diff --git a/o_gnuplot/src/o_gnuplot.cpp b/o_gnuplot/src/o_gnuplot.cpp
index 66a9ec2565c870e06b6897c520d88565170ba5b8..456e57f0131908eb6998f499bf9fdb6c0b3123ea 100644
--- a/o_gnuplot/src/o_gnuplot.cpp
+++ b/o_gnuplot/src/o_gnuplot.cpp
@@ -57,9 +57,6 @@ int main(int argc, char *argv[]){
     int status=0, total_length;
     uint32_t type;
     int dims_nb;
-
-    fprintf(stderr, "start graph %s\n", history_str);
-
     
     blc_program_set_description("Display the content of the blc_channel depending on its type and format");
     blc_program_add_option(&verbatim, 'c', "command", "string", "command directly send to gnuplot", NULL);
@@ -76,15 +73,9 @@ int main(int argc, char *argv[]){
     blc_program_add_option(&refresh_string, 'P', "period", "UI32", "graph refresh period in ms", "100");
     blc_program_add_option(&window_string, 'W', "window", "string", "window posistion and size: 'px,py,sx,sy'", nullptr);
     blc_program_add_multiple_parameters(&channel_names, "blc_channel", -1, "channel you want to graph");
-
     blc_program_init(&argc, &argv, blc_quit);
-    fprintf(stderr, "init done graph %s\n", history_str);
-
     blc_command_forward_blc_channels();
 
-    fprintf(stderr, "param done graph %s\n", history_str);
-
-
     for (char *const*channel_name_pt = channel_names; *channel_name_pt!=nullptr; channel_name_pt++){
         inputs.emplace_back();
         new (&inputs.back()) blc_channel(*channel_name_pt, BLC_CHANNEL_READ);
@@ -149,9 +140,6 @@ int main(int argc, char *argv[]){
         fprintf(pipef, "set term qt 1 position %d,%d size %d,%d\n", px, py, sx, sy);
     }
 
-    fprintf(stderr, "before graph %s\n", history_str);
-
-
     if (history_str) create_history_graph(pipef, inputs, strtol(history_str, NULL, 10), sampling_period, strtol(sample_string, NULL, 10)*1000, ymin, ymax);
     else create_graph(pipef, inputs, sampling_period, ymin, ymax, xmin, xmax, lmax);