help me to check whether this is the correct way to compile c source to library ...

i try to compile a gtk example program i copied from the net into a share library ... it did managed to compile , i can also run the main app calling the function to run the gtk program ... but i'm still not sure whether this is the "correct" way to do it ... if anybody found anything weird , please give me some hints and directions ...

callgtk02.h

#ifndef _CALLGTK02_H_
#define _CALLGTK02_H_ 1

#undef __BEGIN_DECLS
#undef __END_DECLS
#ifdef __cplusplus
# define __BEGIN_DECLS extern "C" {
# define __END_DECLS }
#else
# define __BEGIN_DECLS 
# define __END_DECLS 
#endif

__BEGIN_DECLS
extern char *call_gtk02(char *pass_strings);
__END_DECLS

#endif

callgtk02.c

#include <stdio.h>
#include <gtk/gtk.h>
#include <glib.h>
#include "callgtk02.h"

GtkWidget *file_selection_box;
gchar *filename;

gint destroyapp (GtkWidget *widget, gpointer gdata)
{
  g_print ("\n\nQuitting gtk ...\n\n");
  gtk_main_quit();
  return (FALSE);
}

void store_filename(GtkFileSelection *file_selection, gpointer data)
{
  filename = gtk_file_selection_get_filename(GTK_FILE_SELECTION(file_selection_box));
  g_print (filename);
}

void create_file_selection(void) 
{
  file_selection_box = gtk_file_selection_new("Please select a file for editing.");
  gtk_signal_connect (GTK_OBJECT (GTK_FILE_SELECTION(file_selection_box)->ok_button), "clicked", GTK_SIGNAL_FUNC (store_filename), NULL);
  gtk_signal_connect_object (GTK_OBJECT (GTK_FILE_SELECTION(file_selection_box)->ok_button), "clicked", GTK_SIGNAL_FUNC (gtk_widget_destroy), (gpointer) file_selection_box);
  gtk_signal_connect_object (GTK_OBJECT (GTK_FILE_SELECTION(file_selection_box)->cancel_button), "clicked", GTK_SIGNAL_FUNC (gtk_widget_destroy), (gpointer) file_selection_box);
  gtk_widget_show (file_selection_box);
}
  
gint ClosingAppWindow (GtkWidget *widget, gpointer gdata)
{
  g_print ("\n\nQuitting gtk ...\n\n");
  gtk_main_quit();
  return (FALSE);
}

char *call_gtk02(char *pass_strings)
//int main (int argc, char *argv[])
{
  GtkWidget *window;
  GtkWidget *menuFile;
  GtkWidget *menuEdit;
  GtkWidget *menuHelp;  
  GtkWidget *menubar;
  GtkWidget *menu;
  GtkWidget *menuitem;
  GtkWidget *vbox;
  GtkWidget *handlebox;  
  GtkWidget *text;

    gchar *buffer = (char *) pass_strings;
              
  /*--  Initialize GTK --*/
  //gtk_init (&argc, &argv);
gtk_init (0, NULL);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  vbox = gtk_vbox_new(FALSE, 0);
  text = gtk_text_new(NULL, NULL);
  handlebox = gtk_handle_box_new();
  menubar = gtk_menu_bar_new();
  gtk_text_set_editable(GTK_TEXT (text), TRUE);
  gtk_signal_connect(GTK_OBJECT(window), "delete_event", GTK_SIGNAL_FUNC(destroyapp), NULL);

  menuFile = gtk_menu_item_new_with_label ("File");
  gtk_menu_bar_append (GTK_MENU_BAR(menubar), menuFile);
  gtk_widget_show(menuFile);
  menu = gtk_menu_new();
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(menuFile), menu);
  menuitem = gtk_menu_item_new_with_label ("New");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_widget_show (menuitem);
  menuitem = gtk_menu_item_new_with_label ("Open");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_signal_connect(GTK_OBJECT (menuitem), "activate", GTK_SIGNAL_FUNC (create_file_selection), NULL);
  gtk_widget_show (menuitem);
  menuitem = gtk_menu_item_new_with_label ("Exit");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_signal_connect(GTK_OBJECT (menuitem), "activate", GTK_SIGNAL_FUNC (ClosingAppWindow), NULL);
  gtk_widget_show (menuitem);
    
  menuEdit = gtk_menu_item_new_with_label ("Edit");
  gtk_menu_bar_append (GTK_MENU_BAR(menubar), menuEdit);
  gtk_widget_show(menuEdit);
  menu = gtk_menu_new();
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(menuEdit), menu);
  menuitem = gtk_menu_item_new_with_label ("Undo");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_widget_show (menuitem);
  menuitem = gtk_menu_item_new_with_label ("Copy");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_widget_show (menuitem);
  menuitem = gtk_menu_item_new_with_label ("Cut");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_widget_show (menuitem);
    
  menuHelp = gtk_menu_item_new_with_label ("Help");
  gtk_menu_bar_append (GTK_MENU_BAR(menubar), menuHelp);
  gtk_widget_show(menuHelp);
  menu = gtk_menu_new();
  gtk_menu_item_set_submenu(GTK_MENU_ITEM(menuHelp), menu);
  menuitem = gtk_menu_item_new_with_label ("About");
  gtk_menu_append(GTK_MENU(menu), menuitem);
  gtk_widget_show (menuitem);
    
  gtk_container_add(GTK_CONTAINER(handlebox), menubar);
  gtk_box_pack_start(GTK_BOX(vbox), handlebox, FALSE, TRUE, 0);    
  gtk_container_add(GTK_CONTAINER(vbox), text);  
  gtk_container_add(GTK_CONTAINER(window), vbox);
  gtk_text_insert(GTK_TEXT(text), NULL, NULL, NULL, buffer, strlen(buffer));
  gtk_container_border_width (GTK_CONTAINER (window), 0);
  gtk_window_set_default_size (GTK_WINDOW(window), 640, 200);
  gtk_window_set_title(GTK_WINDOW (window), "File Dialog");

  gtk_widget_show(handlebox);
  gtk_widget_show(vbox);
  gtk_widget_show(text);
  gtk_widget_show(menuitem);
  gtk_widget_show(menubar);      
  gtk_widget_show(window);

    gtk_main();
    
    /*-- Return 0 if exit is successful --*/
    //return 0;
    
   char *todest = pass_strings;

   return todest;
}

note :: is it the correct way to do "gtk_init (0, NULL);" as shown above ??

main.c

#include<stdio.h>
#include<string.h>
#include "callgtk02.h"

int main ()
{
printf("\n\nget from gtk  =  %s\n\n",call_gtk02("strings from there ...\n"));
}

this is how i compile ::

gcc `pkg-config --cflags --libs gtk` callgtk02.h -c callgtk02.c
gcc `pkg-config --cflags --libs gtk` -shared -o libcallgtk02.so callgtk02.o
gcc `pkg-config --cflags --libs gtk` -lcallgtk02 -o main main.c
./main

i link the resulting .so library to "/usr/local/lib" and run "ldconfig"

hint and guide me if found redundancies and mistakes ...


//thanks in advance


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