static const char * strlwc(const char * in, char *out, unsigned len)
{
    unsigned i ;

    if (in==NULL || out == NULL || len==0) return NULL ;
    i=0 ;
    while (in[i] != '\0' && i < len-1) {
        out[i] = (char)tolower((int)in[i]);
        i++ ;
    }
    out[i] = '\0';
    return out ;
}
static const char * strlwc(const char * in, char *out, unsigned len)
{
    unsigned i ;

    if (in==NULL || out == NULL || len==0) return NULL ;
    i=0 ;
    while (in[i] != '\0' && i < len-1) {
        out[i] = (char)tolower((int)in[i]);
        i++ ;
    }
    out[i] = '\0';
    return out ;
}