uniqueidentifier

sources of “uniqueness”/entropy on embedded systems

由 杀马特。学长 韩版系。学妹 提交于 2019-12-03 09:06:23
问题 I have an embedded system. What I would like for it to do when it powers up or otherwise resets, is to generate a unique ID, so that on different restarts a different unique ID is generated with high probability. It does not have access to a real-time clock, but it does have access to an ADC and a UART. I am wondering if there is a decent way to gather entropy from these sources to generate a unique ID. I am vaguely familiar with Yarrow. Is there a good way to use this? Unfortunately I do not

is it possible to get a unique identification number from a mobile device?

由 限于喜欢 提交于 2019-12-03 08:21:58
问题 I am currently working on mobile device web applications, and I was wondering if there is some sort of unique id number per device that could be detected via the browser. The purpose would be to store this number in order to recognize people who already visited the site. I was working with bluetooth quite a lot, and there some sort of mac address you can store when you detect a device, and I was using this as Id number, so that's my question, is there a general ID number I can detect from the

How to detect if any external libraries are calling [UIDevice currentDevice] uniqueIdentifier]?

由 随声附和 提交于 2019-12-03 07:28:58
So, since Apple is now rejecting apps that access UDID , on our company's current project, we need to eliminate all APIs that make a call to this property: [[UIDevice currentDevice] uniqueIdentifier] We have eliminated all the calls in our own code, but need to be sure that the many external libraries we are using are not making calls to this property. What is the most reliable method for determining if a library is calling on this property? Thank you in advance! Aside from using otx (which seems to have gotten flaky) one option is to set a symbolic breakpoint on that method and then run the

Algorithm for generating a unique ID in C++?

由 北慕城南 提交于 2019-12-03 06:38:27
问题 What can be the best algorithm to generate a unique id in C++? The length ID should be a 32 bit unsigned integer. 回答1: Getting a unique 32-bit ID is intuitively simple: the next one. Works 4 billion times. Unique for 136 years if you need one a second. The devil is in the detail: what was the previous one? You need a reliable way to persist the last used value and an atomic way to update it. How hard that will be depends on the scope of the ID. If it is one thread in one process then you only

Aggregate Function on Uniqueidentifier (GUID)

由 ￣綄美尐妖づ 提交于 2019-12-03 06:28:31
问题 Let's say I have the following table: category | guid ---------+----------------------- A | 5BC2... A | 6A1C... B | 92A2... Basically, I want to do the following SQL: SELECT category, MIN(guid) FROM myTable GROUP BY category It doesn't necessarily have to be MIN. I just want to return one GUID of each category. I don't care which one. Unfortunately, SQL Server does not allow MIN or MAX on GUIDs. Of course, I could convert the guid into a varchar, or create some nested TOP 1 SQL, but that

identifierForVendor changes on reinstall

由 心不动则不痛 提交于 2019-12-03 06:05:02
问题 identifierForVendor is not supposed to change on reinstall of app: The value in this property remains the same while the app (or another app from the same vendor) is installed on the iOS device. The value changes when the user deletes all of that vendor’s apps from the device and subsequently reinstalls one or more of them. The value can also change when installing test builds using Xcode or when installing an app on a device using ad-hoc distribution. Therefore, if your app stores the value

Generate unique ID

由 瘦欲@ 提交于 2019-12-03 05:04:35
问题 I need to generate unique ID's for my application. When I used (UUID.randomUUID()).toString() , I am getting a code (thinking this will be unique), which is very lengthy. I am not sure how unique it will be, when we generate codes with the help of Java Timestamp or randomstring. I need to generate unique codes which is only of 8-10 characters in length (alpha-numeric). How to get so? I am using MySQL database. Is generating unique code on database side is the best way or can we generate such

How to obtain the android_id of a device? [duplicate]

由 北慕城南 提交于 2019-12-03 04:46:17
This question already has answers here : Is there a unique Android device ID? (47 answers) Possible Duplicate: Is there a unique Android device ID? In the licensing documentation the android developers mention an easy way to more or less securely identify an android device. They are using android.Settings.Secure.ANDROID_ID. They say they query the system settings for this. But they don't explain this any further. How do I obtain the android_id and do I need special permissions for doing so? Christopher Orr It's all in the Javadoc, as linked to by this question you edited 30 minutes before this

How to generate a unique identifier?

由 浪尽此生 提交于 2019-12-03 04:42:59
问题 I need to generate some int value that would never repeat (at least theoretically). I know there is arc4random() fnc but I'm not sure how to use it with some current date or smth :( 回答1: This returns a unique key very similar to UUID generated in MySQL. + (NSString *)uuid { CFUUIDRef uuidRef = CFUUIDCreate(NULL); CFStringRef uuidStringRef = CFUUIDCreateString(NULL, uuidRef); CFRelease(uuidRef); return [(NSString *)uuidStringRef autorelease]; } ARC version: + (NSString *)uuid { CFUUIDRef

How to generate and manually insert a uniqueidentifier in sql server?

由 馋奶兔 提交于 2019-12-03 04:32:21
I'm trying to manually create a new user in my table but impossible to generate a "UniqueIdentifier" type without threw an exception ... Here is my example: DECLARE @id uniqueidentifier SET @id = NEWID() INSERT INTO [dbo].[aspnet_Users] ([ApplicationId] ,[UserId] ,[UserName] ,[LoweredUserName] ,[LastName] ,[FirstName] ,[IsAnonymous] ,[LastActivityDate] ,[Culture]) VALUES ('ARMS' ,@id ,'Admin' ,'admin' ,'lastname' ,'firstname' ,0 ,'2013-01-01 00:00:00' ,'en') GO Trow exception -> Msg 8169, Level 16, State 2, Line 4 Failed to convert a character string to uniqueidentifier. I use the NEWID()
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