uniqueidentifier

I have been using the following method for around a month with no problem. The device ID remained the same even after uninstalls of the app. Recently I noticed that my device ID changed. I have been doing a lot of builds of the app recently on Xcode6. Could this be a cause? I wish I knew exactly when it changed. It caught me by surprise. Do I have anything to worry about when the app goes on the app store? Maybe this is just an Xcode build problem? I am just looking for a simple way to guarantee a unique device ID. I would use advertisingIdentifer but I hear using it for purpose other then

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 have any noise sources of predictable characteristics; the ADC is connected to a number of relatively

I need to get the hardware serial code of Android device where my app is installed. This hardware serial number is the one that you can see on Settings > About Device > Status > Serial number . I though I would get it using Settings.Secure.ANDROID_ID or android.os.Build.SERIAL , but neither of them worked, meaning that they didn't give me unique identifier I'm looking for. For instance android.os.Build.SERIAL got me the unique ID shown on ADB when you run the command adb devices . Notice that the goal of this question is not to find another unique identifier that could help me, it's only about

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 browser...? Thanks. Well after further research, the answer is: No, it's not possible right now to get

What can be the best algorithm to generate a unique id in C++? The length ID should be a 32 bit unsigned integer. 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 need a file. If it is multiple threads in one process then you need a file and a mutex. If is multiple

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 :( Nandakumar R 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 uuidRef = CFUUIDCreate(NULL); CFStringRef uuidStringRef = CFUUIDCreateString(NULL, uuidRef);

i came across the need to cleanse some data, and i need to find some particular guids (i.e. uniqueidentifiers ) in SQL Server°. i've come up with a stored procedure that does a SELECT from every uniqueidentifier column in every table in the current database, and returns a result set if the guid is found. It uses the INFORMATION_SCHEMA views to find all uniqueidentifier columns in all base tables (as opposed to views). For each column it issues a select, returning the name of the table and the column where it was found. CREATE PROCEDURE dbo.FindGUID @searchValue uniqueidentifier AS /* Search

I am using rand() for a 6 digit field which needs unique values. Am I doing it right? What are the odds, rand() can give me similar values on consecutive or frequent calls? It was unique when I used rand(). But, returned same number when I called srand(time(NULL)) or srand(clock()) . Seems, like it's working opposite for me. Or is it? As others have pointed out, uniqueness is not guaranteed. However you are probably seeing repeated numbers because you are using srand() and rand() incorrectly. srand() is used to seed the random number generator. that means a series of calls to rand() after a

What is the best way to generate a unique ID in java. People generally use String id = System.currentTimeMillis+ someStaticCounter; But this approach would require synchronization in multithreaded applications. I am using try { Thread.sleep(1); //This sleep ensures that two consecutive calls from the same thread does not return the same id. } catch (InterruptedException e) { // do nothing; } id = System.currentTimeMillis() + "-" + Thread.currentThread().getId(); This approach helps me from synchronisation overheads.. Is there any better approach please suggest? How about UUID: http://java.sun