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Static constant string (class member)
...d::string's all the time too. The overhead is negligible, but you have far more options and are much less likely to write some fool things like "magic" == A::RECTANGLE only to compare their address...
– Matthieu M.
Oct 14 '09 at 14:24
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Checking network connection
...on, the DNS lookup itself may block the call to urllib_request.urlopen for more than a second. Thanks to @rzetterberg for pointing this out.
If the fixed IP address above is not working, you can find a current IP address for google.com (on unix) by running
% dig google.com +trace
...
google.co...
How to template If-Else structures in data-bound views?
...kout-switch-case) is quite flexible and can let you easily handle this and more complicated ones (more states than true/false).
Another option is to use dynamic templates. You would bind an area to one or more templates with the template name being used based on an observable. Here is a post that ...
Dealing with “java.lang.OutOfMemoryError: PermGen space” error
...his option brings down performance. It makes each request take three times more time than usual on our systems. Use with care.
– Eldelshell
Sep 3 '10 at 9:16
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Create a .csv file with values from a Python list
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Run cron job only if it isn't already running
... It's better.
Now you don't have to write the code yourself. Check out more reasons here: https://serverfault.com/a/82863
/usr/bin/flock -n /tmp/my.lockfile /usr/local/bin/my_script
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im...
Is Meyers' implementation of the Singleton pattern thread safe?
...scusses thread safe implementations of the pattern, and the conclusion is, more or less, that (in C++03) full locking around the instantiating method is basically the simplest way to ensure proper concurrency on all platforms, while most forms of double-checked locking pattern variants may suffer fr...
Mercurial: how to amend the last commit?
...1 undo the last (1) commit(s), so you can do it again (see this answer for more information).
Using the MQ extension, which is shipped with Mercurial
Even if it isn't shipped with Mercurial, the Histedit extension is worth mentioning
You can also have a look on the Editing History page of the Mer...
When to use static vs instantiated classes
...o decouple the dependencies out of your classes. This way the code is much more extensible and, the most important part for me, testable. Why is it more important to be testable? Because I don't always write library code, so extensibility is not that important, but testability is important when I do...
Dynamically Changing log4j log level
...level is simple; modifying other portions of the configuration will pose a more in depth approach.
LogManager.getRootLogger().setLevel(Level.DEBUG);
The changes are permanent through the life cyle of the Logger. On reinitialization the configuration will be read and used as setting the level at r...