 @@
 Description:
  This is a shell monad, for generating shell scripts.
 Extra-Source-Files:
-  santa.hs
+  CHANGELOG
+  examples/santa.hs
 
 Library
   GHC-Options: -Wall