Need close GTK+ window after execute the function - c

Question

I am programming on linux program and I am trying to prepare program with GTK+3, but I don't know how close program automatically after execute the function without kill that execute.
the step that i want in my program is:
open gtk window and this window there is button (open Xreader).
press button, it tells system to execute xreader program.
close gtk window automatically without needing to close xreader .
here is my code
#include<stdio.h>
#include<gtk/gtk.h>
static void
open_app(GtkWidget *Widget, gpointer data){
system("xreader");
gtk_main_quit();
}
int main(int argc, char *argv[])
{
GtkWidget *window;
GtkWidget *button1;
gtk_init(&argc, &argv);
/*make window */
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
/*give name to the window*/
gtk_window_set_title(GTK_WINDOW(window), "launcher");
/*make size of window*/
gtk_window_set_default_size(GTK_WINDOW(window), 700, 700);
/*open the window in the meddal*/
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
button1 = gtk_button_new_with_label("Open Xreader");
gtk_container_add(GTK_CONTAINER(window), button1);
gtk_widget_show_all(window);
g_signal_connect(button1,"clicked",G_CALLBACK(open_app), NULL);
g_signal_connect(window, "destroy",
G_CALLBACK(gtk_main_quit), NULL);
gtk_main();
return 0;
}
everytime trying to execute my program and press the button (open Xreader) gtk not close till close xreader .

Answer 1

You cannot use system here, because according to its documentation, https://man7.org/linux/man-pages/man3/system.3.html
system() returns after the command has been completed.
Since you are using gtk, don't forget library functions provided by glib. It has a bunch of functions related to process and thread handling. For example, you can use GSubprocess class from glib, g_subprocess_new.
#include <gtk/gtk.h>
#include <stdio.h>
#include <stdlib.h>
#include <glib.h>
static void open_app(GtkWidget *Widget, gpointer data) {
g_subprocess_new(G_SUBPROCESS_FLAGS_NONE, NULL, "xreader", NULL);
gtk_main_quit();
}
int main(int argc, char *argv[]) {
GtkWidget *window;
GtkWidget *button1;
gtk_init(&argc, &argv);
/*make window */
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
/*give name to the window*/
gtk_window_set_title(GTK_WINDOW(window), "launcher");
/*make size of window*/
gtk_window_set_default_size(GTK_WINDOW(window), 700, 700);
/*open the window in the meddal*/
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
button1 = gtk_button_new_with_label("Open Xreader");
gtk_container_add(GTK_CONTAINER(window), button1);
gtk_widget_show_all(window);
g_signal_connect(button1, "clicked", G_CALLBACK(open_app), NULL);
g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
gtk_main();
return 0;
}