Ensure ROOT is in batch mode (#207)

Co-authored-by: Juan Miguel Carceller <[email protected]>

k4FWCore/scripts/k4run

@@ -148,6 +148,12 @@ def main():
         help="Print all the configurable components available in the framework and exit",
     )
     parser.add_argument("--gdb", action="store_true", help="Attach gdb debugger")
+    parser.add_argument(
+        "--interactive-root",
+        action="store_true",
+        help="Run with ROOT in interactive mode (e.g. to see plots)",
+        default=False,
+    )
 
     # Once to parse the files and another time below to have the new parameters
     # in the namespace since parsing of the file happens when the namespace
@@ -229,6 +235,11 @@ def main():
 
     c = gaudimain()
     if not opts.dry_run:
+        if not opts.interactive_root:
+            from ROOT import gROOT
+
+            gROOT.SetBatch(True)
+
         # Do the real processing
         retcode = c.run(opts.gdb)
         # User requested stop returns non-zero exit code see: https://github.com/key4hep/k4FWCore/issues/125