dev/random D language

asino.d

@@ -1,23 +1,121 @@
+/**
+	Buridan's Donkey, Asino.
+
+	...a man, being just as hungry as thirsty, 
+	and placed in between food and drink, 
+	must necessarily remain where he is and starve to death.
+
+	- Aristole
+
+    Copyright: Francesco Mecca
+	License: GPLv3
+	Author: Francesco Mecca
+*/
+module asino;
+
 import std.stdio;
 import std.random;
 import std.getopt;
+import std.file;
+import std.conv;
 
 void
 main (string[] args)
 {
-	bool num;
+	bool num = false;
+	string engine = "mt";
 	auto cliOpts = getopt(
 			args,
-			"no-numbers|n", "disable number output on screen", &num);
+			"numbers|n", "enable number output on screen", &num,
+			"engine|e", "Choose the RNG between \"mt\" (Mersenne-Twister, default), \"x\" (xorshift),
+				\"dr\" (/dev/random), \"du\" (/dev/urandom)", &engine
+			);
 
-	args = args[1 .. $];
-	Mt19937 gen;
-	gen.seed (unpredictableSeed);
-	randomShuffle (args);
+    if (cliOpts.helpWanted){
+     	defaultGetoptPrinter("Buridan's Donkey", cliOpts.options);
+     	return;
+ 	}
+
+	args = args[1 .. $]; // remove program name
+	args.shuffle(engine);
+	//writeln(typeid(gen));
 
 	foreach (i, arg; args) {
-		if (num) writeln (arg);
+		if (!num) writeln(arg);
 		else writefln("%s: %s", i, arg);
 	}
-
+}
+
+void shuffle(ref string[] args, string t)
+{
+	if(t == "mt"){
+		Mt19937 gen;
+		gen.seed(unpredictableSeed);
+		args.randomShuffle(gen);
+	} else if (t == "x"){
+		Xorshift32 gen;
+		gen.seed(unpredictableSeed);
+		args.randomShuffle(gen);
+	} else if (t == "du"){
+		auto gen = DevRandomGen!"/dev/urandom"();
+		args.randomShuffle(gen);
+	} else if (t == "dr"){
+		auto gen = DevRandomGen!"/dev/random"();
+		args.randomShuffle(gen);
+	} else {
+		throw new Exception("Wrong arguments");
+	}
+}
+
+
+template DevRandomGen(string gen)
+	if (gen == "/dev/random" || gen == "/dev/urandom")
+{
+	struct DevRandomGen
+	{
+
+		alias UIntType = uint;
+  	  public:
+    	enum bool isUniformRandom = true;
+    	enum empty = false;
+    	/// Smallest generated value.
+    	enum UIntType min = 0;
+    	/// Largest generated value.
+    	enum UIntType max = ubyte.max;
+    	string src = gen;
+
+
+		/**
+	  	  * Unused for /dev/random
+	  	  */
+    	void seed(UIntType x0) @safe pure nothrow @nogc {}
+
+
+    	/**
+     	 * Returns the current number in the random sequence.
+     	 */
+    	@property
+    	UIntType front() const// @safe pure nothrow @nogc
+    	{
+        	//auto a = to!UIntType("/dev/random".read(UIntType.sizeof));
+        	//return to!UIntType(a);
+			return (cast(ubyte[])(src.read(ubyte.sizeof)))[0];
+    	}
+
+
+    	/**
+     	 * Advances the random sequence.
+     	 */
+    	void popFront() @safe pure nothrow @nogc {}
+
+
+    	/**
+     	 * Captures a range state.
+     	 */
+    	@property
+    	typeof(this) save() @safe pure nothrow @nogc
+    	{
+        	return this;
+    	}
+	}
 }