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Getting MAC Address

... says that it will return a random long if it fails to detect the mac: "If all attempts to obtain the hardware address fail, we choose a random 48-bit number with its eighth bit set to 1 as recommended in RFC 4122." So check that eighth bit! – deinonychusaur Fe...
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How do you delete an ActiveRecord object?

... It's destroy and destroy_all methods, like user.destroy User.find(15).destroy User.destroy(15) User.where(age: 20).destroy_all User.destroy_all(age: 20) Alternatively you can use delete and delete_all which won't enforce :before_destroy and :after...
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Python Logging (function name, file name, line number) using a single file

...line number (within the code) where I send a message to the log output. Finally, since this application comprises of many files, I want to create a single log file so that I can better understand the control flow of the application. ...
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AngularJS HTTP post to PHP and undefined

...send that as data. Make sure that this query string is URL encoded. If manually built (as opposed to using something like jQuery.serialize()), Javascript's encodeURIComponent() should do the trick for you. share | ...
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What are the rules about using an underscore in a C++ identifier?

...FC background, you'll probably use m_foo . I've also seen myFoo occasionally. 5 Answers ...
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Linq to Sql: Multiple left outer joins

... This may be cleaner (you dont need all the into statements): var query = from order in dc.Orders from vendor in dc.Vendors .Where(v => v.Id == order.VendorId) .DefaultIfEmpty() from status in dc.Status .Where(...
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How to find the width of a div using vanilla JavaScript?

... All Answers are right, but i still want to give some other alternatives that may work. If you are looking for the assigned width (ignoring padding, margin and so on) you could use. getComputedStyle(element).width; //returns...
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Finding a substring within a list in Python [duplicate]

... All the answers work but they always traverse the whole list. If I understand your question, you only need the first match. So you don't have to consider the rest of the list if you found your first match: mylist = ['abc123'...
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Why does GCC generate such radically different assembly for nearly the same C code?

...e(). I'll spare you the assembly, but it is identical - register names and all. Step 2: Mathematical reduction: x + (y ^ x) = y sign can only take one of two values, 0 or 0x80000000. When x = 0, then x + (y ^ x) = y then trivial holds. Adding and xoring by 0x80000000 is the same. It flips the sign...
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mongodb group values by multiple fields

... $slice just off the basic aggregation result. For "large" results, run parallel queries instead for each grouping ( a demonstration listing is at the end of the answer ), or wait for SERVER-9377 to resolve, which would allow a "limit" to the number of items to $push to an array. db.books.aggregate(...