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Execute a terminal command from a Cocoa app
...andle *file = pipe.fileHandleForReading;
NSTask *task = [[NSTask alloc] init];
task.launchPath = @"/usr/bin/grep";
task.arguments = @[@"foo", @"bar.txt"];
task.standardOutput = pipe;
[task launch];
NSData *data = [file readDataToEndOfFile];
[file closeFile];
NSString *grepOutput = [[NSString all...
Split value from one field to two
...bername which contains both the last name and the first name of users. Is it possible to split those into 2 fields memberfirst , memberlast ?
...
Using emit vs calling a signal as if it's a regular function in Qt
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emit is just syntactic sugar. If you look at the pre-processed output of function that emits a signal, you'll see emit is just gone.
The "magic" happens in the generated code for the signal emitting function, which you can loo...
How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
...ey) DO UPDATE (and ON CONFLICT (key) DO NOTHING), i.e. upsert.
Comparison with ON DUPLICATE KEY UPDATE.
Quick explanation.
For usage see the manual - specifically the conflict_action clause in the syntax diagram, and the explanatory text.
Unlike the solutions for 9.4 and older that are given below, ...
what's data-reactid attribute in html?
...d attribute is a custom attribute used so that React can uniquely identify its components within the DOM.
This is important because React applications can be rendered at the server as well as the client. Internally React builds up a representation of references to the DOM nodes that make up your ap...
Listing all permutations of a string/integer
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First of all: it smells like recursion of course!
Since you also wanted to know the principle, I did my best to explain it human language. I think recursion is very easy most of the times. You only have to grasp two steps:
The first step
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Java URL encoding of query string parameters
...that spaces in query parameters are represented by +, not %20, which is legitimately valid. The %20 is usually to be used to represent spaces in URI itself (the part before the URI-query string separator character ?), not in query string (the part after ?).
Also note that there are three encode() me...
Bash tool to get nth line from a file
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head and pipe with tail will be slow for a huge file. I would suggest sed like this:
sed 'NUMq;d' file
Where NUM is the number of the line you want to print; so, for example, sed '10q;d' file to print the 10th line of file.
Explanation:...
A free tool to check C/C++ source code against a set of coding standards? [closed]
It looks quite easy to find such a tool for Java ( Checkstyle , JCSC ), but I can't seem to find one for C/C++. I am not looking for a lint-like static code analyzer, I only would like to check against coding standards like variable naming, capitalization, spacing, identation, bracket placement, an...
java.util.regex - importance of Pattern.compile()?
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The compile() method is always called at some point; it's the only way to create a Pattern object. So the question is really, why should you call it explicitly? One reason is that you need a reference to the Matcher object so you can use its methods, like group(int) to retrie...