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Is there a simple, elegant way to define singletons? [duplicate]
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I don't really see the need, as a module with functions (and not a class) would serve well as a singleton. All its variables would be bound to the module, which could not be instantiated repeatedly anyway.
If you do wish to use a class, there is no way of creating private classes...
TSQL Pivot without aggregate function
...er that DBColumnName is metadata - you literally filter by "CustomerID = 1 AND DBColumnName = 'FirstName'". Of course, this breaks if you have multiple FirstName rows for a given CustomerID, but if you are creating your tables properly both CustomerID and DBColumnName are part of your primary key......
Unescape HTML entities in Javascript?
...of a div reduces the XSS vulnerability, but it is still problematic in IE9 and Firefox.
function htmlDecode(input){
var e = document.createElement('textarea');
e.innerHTML = input;
// handle case of empty input
return e.childNodes.length === 0 ? "" : e.childNodes[0].nodeValue;
}
htmlDecode...
When should I use git pull --rebase?
I know of some people who use git pull --rebase by default and others who insist never to use it. I believe I understand the difference between merging and rebasing, but I'm trying to put this in the context of git pull . Is it just about not wanting to see lots of merge commit messages, or are...
How do I execute any command editing its file (argument) “in place” using bash?
I have a file temp.txt, that I want to sort with the sort command in bash.
14 Answers
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What is a regular expression for a MAC Address?
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The standard (IEEE 802) format for
printing MAC-48 addresses in
human-friendly form is six groups of
two hexadecimal digits, separated by
hyphens - or colons :.
So:
^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$
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How to run `rails generate scaffold` when the model already exists?
... you already have a model, you can still generate the necessary controller and migration files by using the rails generate option. If you run rails generate -h you can see all of the options available to you.
Rails:
controller
generator
helper
integration_test
mailer
migration
model
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grep a file, but show several surrounding lines?
... would like to grep for a string, but also show the preceding five lines and the following five lines as well as the matched line. How would I be able to do this?
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What does ':' (colon) do in JavaScript?
I'm learning JavaScript and while browsing through the jQuery library I see : (colon) being used a lot. What is this used for in JavaScript?
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Convert InputStream to byte array in Java
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You can use Apache Commons IO to handle this and similar tasks.
The IOUtils type has a static method to read an InputStream and return a byte[].
InputStream is;
byte[] bytes = IOUtils.toByteArray(is);
Internally this creates a ByteArrayOutputStream and co...