[REBOL] Re: help with GetTimezoneInformation needed ...
From: antonr::lexicon::net at: 13-Mar-2005 23:36
Well, one thing I noticed is that Standard name is an array
WCHARs, not chars. WCHAR is defined in winnt.h:
typedef unsigned short wchar_t;
typedef wchar_t WCHAR;
So it is a fixed size (32 elements) array of shorts (16bits each).
You can't just specify a rebol string! in the structure.
(That's essentially just a pointer -> 4bytes)
So your structure is not big enough.
Afterwards you also have to convert the wchar array back to a string.
This will show you how I've done it.
I've got the routine doing filling the structure correctly, but
I am not giving you all the code necessary to print it all out :) yet...
(See bottom for code)
> I am trying to find out if red-icon-problem of IOS is caused by Rebol
> incorrectly interpreting timezone info or it is OS who does it in
> strange way, but I would need following routine to function :-) Sadly
> enough, I get crashes ....
> It survives the function call, but I can't touch structure, or I get
> crash ...
lib: load/library %kernel32.dll
if error? set/any 'err try [
personalize: func ["personalises the element names in a struct spec"
blk [block!] "A struct spec."
name [word! string!] "Root name for each element. This will be prefixed to
result: copy blk
if blk/1 = [save] [result: next result]
forskip result 2 [result/1: to-word rejoin [name "_" result/1]]
C-array-to-struct-spec: func ["Creates a struct spec to hold n values of
type [word!] "datatype"
name [word!] "root name for each element, eg. 'name -> name, name1, name2
len [integer!] "length of the array"
/save "Insert [save] to prevent the struct from being garbage collected."
blk: copy 
if save [insert/only blk [save]]
repeat n len [append blk compose/deep [(to-word either n = 1 [name][join
name n - 1]) [(type)]]]
;;blk: make struct! blk none
_SYSTEMTIME: [ ; struct! specification
_TIME_ZONE_INFORMATION: compose [
Bias [long] ; difference, in minutes, between UTC and local time
(C-array-to-struct-spec 'short 'StandardName 32) ;WCHAR;
(personalize _SYSTEMTIME 'StandardDate) ;SYSTEMTIME; transition from
Daylight Savings to Standard time
StandardBias [long] ; usually always zero
(C-array-to-struct-spec 'short 'DaylightName 32) ;WCHAR;
(personalize _SYSTEMTIME 'DaylightDate) ;SYSTEMTIME; transition from
Standard time to Daylight Savings
DaylightBias [long] ; added to Bias to form the bias (in minutes) used
during daylight savings. Usually -60.
;new-line/all/skip _TIME_ZONE_INFORMATION true 2
tz-info: make struct! _TIME_ZONE_INFORMATION none
;dump-memory get-struct-address tz-info ((size-of-struct? first tz-info) /
GetTimeZoneInformation: make routine! compose/deep [
LPTIME_ZONE_INFORMATION [struct! [(_TIME_ZONE_INFORMATION)]]
return: [long] ; DWORD (unsigned long)
] lib "GetTimeZoneInformation"
result: GetTimeZoneInformation tz-info
"GetTimeZoneInformation returned:" mold result select [
foreach type [Standard Daylight][
word: to-word join type "Name"
print rejoin [
word ": " wchar-array-to-string (get-struct-address tz-info)
+ (get-struct-element-offset tz-info word) 32
foreach granularity [Year Month Day DayOfWeek Hour Minute Second][
word: to-word rejoin [type "Date_" granularity]
print rejoin [
word ": " do to-path reduce ['tz-info word]
print rejoin [word: to-word join type "Bias" ": " do to-path reduce
;print mold disarm err