Found a way to unify the hdr_output_folder so that it's set across both

the publisher and the camera_simulator with just the flag

event_camera_simulator/esim_common/CMakeLists.txt

@@ -9,10 +9,12 @@ catkin_simple()
 set(HEADERS
     include/esim/common/types.hpp
     include/esim/common/utils.hpp
+    include/esim/common/hdr.hpp
 )
 
 set(SOURCES
     src/utils.cpp
+    src/hdr.cpp
 )
 
 cs_add_library(${PROJECT_NAME} ${SOURCES} ${HEADERS})

event_camera_simulator/esim_common/include/esim/common/hdr.hpp

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <gflags/gflags.h>
+
+extern std::string hdr_output_folder;

event_camera_simulator/esim_common/src/hdr.cpp

@@ -0,0 +1,9 @@
+#include "esim/common/hdr.hpp"
+
+DEFINE_string(
+    hdr_output_folder,
+    "/home/arno/sim_ws/out",
+    "Folder in which to output the events."
+);
+
+std::string hdr_output_folder = FLAGS_hdr_output_folder;