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MySQL - length() vs char_length()
...() returns the length of the string measured in characters.
This is especially relevant for Unicode, in which most characters are encoded in two bytes. Or UTF-8, where the number of bytes varies. For example:
select length(_utf8 '€'), char_length(_utf8 '€')
--> 3, 1
As you can see the E...
Get Unix Epoch Time in Swift
...alSince1970)
let preciseMilliseconds = Int(Date().timeIntervalSince1970 * 1_000)
let preciseMicroseconds = Int(Date().timeIntervalSince1970 * 1_000_000) // most likely precise
Unfortunately, however, in the year 2038, 32-bit numbers won't be usable for the Unix timestamp and they'll have to be 64-...
Getting output of system() calls in Ruby
If I call a command using Kernel#system in Ruby, how do I get its output?
15 Answers
...
How to emulate GPS location in the Android Emulator?
...latitude, longitude and if needed altitude on the device that is passed to all programs using the gps location provider. See the link above for further instructions.
The specific command to run in the console is
geo fix <longitude value> <latitude value>
I found this site useful for...
What's a good rate limiting algorithm?
...sages
per = 8.0; // unit: seconds
allowance = rate; // unit: messages
last_check = now(); // floating-point, e.g. usec accuracy. Unit: seconds
when (message_received):
current = now();
time_passed = current - last_check;
last_check = current;
allowance += time_passed * (rate / per);
if (...
Twitter Bootstrap Form File Element Upload Button
... Browse <input type="file" hidden>
</label>
This works in all modern browsers, including IE9+. If you need support for old IE as well, please use the legacy approach shown below.
This techniques relies on the HTML5 hidden attribute. Bootstrap 4 uses the following CSS to shim this f...
Why functional languages? [closed]
...onal languages. In some cases, this can make code more readable.
Traditionally, one of the big disadvantages of functional programming was also the lack of side effects. It's very difficult to write useful software without IO, but IO is hard to implement without side effects in functions. So most p...
Should I learn C before learning C++? [closed]
...es not mean you need to learn C first.
If you learn C++ you will eventually learn most of C with some differences between the languages that you will learn over time. In fact its a very hard thing to write proper C++ because intermediate C++ programmers tend to write C/C++.That is true whether ...
How to get the function name from within that function?
... ret = ret.substr(0, ret.indexOf('('));
return ret;
}
Using Function.caller is non-standard. Function.caller and arguments.callee are both forbidden in strict mode.
Edit: nus's regex based answer below achieves the same thing, but has better performance!
In ES6, you can just use myFunction.na...
How do I get user IP address in django?
...re you have reverse proxy (if any) configured correctly (e.g. mod_rpaf installed for Apache).
Note: the above uses the first item in X-Forwarded-For, but you might want to use the last item (e.g., in the case of Heroku: Get client's real IP address on Heroku)
And then just pass the request as argu...