Depending on your kernel, the DMI information may be available via sysfs. Try those: # cat /sys/class/dmi/id/board_serial xxxxxxxxxxxxxxx # cat /sys/class/dmi/id/product_uuid xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx or using a tool # dmidecode -s baseboard-serial-number … # dmidecode -s system-uuid …
Are serial numbers of NFC tags truely unique? That depends on the tag product and what you consider truely unique. E.g.: ISO 14443 Type A tags with 4 byte serial numbers: There certainly exist duplicates (mainly because there is no clear scheme to divide the available range of serial numbers among the various manufacturers) and … Read more
Create your own file name: CFUUIDRef uuid = CFUUIDCreate(NULL); CFStringRef uuidString = CFUUIDCreateString(NULL, uuid); CFRelease(uuid); NSString *uniqueFileName = [NSString stringWithFormat:@”%@%@”, prefixString, (NSString *)uuidString]; CFRelease(uuidString); A simpler alternative proposed by @darrinm in the comments: NSString *prefixString = @”MyFilename”; NSString *guid = [[NSProcessInfo processInfo] globallyUniqueString] ; NSString *uniqueFileName = [NSString stringWithFormat:@”%@_%@”, prefixString, guid]; NSLog(@”uniqueFileName: ‘%@'”, uniqueFileName); NSLog … Read more
In My case it was ibGoogleAnalytics_debug.a library. To find which library is using uniqueidentifier method, go to your project folder and type in: $ find . | grep -v .svn | grep “\.a” | grep -v “\.app” | xargs grep uniqueIdentifier I got this: Binary file ./My_Project/libGoogleAnalytics_debug.a matches
Just cast it as a BINARY(16). SELECT category, MIN(CAST(guid AS BINARY(16))) FROM myTable GROUP BY category You can cast it back later if necessary. WITH CategoryValue AS ( SELECT category, MIN(CAST(guid AS BINARY(16))) FROM myTable GROUP BY category ) SELECT category, CAST(guid AS UNIQUEIDENTIFIER) FROM CategoryValue
What you are looking for is called Browser Fingerprinting. You can google for some open source libraries. Ex: fingerprintjs2 Check out EFF’s demo
As selected answer says you can use findAndModify to generate sequential IDs. But I strongly disagree with opinion that you should not do that. It all depends on your business needs. Having 12-byte ID may be very resource consuming and cause significant scalability issues in future. I have detailed answer here.
Taking into consideration that my application targets Android 4.0 (API 14) and above, is the android.os.Build.SERIAL number for the android devices unique for each device ? According to this useful article in the Android Developers blog, android.os.Build.SERIAL should be unique if it is available. From the article: Devices without telephony are required to report a … Read more
just mask the 128bit int >>> import uuid >>> uuid.uuid4().int & (1<<64)-1 9518405196747027403L >>> uuid.uuid4().int & (1<<64)-1 12558137269921983654L These are more or less random, so you have a tiny chance of a collision Perhaps the first 64 bits of uuid1 is safer to use >>> uuid.uuid1().int>>64 9392468011745350111L >>> uuid.uuid1().int>>64 9407757923520418271L >>> uuid.uuid1().int>>64 9418928317413528031L These are … Read more
Make a small function that returns random letters for a given length: <?php function generate_random_letters($length) { $random = ”; for ($i = 0; $i < $length; $i++) { $random .= chr(rand(ord(‘a’), ord(‘z’))); } return $random; } Then you’ll want to call that until it’s unique, in pseudo-code depending on where you’d store that information: do … Read more