add Joule calculator

Author: Robert

joules.c

@@ -0,0 +1,29 @@
+/* Compile with gcc -Wall -o joules joules.c -lm
+    The Lightning Stalker 2023/12/14 */
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <locale.h>
+
+int main (int argc, char **argv)
+{
+    unsetenv ("LC_ALL");
+    setlocale (LC_NUMERIC, "");  // This should give us digit grouping
+
+    if (argc == 3)
+    {
+        printf ("%'.3f\n", 0.0000005 * atof(argv[1]) * \
+            powf(atof(argv[2]), 2));
+        return (0);
+    }
+    else
+    {
+        puts ("joules is a simple capacitor joule calculator.");
+        puts ("output is stored energy in joules\n");
+        puts ("Usage: joules microfarads volts");
+        puts ("Example: joules 33 330");
+        puts ("Output should be: 1.797");
+        return (1);
+    }
+}