Re: g_printf_string_upper_bound and positional parameters

[Havoc Pennington <hp redhat com>]

Thomas Schultz <tststs gmx de> writes: 
> However, I now added gettext support and one of the translators (Byrial
> Jensen <byrial image dk>) complained that the code could not handle
> positional parameters.  He suggested finding out the length of a format
> string by writing it to the null device instead, like this:
> 
> int printf_string_length (const char *format, va_list args)
> {
>    static FILE *null;
> 
>    if (!null)
>    {
>       null = fopen ("/dev/null", "w");
>       if (!null)
>          return -1; /* Add some error handling */
>    }
>    return vfprintf (null, format, args);
>    /* Leave null open. */
> }
> 
> To me, this sounds like a workable solution, but I guess there must be a
> reason why it isn't done this way in glib.  Any hints?

 - slow
 - not portable to non-UNIX
 - does unexpected I/O

Havoc