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Using a dispatch_once singleton model in Swift
...tl;dr: Use the class constant approach if you are using Swift 1.2 or above and the nested struct approach if you need to support earlier versions.
From my experience with Swift there are three approaches to implement the Singleton pattern that support lazy initialization and thread safety.
Class c...
The written versions of the logical operators
This is the only place I've ever seen and , or and not listed as actual operators in C++. When I wrote up a test program in NetBeans, I got the red underlining as if there was a syntax error and figured the website was wrong, but it is NetBeans which is wrong because it compiled and ran as exp...
Check folder size in Bash
I'm trying to write a script that will calculate a directory size and if the size is less than 10GB, and greater then 2GB do some action. Where do I need to mention my folder name?
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iPhone Safari Web App opens links in new window
...is launched from Home Screen, all links will open in new window in Safari (and lose full screen functionality). How can I prevent it? I couldn't find any help, only the same unanswered question.
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Benefits of using the conditional ?: (ternary) operator
What are the benefits and drawbacks of the ?: operator as opposed to the standard if-else statement. The obvious ones being:
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Installing PDO driver on MySQL Linux server
...long ago, to change my code to use PDO in order to parameterize my queries and safely save HTML in the database.
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The JPA hashCode() / equals() dilemma
There have been some discussions here about JPA entities and which hashCode() / equals() implementation should be used for JPA entity classes. Most (if not all) of them depend on Hibernate, but I'd like to discuss them JPA-implementation-neutrally (I am using EclipseLink, by the way).
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How do I measure separate CPU core usage for a process?
...es shown by having that specific process run under a specific user account and use Type 'u' to limit to that user
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How does the HyperLogLog algorithm work?
I've been learning about different algorithms in my spare time recently, and one that I came across which appears to be very interesting is called the HyperLogLog algorithm - which estimates how many unique items are in a list.
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How to redirect and append both stdout and stderr to a file with Bash?
...left to right as follows:
>>file.txt: Open file.txt in append mode and redirect stdout there.
2>&1: Redirect stderr to "where stdout is currently going". In this case, that is a file opened in append mode. In other words, the &1 reuses the file descriptor which stdout currently us...