one question about glib

["Leao" <jinmu190 163 com>]

Hello, List!
Recently, I am writing a little program with gtk+ on win32 platform. In this program I use 
g_spawn_async_with_pipes(NULL,cmd_line,NULL,G_SPAWN_SEARCH_PATH,NULL,NULL,NULL,NULL,&std_out,NULL,NULL); to 
call gcc and as a result the command line has executed successfully .However when I use 
g_io_channel_reda_chars(channel,out,-1,&bytes_read,NULL) to get the standard out stored in out, it turns out 
to be wrong.Here is my code :

   gchar *cmd_line[] = {"gcc","-o","temp.exe","temp.c","-mms-bitfields", "-lgtk-win32-2.0", 
"-lgdk-win32-2.0", "-latk-1.0", "-lgdk_pixbuf-2.0", "-lpangowin32-1.0", "-lgdi32" ,"-lpango-1.0" 
,"-lgobject-2.0" ,"-lgmodule-2.0", "-lglib-2.0" ,"-lintl"};
    gchar out[1024];
    GIOChannel *channel;
    gint std_out = 0;
    gint bytes_read;        
g_spawn_async_with_pipes(NULL,cmd_line,NULL,G_SPAWN_SEARCH_PATH,NULL,NULL,NULL,NULL,&std_out,NULL,NULL);
    channel = g_io_channel_unix_new(std_out);
    g_io_channel_read_chars(channel,out,-1,&bytes_read,NULL);

If I want to get the standard out ,what should I do?
 Any info is appreciated ! :)