Save utfile and nthreads to savefile

src/navier-stokes.c

@@ -160,7 +160,8 @@ int enstrophy(
   // for interrupt recovery
   char* cmd_string,
   char* params_string,
-  char* savefile_string
+  char* savefile_string,
+  char* utfile_string
 ){
   _Complex double* u;
   _Complex double* tmp1;
@@ -293,6 +294,16 @@ int enstrophy(
       }
       fprintf(savefile,"\"");
     }
+
+    // utfile
+    if(utfile!=NULL){
+      fprintf(savefile," -u \"%s\"", utfile_string);
+    }
+    // threads
+    if(nthreads!=1){
+      fprintf(savefile," -t %d", nthreads);
+    }
+
     fprintf(savefile," enstrophy\n");
 
     // save final u to savefile