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When to wrap quotes around a shell variable?
... quote it if it can either be empty or contain spaces (or any whitespace really) or special characters (wildcards). Not quoting strings with spaces often leads to the shell breaking apart a single argument into many.
$? doesn't need quotes since it's a numeric value. Whether $URL needs it depends o...
How do I write a for loop in bash
... doSomething($n)
done
Note the $(...) syntax. It's a bash behaviour, it allows you to pass the output from one command (in our case from seq) to another (the for)
This is really useful when you have to iterate over all directories in some path, for example:
for d in $(find $somepath -type d)
do...
Command substitution: backticks or dollar sign / paren enclosed? [duplicate]
...orm. The second form, using a pair of backquotes (the "`" character, also called a backtick and a grave accent), is the historical way of doing it. The first form, using dollar sign and parentheses, is a newer POSIX form, which means it's probably a more standard way of doing it. In turn, I'd think ...
What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... NULL is less efficient
In PostgreSQL, NOT IN is less efficient
In Oracle, all three methods are the same.
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How to wrap async function calls into a sync function in Node.js or Javascript?
...pose you maintain a library that exposes a function getData . Your users call it to get actual data:
var output = getData();
Under the hood data is saved in a file so you implemented getData using Node.js built-in fs.readFileSync . It's obvious both getData and fs.readFileSync are sync ...
Converting many 'if else' statements to a cleaner approach [duplicate]
...ng this approach you could easily add different converters in the future.
All untested, probably doesn't compile, but you get the idea
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Angular IE Caching issue for $http
All the ajax calls that are sent from the IE are cached by Angular and I get a 304 response for all the subsequent calls. Although the request is the same, the response is not going be the same in my case. I want to disable this cache. I tried adding the cache attribute to $http.get but still it...
How does a Java HashMap handle different objects with the same hash code?
...ng bucket, and then it will compare the key that you gave with the keys of all pairs in the bucket, by comparing them with equals().
Now you can see how this is very efficient for looking up key-value pairs in a map: by the hash code of the key the hashmap immediately knows in which bucket to look,...
What is meant by “managed” vs “unmanaged” resources in .NET?
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The term "unmanaged resource" is usually used to describe something not directly under the control of the garbage collector. For example, if you open a connection to a database server this will use resources on the server (for maintaining the connection) and po...
Convert String to Type in C# [duplicate]
...he type (with its namespace, of course) if the type is in mscorlib or the calling assembly. Otherwise, you've got to include the assembly name as well:
Type type = Type.GetType("Namespace.MyClass, MyAssembly");
If the assembly is strongly named, you've got to include all that information too. See...