Add stdinIsTTY (purescript-node#30)

Author: matoruru

src/Node/Process.purs

@@ -20,6 +20,7 @@ module Node.Process
   , stdin
   , stdout
   , stderr
+  , stdinIsTTY
   , stdoutIsTTY
   , stderrIsTTY
   , version
@@ -151,6 +152,11 @@ stdout = process.stdout
 stderr :: Writable ()
 stderr = process.stderr
 
+-- | Check whether the standard input stream appears to be attached to a TTY.
+-- | It is a good idea to check this before processing the input data from stdin.
+stdinIsTTY :: Boolean
+stdinIsTTY = process.stdin.isTTY
+
 -- | Check whether the standard output stream appears to be attached to a TTY.
 -- | It is a good idea to check this before printing ANSI codes to stdout
 -- | (e.g. for coloured text in the terminal).