Added a basic dice roller.

I built a basic dice roller because I needed one.
I want to add a few more features later on, though.

roll.c

@@ -0,0 +1,52 @@
+// roll.c: A command line dice roller.
+#include <time.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+typedef struct roll
+{
+	unsigned diceSides;
+	unsigned numberOfDice;
+} roll;
+
+roll parseRollString(char * rollString)
+{
+	char * numberString, * sidesString, * currentPointer;
+	currentPointer = rollString;
+	numberString = strtok_r(rollString, "dD", &currentPointer);
+	sidesString = strtok_r(NULL, "dD", &currentPointer);
+	roll roll;
+	roll.numberOfDice = (unsigned)atoi(numberString);
+	roll.diceSides = (unsigned)atoi(sidesString);
+	return roll;
+}
+
+int rollDice(roll roll)
+{
+	int rolledValue = 0;
+	for(unsigned rolls = 0; rolls < roll.numberOfDice; rolls++)
+	{
+		rolledValue += (rand() % roll.diceSides) + 1;
+	}
+	return rolledValue;
+}
+
+int main(int argc, char ** argv)
+{
+	srand((unsigned)time(NULL) * getpid());
+	roll roll;
+	if(argc < 1)
+	{
+		roll = parseRollString(argv[1]);
+	}
+	else
+	{
+		roll.diceSides = 20;
+		roll.numberOfDice = 1;
+	}
+	int result = rollDice(roll);
+	printf("You rolled a: %d\n", result);
+	return result;
+}