if (!dir1 || !dir2) return FALSE;
static XP_Bool vr_CompareDirs( char *dir1, char *dir2 ){    int len1,len2;    len1 = XP_STRLEN( dir1 );    len2 = XP_STRLEN( dir2 );    if ( dir1[len1-1] == VR_FILE_SEP )        len1--;    if ( dir2[len2-1] == VR_FILE_SEP )        len2--;    if ( len1 != len2 )        return FALSE;#ifdef XP_UNIX    return ( XP_STRNCMP(dir1, dir2, len1) == 0 );#else    return ( XP_STRNCASECMP(dir1, dir2, len1) == 0 );#endif}