diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # Revision history for simple-cmd
 
+## 0.2.1 (2019-12-12)
+- add cmdTry_: only runs if available
+- add ifM and whenM
+- add needProgram
+
 ## 0.2.0 (2019-06-03)
 - add warning command
 - API change: sudo and sudo_
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 [![Build Status](https://travis-ci.org/juhp/simple-cmd.png)](https://travis-ci.org/juhp/simple-cmd)
 [![Hackage](http://img.shields.io/hackage/v/simple-cmd.png)](http://hackage.haskell.org/package/simple-cmd)
+[![Stackage LTS](http://stackage.org/package/simple-cmd/badge/lts)](http://stackage.org/lts/package/simple-cmd)
+[![Stackage Nightly](http://stackage.org/package/simple-cmd/badge/nightly)](http://stackage.org/nightly/package/simple-cmd)
 
 # simple-cmd
 
diff --git a/SimpleCmd.hs b/SimpleCmd.hs
--- a/SimpleCmd.hs
+++ b/SimpleCmd.hs
@@ -29,7 +29,7 @@
 module SimpleCmd (
   cmd, cmd_,
   cmdBool,
-  cmdIgnoreErr,
+  cmdIgnoreErr, {- badly named -}
   cmdLines,
   cmdMaybe,
   cmdLog, cmdlog {-TODO: remove for 0.3 -},
@@ -38,9 +38,12 @@
   cmdSilent,
   cmdStdIn,
   cmdStdErr,
+  cmdTry_,
   error',
   egrep_, grep, grep_,
+  ifM,
   logMsg,
+  needProgram,
   removePrefix, removeStrictPrefix, removeSuffix,
   shell, shell_,
   shellBool,
@@ -49,6 +52,7 @@
   PipeCommand,
   pipe, pipe_, pipeBool,
   pipe3_, pipeFile_,
+  whenM,
   (+-+)) where
 
 #if (defined(MIN_VERSION_base) && MIN_VERSION_base(4,8,0))
@@ -58,7 +62,7 @@
 import Control.Monad
 
 import Data.List (stripPrefix)
-import Data.Maybe (isNothing, fromMaybe)
+import Data.Maybe (isJust, isNothing, fromMaybe)
 
 import System.Directory (findExecutable)
 import System.Exit (ExitCode (..))
@@ -206,6 +210,15 @@
   (_exit, out, _err) <- readProcessWithExitCode c args input
   return out
 
+-- | 'cmdTry_ c args' runs the command if available
+--
+-- @since 0.2.1
+cmdTry_ :: String -> [String] -> IO ()
+cmdTry_ c args = do
+  have <- findExecutable c
+  when (isJust have) $
+    cmd_ c args
+
 -- | 'grep pat file' greps pattern in file, and returns list of matches
 --
 -- @since 0.1.2
@@ -288,6 +301,10 @@
 warning :: String -> IO ()
 warning = hPutStrLn stderr
 
+
+-- | Type alias for a command in a pipe
+--
+-- @since 0.2.0
 type PipeCommand = (String,[String])
 
 -- | Return stdout from piping the output of one process to another
@@ -354,3 +371,26 @@
       void $ waitForProcess p1
       void $ waitForProcess p2
 
+-- | Monadic if
+-- @ifM test actTrue actFalse@
+-- (taken from protolude)
+--
+-- @since 0.2.1
+ifM :: Monad m => m Bool -> m a -> m a -> m a
+ifM p x y = p >>= \b -> if b then x else y
+
+-- | Monadic when
+-- @whenM test action@
+--
+-- @since 0.2.1
+whenM :: Monad m => m Bool -> m () -> m ()
+whenM p x = p >>= \b -> when b x
+
+-- | Assert program in PATH
+-- @needProgram progname@
+--
+-- @since 0.2.1
+needProgram :: String -> IO ()
+needProgram prog = do
+  mx <- findExecutable prog
+  unless (isJust mx) $ error' $ "program needs " ++ prog
diff --git a/simple-cmd.cabal b/simple-cmd.cabal
--- a/simple-cmd.cabal
+++ b/simple-cmd.cabal
@@ -1,5 +1,5 @@
 name:                simple-cmd
-version:             0.2.0.1
+version:             0.2.1
 synopsis:            Simple String-based process commands
 description:
             Simple wrappers over System.Process
@@ -17,7 +17,8 @@
 cabal-version:       >=1.10
 extra-source-files:  README.md ChangeLog.md TODO
 tested-with:         GHC == 7.4.2, GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.3,
-                     GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4, GHC == 8.6.5
+                     GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.4, GHC == 8.6.5,
+                     GHC == 8.8.1
 
 source-repository head
   type:     git
@@ -27,7 +28,11 @@
   exposed-modules:     SimpleCmd,
                        SimpleCmd.Git,
                        SimpleCmd.Rpm
-  build-depends:       base < 5, directory, filepath, process >= 1.4.3.0, unix
+  build-depends:       base < 5,
+                       directory,
+                       filepath,
+                       process >= 1.4.3.0,
+                       unix
   default-language:    Haskell2010
   default-extensions:  CPP
   ghc-options:   -fwarn-missing-signatures -Wall