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How to drop unique in MySQL?
...swered Oct 14 '09 at 8:12
Wael DalloulWael Dalloul
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Is it alright to use target=“_blank” in HTML5?
I recall reading somewhere that in HTML5 it was no longer okay to use target="_blank" in HTML5, but I can't find it now.
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Example for boost shared_mutex (multiple reads/one write)?
I have a multithreaded app that has to read some data often, and occasionally that data is updated. Right now a mutex keeps access to that data safe, but it's expensive because I would like multiple threads to be able to read simultaneously, and only lock them out when an update is needed (the updat...
Why does the MongoDB Java driver use a random number generator in a conditional?
...k && Math.random() <= 0.1)
return res;
The commit that originally introduced this logic had
if (_ok == true) {
_logger.log( Level.WARNING , "Server seen down: " + _addr, e );
} else if (Math.random() < 0.1) {
_logger.log( Level.WARNING , "Server seen down: " + _addr );
}
—a...
Allowed characters in Linux environment variable names
What characters are allowed in Linux environment variable names? My cursory search of man pages and the web did only produce information about how to work with variables, but not which names are allowed.
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Detect when browser receives file download
I have a page that allows the user to download a dynamically-generated file. It takes a long time to generate, so I'd like to show a "waiting" indicator. The problem is, I can't figure out how to detect when the browser has received the file, so I can hide the indicator.
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Delete directory with files in it?
I wonder, what's the easiest way to delete a directory with all its files in it?
33 Answers
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How do you access the matched groups in a JavaScript regular expression?
...not very intuitive. This lead to the proposal of the String.prototype.matchAll method. This new method is expected to ship in the ECMAScript 2020 specification. It gives us a clean API and solves multiple problems. It has been started to land on major browsers and JS engines as Chrome 73+ / Node 12+...
When are you supposed to use escape instead of encodeURI / encodeURIComponent?
... section B.2.1.2 escape and the introduction text of Annex B says:
... All of the language features and behaviours specified in this annex have one or more undesirable characteristics and in the absence of legacy usage would be removed from this specification. ...
... Programmers should not us...
C library function to perform sort
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qsort() is the function you're looking for. You call it with a pointer to your array of data, the number of elements in that array, the size of each element and a comparison function.
It does its magic and your array is sorted in-place. An example follows:
#include <st...