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Is there a way to change the environment variables of another process in Unix?
...t one process can change another's environment variables (assuming they're all being run by the same user)? A general solution would be best, but if not, what about the specific case where one is a child of the other?
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I do not want to inherit the child opacity from the parent in CSS
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Opacity is not actually inherited in CSS. It's a post-rendering group transform. In other words, if a <div> has opacity set you render the div and all its kids into a temporary buffer, and then composite that whole buffer into the page ...
Why does my application spend 24% of its life doing a null check?
...t store a copy of the bytes in RAM. An important one is the L1 cache, typically 16 kilobytes for data and 16 kilobytes for instructions. Small, allowing it to be close to the execution engine. Reading bytes from the L1 cache typically takes 2 or 3 CPU cycles. Next up is the L2 cache, bigger and slow...
Why does Apple recommend to use dispatch_once for implementing the singleton pattern under ARC?
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dispatch_once() is absolutely synchronous. Not all GCD methods do things asynchronously (case in point, dispatch_sync() is synchronous). The use of dispatch_once() replaces the following idiom:
+ (MyClass *)sharedInstance {
static MyClass *sharedInstance;
@synchr...
Update R using RStudio
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You install a new version of R from the official website.
RStudio should automatically start with the new version when you relaunch it.
In case you need to do it manually, in RStudio, go to :Tools -> options -> General.
Chec...
How do you use bcrypt for hashing passwords in PHP?
...d salts (bcrypt REQUIRES salts) and you can be sure that an attack is virtually unfeasible without either ludicrous amount of funds or hardware.
bcrypt uses the Eksblowfish algorithm to hash passwords. While the encryption phase of Eksblowfish and Blowfish are exactly the same, the key schedule pha...
Are (non-void) self-closing tags valid in HTML5?
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In HTML 4, <foo / (yes, with no > at all) means <foo> (which leads to <br /> meaning <br>> (i.e. <br>&gt;) and <title/hello/ meaning <title>hello</title>). This is an SGML rule that browsers did a very poor job of su...
How to install Hibernate Tools in Eclipse?
What is the proper way to install Hibernate Tools in Eclipse as a plugin?
The Hibernate site doesn't really give any instructions.
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How many bytes does one Unicode character take?
...ing, it defines codepoints and a codepoint is a number, associated with usually a character. I say usually because there are concepts like combining characters. You may be familiar with things like accents, or umlauts. Those can be used with another character, such as an a or a u to create a new log...
Elements order in a “for (… in …)” loop
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Quoting John Resig:
Currently all major browsers loop over the properties of an object in the order in
which they were defined. Chrome does this as well, except for a couple cases. [...]
This behavior is explicitly left undefined by the ECMAScript specifi...