Re: g_str_is_ascii()

["David Necas (Yeti)" <yeti physics muni cz>]

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.

Yeti


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