make -k quit after printing the key list

src/argparse.cpp

@@ -9,7 +9,7 @@ void print_help(const char *argv0)
     "\n\t-e: display some extended info(*) (may slow down the startup)"
     "\n\t-h: display this help and exit"
     "\n\t-l: display LEN bytes (only in terminal mode)"
-    "\n\t-k: print information about the TKeys in the file"
+    "\n\t-k: print information about the TKeys in the file and exit"
     "\n\t-n: list the names of the RNTuples found in the file and exit"
     "\n\t-s: set first displayed byte to START"
     "\n\t-t: no graphics, output to terminal"

src/rntviewer.cpp

@@ -176,6 +176,8 @@ int main(int argc, char **argv)
     }
     return 0;
   }
+  if (args.print_keys_info)
+    return 0;
 
   if (success)
     app.fdata.rndata = get_rntuple_data(app.fdata.arena, app.inspected_file, app.fdata.tfile_data, args.extended_info);

src/tfile.cpp

@@ -219,6 +219,9 @@ b8 walk_tkeys(Arena *arena, const u8 *data, u64 data_len, u32 flags, TFile_Data
     }
  
     if (is_free_slot) {
+      if (flags & WTK_PRINT_KEYS_INFO) {
+        printf("Free Slot at 0x%lX, len: %d (%s)\n", cur, n_bytes, to_pretty_size(scratch.arena, n_bytes).c());
+      }
       // don't try to read the rest of the data
       cur += n_bytes;
       continue;