#include static void print_hello (GtkWidget *widget, gpointer data) { g_print ("Hello World\n"); } static void activate (GtkApplication *app, gpointer user_data) { GtkWidget *window; GtkWidget *button; gtk_application_set window = gtk_application_window_new (app); gtk_window_set_title (GTK_WINDOW (window), "Hello World"); gtk_window_set_default_size (GTK_WINDOW (window), 250, 200); button = gtk_button_new_with_label ("Hello World"); g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL); gtk_window_set_child (GTK_WINDOW (window), button); gtk_window_present (GTK_WINDOW (window)); } int main (int argc, char **argv) { GtkApplication *app; int status; app = gtk_application_new ("dev.kevink.example", G_APPLICATION_DEFAULT_FLAGS); g_signal_connect (app, "activate", G_CALLBACK (activate), NULL); status = g_application_run (G_APPLICATION (app), argc, argv); g_object_unref (app); return status; } // gcc $(pkg-config --cflags gtk4) -o hello-world-gtk hello-world.c $(pkg-config --libs gtk4) && ./hello-world-gtk