Re: g_str_is_ascii()

["Brian J. Tarricone" <bjt23 cornell edu>]

David Necas (Yeti) wrote:

> On Thu, May 19, 2005 at 06:18:44PM -0400, Claudio Saavedra wrote:
>  
>
> > I need to write a function to reject strings that are utf-8, i.e. accept
> > only convencional ascii strings.
> >
> > I was wondering if there is any other way more nice than making a 
> >
> > gboolean
> > str_is_ascii (const gchar *str)
> > {     
> >      return (str (mystring) == g_utf8_strlen (str, -1));
> >    
>            I suppose this should read strlen(str)
>  
>
> > }
> >    
>
> Beside being incorrect -- result of g_utf8_strlen() on
> a string that is not valid utf8 is not defined -- this is
> quite a waste of resources.
>
>    while (*str) {
>       if ((guchar)*str >= 128)
>           return FALSE;
>    }
>    return TRUE;
>
> does the latter: accept only ASCII strings.  It does not do
> the former (reject valid UTF-8), except when you know the
> string is valid UTF-8 and only need to check whether it is
> valid ASCII too, in this case the two checks conincide.
Aside from the fact that this gives you an infinite loop if the first
character is ASCII... might want to stick a 'str++' somewhere in there ^_~.

    -brian