diff -r 39774ec26126 -r 5e1012e665bf samples/exec.js
--- a/samples/exec.js	Tue Apr 26 13:31:55 2016 -0700
+++ b/samples/exec.js	Wed May 11 14:20:49 2016 +0200
@@ -39,9 +39,10 @@
 $EXEC("cat", "Hello, world!")
 
 // Additional arguments can be passed after the stdin argument, as an array of
-// strings, or a sequence of varargs:
-$EXEC("ls", "" /* no stdin */, "-l", "-a")
-$EXEC("ls", "" /* no stdin */, ["-l", "-a"])
+// strings, or a sequence of varargs (if there is no stdin, null or undefined
+// can be passed):
+$EXEC("ls", undefined, "-l", "-a")
+$EXEC("ls", undefined, ["-l", "-a"])
 
 // Output of running external commands is returned from $EXEC:
 print($EXEC("ls"))