-lgtk-x11-2.0: No such file or directory - c++

Question

I am trying to compile a gtk example program, but I am getting this compilation error:
gcc: error: -lgtk-x11-2.0: No such file or directory
this is the command I am using to compile:
gcc -Wall -g helloworld.c -o helloworld `pkg-config --cflags gtk+-2.0` \ `pkg-config --libs gtk+-2.0`
and this is my code (it is from this site https://developer.gnome.org/gtk-tutorial/2.90/c39.html):
#include <gtk/gtk.h>
/* This is a callback function. The data arguments are ignored
* in this example. More on callbacks below. */
static void hello( GtkWidget *widget,
gpointer data )
{
g_print ("Hello World\n");
}
static gboolean delete_event( GtkWidget *widget,
GdkEvent *event,
gpointer data )
{
/* If you return FALSE in the "delete-event" signal handler,
* GTK will emit the "destroy" signal. Returning TRUE means
* you don't want the window to be destroyed.
* This is useful for popping up 'are you sure you want to quit?'
* type dialogs. */
g_print ("delete event occurred\n");
/* Change TRUE to FALSE and the main window will be destroyed with
* a "delete-event". */
return TRUE;
}
/* Another callback */
static void destroy( GtkWidget *widget,
gpointer data )
{
gtk_main_quit ();
}
int main( int argc,
char *argv[] )
{
/* GtkWidget is the storage type for widgets */
GtkWidget *window;
GtkWidget *button;
/* This is called in all GTK applications. Arguments are parsed
* from the command line and are returned to the application. */
gtk_init (&argc, &argv);
/* create a new window */
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
/* When the window is given the "delete-event" signal (this is given
* by the window manager, usually by the "close" option, or on the
* titlebar), we ask it to call the delete_event () function
* as defined above. The data passed to the callback
* function is NULL and is ignored in the callback function. */
g_signal_connect (window, "delete-event",
G_CALLBACK (delete_event), NULL);
/* Here we connect the "destroy" event to a signal handler.
* This event occurs when we call gtk_widget_destroy() on the window,
* or if we return FALSE in the "delete-event" callback. */
g_signal_connect (window, "destroy",
G_CALLBACK (destroy), NULL);
/* Sets the border width of the window. */
gtk_container_set_border_width (GTK_CONTAINER (window), 10);
/* Creates a new button with the label "Hello World". */
button = gtk_button_new_with_label ("Hello World");
/* When the button receives the "clicked" signal, it will call the
* function hello() passing it NULL as its argument. The hello()
* function is defined above. */
g_signal_connect (button, "clicked",
G_CALLBACK (hello), NULL);
/* This will cause the window to be destroyed by calling
* gtk_widget_destroy(window) when "clicked". Again, the destroy
* signal could come from here, or the window manager. */
g_signal_connect_swapped (button, "clicked",
G_CALLBACK (gtk_widget_destroy),
window);
/* This packs the button into the window (a gtk container). */
gtk_container_add (GTK_CONTAINER (window), button);
/* The final step is to display this newly created widget. */
gtk_widget_show (button);
/* and the window */
gtk_widget_show (window);
/* All GTK applications must have a gtk_main(). Control ends here
* and waits for an event to occur (like a key press or
* mouse event). */
gtk_main ();
return 0;
}

Answer 1

The backslash before the second call to pkg-config is adding a space at the beginning of the argument. Remove it.
gcc: error: -lgtk-x11-2.0: No such file or directory
^