Compile 2 versions: old + PC11, and add some error checks

Author: JayFoxRox

Diff for: CMakeLists.txt

@@ -1,6 +1,9 @@
 set(CMAKE_C_STANDARD 11)
 
 add_executable(pba-rez rez.c)
+add_executable(pba-rez-pc11 rez.c)
+target_compile_definitions(pba-rez-pc11 PRIVATE -DPC11)
+
 add_executable(pba-csv csv.c json.h)
 add_executable(format0001 format0001.c)
 add_executable(format0022 format0022.c)

Diff for: rez.c

@@ -1,5 +1,3 @@
-#define PC11 //FIXME: Make this a CLI option
-
 #include <stdbool.h>
 #include <assert.h>
 #include <stdint.h>
@@ -175,9 +173,21 @@ void export(FILE* f, FileHeader* fileHeader, const char* path, bool compressed)
 }
 
 int main(int argc, char* argv[]) {
-  FILE* f = fopen(argv[1], "rb");
+
+  if (argc != 3) {
+    printf("Usage: %s <rez-file-path> <output-folder-path>\n", argv[0]);
+    return 1;
+  }
+
+  const char* inPath = argv[1];
   const char* outPath = argv[2];
 
+  FILE* f = fopen(inPath, "rb");
+  if (f == NULL) {
+    printf("Could not open '%s'\n", inPath);
+    return 1;
+  }
+
   // This is the actual header
 
   fseek(f, -2048, SEEK_END);