Fixes in 2000/primenum - int main from void main

To make the entry more portable the void main was changed to int main.

The no arg check was NOT fixed: this is a documented feature not a bug
and should not be fixed. If one wants to fix it for personal enjoyment
(if they can get pleasure from a couple seconds :-) ) they may do so but
it is not to be committed.

2000/primenum/primenum.c

@@ -1,8 +1,8 @@
-#define BeginProgram void main(int argc, char *argv[])
+#define BeginProgram int main(int argc, char *argv[])
 #define CloseBrace }
 #define CommandLineArgument -1
 #define Declare int i,j,n,Flag=1;
-#define EndOfProgram return;
+#define EndOfProgram return 0;
 #define False 0;
 #define ForLoop ;for
 #define GetCommandLineArgument n=atoi(argv[1]);

thanks-for-fixes.md

@@ -1657,6 +1657,11 @@ itself a one-line like the code is in the original entry. Now it looks much more
 like the original entry but with the two fixes.
 
 
+## [2000/primenum](2000/primenum/primenum.c) ([README.md](2000/primenum/README.md]))
+
+Cody made this more portable by changing the `void main` to `int main`.
+
+
 ## [2000/thadgavin](2000/thadgavin/thadgavin.c) ([README.md](2000/thadgavin/README.md]))
 
 Cody fixed the code and added an appropriate make rule so that the SDL version