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C# Events and Thread Safety
... be out of date, but that's all. It won't cause a NullReferenceException.
And yes, there's certainly a race condition - but there always will be. Suppose we just change the code to:
TheEvent(this, EventArgs.Empty);
Now suppose that the invocation list for that delegate has 1000 entries. It's per...
Change key pair for ec2 instance
...e it in the same subnet, otherwise you will have to terminate the instance and create it again. - see here
Attach volume A to the new micro instance, as /dev/xvdf (or /dev/sdf)
SSH to the new micro instance and mount volume A to /mnt/tmp
$ sudo mount /dev/xvdf1 /mnt/tmp
Copy ~/.ssh/authorized_keys ...
Get selected value/text from Select on change
...
If you're googling this, and don't want the event listener to be an attribute, use:
document.getElementById('my-select').addEventListener('change', function() {
console.log('You selected: ', this.value);
});
<select id="my-select">
...
How to get the current time in Python
...
>>> print(datetime.datetime.now())
2009-01-06 15:08:24.789150
And just the time:
>>> datetime.datetime.now().time()
datetime.time(15, 8, 24, 78915)
>>> print(datetime.datetime.now().time())
15:08:24.789150
See the documentation for more information.
To save typing...
How to check command line parameter in “.bat” file?
... I need to have a ".bat" file where I need to check if user enters any command-line parameter or not. If does then if the parameter equals to -b then I will do something otherwise I will flag "Invalid input". If user does not enter any command-line parameter then I will do something. I have crea...
Why doesn't Java Map extend Collection?
...tion?
This was by design. We feel that
mappings are not collections and
collections are not mappings. Thus, it
makes little sense for Map to extend
the Collection interface (or vice
versa).
If a Map is a Collection, what are the
elements? The only reasonable answer
is "Key-va...
optional local variables in rails partial templates: how do I get out of the (defined? foo) mess?
I've been a bad kid and used the following syntax in my partial templates to set default values for local variables if a value wasn't explicitly defined in the :locals hash when rendering the partial --
...
Changing CSS Values with Javascript
...sy to set inline CSS values with javascript. If I want to change the width and I have html like this:
9 Answers
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How to retrieve a single file from a specific revision in Git?
I have a Git repository and I'd like to see how some files looked a few months ago. I found the revision at that date; it's 27cf8e84bb88e24ae4b4b3df2b77aab91a3735d8 . I need to see what one file looks like, and also save it as a ("new") file.
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What are sessions? How do they work?
...lication development, using python. I am coming across the terms 'cookies' and 'sessions'. I understand cookies in that they store some info in a key value pair on the browser. But I have a little confusion regarding sessions, in a session too we store data in a cookie on the user's browser.
...