Hi,
Can you guys show me how to get and set the windows system time and date?
Is this "time(time_t long_time)" a function to get the windows time and date?
How about set time and date?
Please help.
Thanks!!
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Hi,
Can you guys show me how to get and set the windows system time and date?
Is this "time(time_t long_time)" a function to get the windows time and date?
How about set time and date?
Please help.
Thanks!!
To change the actual time in the system, you need to use SetSystemTime.
--
Mats
If I am using SetSystemTime and GetSystemTime, I must include <windows.h> right?
But I have this compilation error:->
C:\Program Files\Microsoft Visual Studio\VC98\INCLUDE\basetsd.h(33) : error C2371: 'INT32' : redefinition; different basic types
Q:/code/common/std_types.h(68) : see declaration of 'INT32'
In std_types.h:-
typedef int32_t INT32;
In basetsd.h:-
typedef int INT32, *PINT32;
How to solve this?
Please help!
Thanks a lot!!
I expect that q:/code/common/std_types.h is not a standard file. Who supplied this file?
INT32 should be defined once, in one place... Although it may of course not be easy to achieve. Also, int32_t is not a standard MS type, as far as I know (it bears resemblance to Linux types - unless I'm confusing myself).
The other option is to completely isolate the inclusion of windows.h in a separate source file that doesn't include std_types.h. However, this brings a problem of what you pass between this function and the main code that DOES include std_types.h - you can of course rely on INT32 in the two different files, whilst using different methods, achieve the same thing, and thus just use "whichever is present" in a separate header file. But you do have a possible conflict here.
A third option is to include basetsd.h [or the parent of that file] in std_types.h, and remove any conflicts from std_types.h - this of course assumes that std_types.h is "yours to modify".
--
Mats
Yeah! std_types.h is a self-defined header file and it must not be excluded.
Meaning that I must include std_types.h in my program and I am not allowed to modify this file.
Is there any other ways to get and set the system time and date if I am not going to use GetSystemTime and SetSystemTime from "windows.h"?
I am working on C++ Program.
Please help.
Thanks!
You could try using the Windows console command 'Time'.
May require you to call 'system' or create a console window with CreateProcess() (depending on your app)
http://technet.microsoft.com/en-au/l.../bb491015.aspx
That is completely silly. If you NEED to use windows.h, but some other file interferes with it, then you MUST raise a bug report on that component - it is broken, and you should not have such a situation. Defining your own symbols that are different from the standard ones supplied by Windows is just not right - you can have your own ones with different names, that's fine.Quote:
Originally Posted by huwan
If you don't know what to do, just point out to your project manager (or whoever) that you can't actually do your job because of this.
There may be other ways to solve the problem, but what happens when you come to the next situation where you need to use windows.h, and there happens to be no alternative?
--
Mats
Yeah very silly!!
Besides of SetSystemTime and GetSystemTime, are there any other c++ functions that can be used to get and set the system time?I mean alternative method.
I have no choice! Might have to kick away SetSystemTime and GetSystemTime functions!
There is no standard way of setting the system time, and I'm not aware of any Visual Studio interface that translates to SetSystemTime at a lower level. The GetSystemTime can be replaced with time() and it's related functions, if you wish.Quote:
Originally Posted by huwan
--
Mats
I have tried with time() but somehow the compilation failed.
It says "struct tm" and time() are undefined.
I have included "time.h" but not sure why it failed.
how about "settimeofday" and "gettimeofday"?
Can I use these functions in my c++ program?
Those are Linux(or Posix?) functions - they do not work in Windows. But from a C++ standpoint, if you have a library with such a function, C++ will allow you to use it.Quote:
Originally Posted by huwan
Note that the C and C++ languages as such do not require there being any form of time in the system. Most OS's do support some form of timing, because programmers frequently wish for such things, but the language leaves it to the standard library and OS vendor to sort out how to implement the access of the time.
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Mats
Argghh!! sigh...what can I do?
I have been searching around and trying with different functions but none of them is working.
I have already suggested that you put the SetSystemTime function in a separate (OS architecture dependant) file.Quote:
Originally Posted by huwan
The other option is of course that you don't mess with the system time. That would also be a sensible thing to do.
Edit: Another option is of course that you use some external library - but I couldn't find anything in the Boost library, which is otherwise a common place to find OS independent solutions of this type.
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Mats
Boost has the DateTime library, but it doesn't allow setting the time.
What you have here are absurd conflicting requirements. I still think that changing std_types.h is the correct thing to do. It sounds like this is some course assignment, though, and teachers can be stubborn.
You could also declare just the API functions you need. The undecorated prototypes of GetSystemTime and SetSystemTime are:
Code:extern "C"
{
struct SYSTEMTIME
{
unsigned short wYear;
unsigned short wMonth;
unsigned short wDayOfWeek;
unsigned short wDay;
unsigned short wHour;
unsigned short wMinute;
unsigned short wSecond;
unsigned short wMilliseconds;
};
void __stdcall GetSystemTime(SYSTEMTIME *pSystemTime);
int __stdcall SetSystemTime(const SYSTEMTIME *pSystemTime);
}
That _IS_ a solution, I did consider it, but thought it "ugly enough" that I didn't want to suggest that. One consequence is that IF at any time, Get/SetSystemTime's interface is modified [unlikely, I know], it will not cause any compile time problem, but rather a run-time problem. It is also subject to compiler wide settings for alignment within structs, which is normally well defined by the Windows.hQuote:
Originally Posted by CornedBee
--
Mats
True. But I'm relying on MS not screwing themselves. Any ABI change in this function would break endless amounts of code.
The packing thing is the only problem. You can fix that by adding packing pragmas.
Code:// Before the struct:
#pragma pack(push, 1)
// After the struct:
#pragma pack(pop)
Fair enough.
However, I still think this is a poor solution - the correct thing to do would be to fix up whatever needs to be fixed to make Windows.h possible to include (at least into a separate source file).
What happens when the original poster needs another Windows function, where do you draw the limit for having your own declarations of the Windows API? 3, 5, 10 or 100 functions?
--
Mats
Of course it's a poor solution. It's a poor situation - forced to use an unmodifiable header that has a useless typedef that conflicts with windows.h.