Thread overview | |||||||
---|---|---|---|---|---|---|---|
|
January 12, 2015 casting SysTime to ubyte[] | ||||
---|---|---|---|---|
| ||||
import std.datetime; import std.stdio; import std.conv; void main(string[] arg) { auto a=Clock.currTime(); auto b=cast(ubyte[])a; writefln("%s",b); } how do i get the time as a binary representation I can write to a file? Thanks. |
January 12, 2015 Re: casting SysTime to ubyte[] | ||||
---|---|---|---|---|
| ||||
Posted in reply to Laeeth Isharc | On 1/12/15 8:59 AM, Laeeth Isharc wrote:
> import std.datetime;
> import std.stdio;
> import std.conv;
>
> void main(string[] arg)
> {
> auto a=Clock.currTime();
> auto b=cast(ubyte[])a;
> writefln("%s",b);
> }
>
> how do i get the time as a binary representation I can write to a file?
You can always cast one pointer to another without complaint:
(cast(ubyte *)&a)[0..a.sizeof];
-Steve
|
January 12, 2015 Re: casting SysTime to ubyte[] | ||||
---|---|---|---|---|
| ||||
Posted in reply to Laeeth Isharc | V Mon, 12 Jan 2015 13:59:27 +0000 Laeeth Isharc via Digitalmars-d-learn <digitalmars-d-learn@puremagic.com> napsáno: > import std.datetime; > import std.stdio; > import std.conv; > > void main(string[] arg) > { > auto a=Clock.currTime(); > auto b=cast(ubyte[])a; > writefln("%s",b); > } > > how do i get the time as a binary representation I can write to a file? > > Thanks. import std.datetime; import std.stdio; import std.conv; void main(string[] arg) { auto a=Clock.currTime(); auto b= (cast(ubyte*)&a)[0 .. a.sizeof]; writefln("%s",b); } |
January 12, 2015 Re: casting SysTime to ubyte[] | ||||
---|---|---|---|---|
| ||||
Posted in reply to Laeeth Isharc | On Monday, January 12, 2015 13:59:27 Laeeth Isharc via Digitalmars-d-learn wrote:
> import std.datetime;
> import std.stdio;
> import std.conv;
>
> void main(string[] arg)
> {
> auto a=Clock.currTime();
> auto b=cast(ubyte[])a;
> writefln("%s",b);
> }
>
> how do i get the time as a binary representation I can write to a file?
I really wouldn't advise doing that. SysTime contains a long which represents the time in hnsecs since midnight, January 1st, 1 A.D., and that could be written to a file quite easily. But it also contains a reference to a TimeZone object, so what you're doing would just be writing its address to disk, which wouldn't do you any good at all, since that's specific to each run of the program, even assuming that the object exists in both runs of the program (which it would for UTC or LocalTime but not for user-constructed time zones).
So, writing the stdTime (horrible name, I know) property to disk would work just fine (that's the hnsecs as a long), but you're going to have to do something smarter than that if you want to retain the time zone. And you're not going to want to try and simply cast a SysTime to a ubyte[] and do anything practical with that regardless.
- Jonathan M Davis
|
January 14, 2015 Re: casting SysTime to ubyte[] | ||||
---|---|---|---|---|
| ||||
Posted in reply to Jonathan M Davis |
> I really wouldn't advise doing that. SysTime contains a long which
> represents the time in hnsecs since midnight, January 1st, 1 A.D., and that
> could be written to a file quite easily. But it also contains a reference to
> a TimeZone object, so what you're doing would just be writing its address to
> disk, which wouldn't do you any good at all, since that's specific to each
> run of the program, even assuming that the object exists in both runs of the
> program (which it would for UTC or LocalTime but not for user-constructed
> time zones).
>
> So, writing the stdTime (horrible name, I know) property to disk would work
> just fine (that's the hnsecs as a long), but you're going to have to do
> something smarter than that if you want to retain the time zone. And you're
> not going to want to try and simply cast a SysTime to a ubyte[] and do
> anything practical with that regardless.
>
> - Jonathan M Davis
Thanks for this. I still with my C habits had the idea the time would just be a flat struct. So in this case better to write it as a string, which is what I have already done. I just wondered why the other approach didn't work, and now I understand.
|
Copyright © 1999-2021 by the D Language Foundation