check number of arguments

imgui.ini

@@ -8,7 +8,7 @@ Size=1152,1414
 
 [Window][main]
 Pos=0,0
-Size=1211,806
+Size=1282,1414
 
 [Window][Hex View]
 Pos=91,62

src/platform_linux.h

@@ -22,8 +22,10 @@ bool os_open_and_map_file(const char *fname, App_State &app)
   size_t fsize = file_size(file);
 
   void *fmem = mmap(0, fsize, PROT_READ, MAP_SHARED_VALIDATE, fd, 0);
-  if (!fmem)
+  if (!fmem) {
     fprintf(stderr, "Failed to open file %s\n", fname);
+    return false;
+  }
 
   app.inspected_file.name = str8(fname);
   app.inspected_file.stream = file;

src/render.cpp

@@ -155,7 +155,7 @@ void make_viewer(App_State &app)
   COL(col_page_start, 200, 0, 200);
   COL(col_checksum, 134, 65, 25);
   COL(col_page_list, 60, 110, 120);
-  COL(col_highlight, 160, 160, 160);
+  COL(col_highlight, 190, 190, 190);
 #undef COL
 
   app.viewer = viewer;

src/rntviewer.cpp

@@ -82,7 +82,7 @@ int main(int argc, char **argv)
   tctx_init(tctx);
   defer { tctx_release(); };
   
-  if (argc > 1 && argv[1][0] == '-') {
+  if ((argc > 1 && argv[1][0] == '-') || argc < 3) {
     fprintf(stderr, "Usage: %s <ntuple_name> <ntuple_file.root>\n", argv[0]);
     return 1;
   }