compile gtk with libcurl

[Rudra Banerjee <bnrj rudra yahoo com>]

Friends,
Please check the program:
#include <stdio.h>
#include <gtk/gtk.h>
#include <gdk/gdk.h>

#include <curl/curl.h>

GtkWidget *Bar;

size_t my_write_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
  return fwrite(ptr, size, nmemb, stream);
}

size_t my_read_func(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
  return fread(ptr, size, nmemb, stream);
}

int my_progress_func(GtkWidget *bar,
                     double t, /* dltotal */
                     double d, /* dlnow */
                     double ultotal,
                     double ulnow)
{
/*  printf("%d / %d (%g %%)\n", d, t, d*100.0/t);*/
  gdk_threads_enter();
  gtk_progress_set_value(GTK_PROGRESS(bar), d*100.0/t);
  gdk_threads_leave();
  return 0;
}

void *my_thread(void *ptr)
{
  CURL *curl;
  CURLcode res;
  FILE *outfile;
  gchar *url = ptr;

  curl = curl_easy_init();
  if(curl)
  {
    outfile = fopen("test.curl", "w");

    curl_easy_setopt(curl, CURLOPT_URL, url);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, outfile);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, my_write_func);
    curl_easy_setopt(curl, CURLOPT_READFUNCTION, my_read_func);
    curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
    curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, my_progress_func);
    curl_easy_setopt(curl, CURLOPT_PROGRESSDATA, Bar);

    res = curl_easy_perform(curl);

    fclose(outfile);
    /* always cleanup */
    curl_easy_cleanup(curl);
  }

  return NULL;
}

int main(int argc, char **argv)
{
  GtkWidget *Window, *Frame, *Frame2;
  GtkAdjustment *adj;

  /* Must initialize libcurl before any threads are started */
  curl_global_init(CURL_GLOBAL_ALL);

  /* Init thread */
  g_thread_init(NULL);

  gtk_init(&argc, &argv);
  Window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  Frame = gtk_frame_new(NULL);
  gtk_frame_set_shadow_type(GTK_FRAME(Frame), GTK_SHADOW_OUT);
  gtk_container_add(GTK_CONTAINER(Window), Frame);
  Frame2 = gtk_frame_new(NULL);
  gtk_frame_set_shadow_type(GTK_FRAME(Frame2), GTK_SHADOW_IN);
  gtk_container_add(GTK_CONTAINER(Frame), Frame2);
  gtk_container_set_border_width(GTK_CONTAINER(Frame2), 5);
  adj = (GtkAdjustment*)gtk_adjustment_new(0, 0, 100, 0, 0, 0);
  Bar = gtk_progress_bar_new_with_adjustment(adj);
  gtk_container_add(GTK_CONTAINER(Frame2), Bar);
  gtk_widget_show_all(Window);

  if (!g_thread_create(&my_thread, argv[1], FALSE, NULL) != 0)
    g_warning("can't create the thread");


  gdk_threads_enter();
  gtk_main();
  gdk_threads_leave();
  return 0;
}


This is a program from libcurl. I posted in there forum and they said
its better to post here.
When I tried to compile it, I found the error:
$ gcc curlgtk.c -o cpan  `pkg-config --cflags gtk+-2.0` `pkg-config
--libs libcurl gtk+-2.0`
/usr/bin/ld: /tmp/ccZN7P8Q.o: undefined reference to symbol
'g_thread_init'
/usr/bin/ld: note: 'g_thread_init' is defined in
DSO /lib64/libgthread-2.0.so.0 so try adding it to the linker command
line
/lib64/libgthread-2.0.so.0: could not read symbols: Invalid operation

I also tried the suggestion from
https://bbs.archlinux.org/viewtopic.php?id=106212

and now the error is 
gcc curlgtk.c $(pkg-config --libs --cflags gtk+-2.0 librl)
/usr/bin/ld: /tmp/ccfvzrCv.o: undefined reference to symbol
'g_thread_init'
/usr/bin/ld: note: 'g_thread_init' is defined in
DSO /lib64/libgthread-2.0.so.0 so try adding it to the linker command
line
/lib64/libgthread-2.0.so.0: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status

Where I am going wrong?