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MySQL: determine which database is selected?
After calling mysql_select_db to grab a database, is there any way to later output the name of the database that is currently selected? This seems very basic but I couldn't find anything on php.net or stackoverflow (all results are for "no database selected").
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Google access token expiration time
When I obtain an access_token from the Google API, it comes with an expires_in value. According to the documentation, this value indicates "The remaining lifetime of the access token".
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A Regex that will never be matched by anything
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This is actually quite simple, although it depends on the implementation / flags*:
$a
Will match a character a after the end of the string. Good luck.
WARNING:
This expression is expensive -- it will scan the entire line, find the en...
In what cases do I use malloc and/or new?
I see in C++ there are multiple ways to allocate and free data and I understand that when you call malloc you should call free and when you use the new operator you should pair with delete and it is a mistake to mix the two (e.g. Calling free() on something that was created with the new ...
Accessing members of items in a JSONArray with Java
...ades, following is the way to iterate org.json.JSONArray with java8 Stream API.
import org.json.JSONArray;
import org.json.JSONObject;
@Test
public void access_org_JsonArray() {
//Given: array
JSONArray jsonArray = new JSONArray(Arrays.asList(new JSONObject(
new HashMap...
Plot two histograms on single chart with matplotlib
...dom
import numpy
from matplotlib import pyplot
x = [random.gauss(3,1) for _ in range(400)]
y = [random.gauss(4,2) for _ in range(400)]
bins = numpy.linspace(-10, 10, 100)
pyplot.hist(x, bins, alpha=0.5, label='x')
pyplot.hist(y, bins, alpha=0.5, label='y')
pyplot.legend(loc='upper right')
pyplot....
Remove local git tags that are no longer on the remote repository
...cript to compare the tags generated by this list with the tags you have locally. Take a look at git show-ref --tags, which generates the tag names in the same form as git ls-remote).
As an aside, git show-ref has an option that does the opposite of what you'd like. The following command would l...
Get the value of an instance variable given its name
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The most idiomatic way to achieve this is:
some_object.instance_variable_get("@#{name}")
There is no need to use + or intern; Ruby will handle this just fine. However, if you find yourself reaching into another object and pulling out its ivar, there's a reasonably good ...
PHP session lost after redirect
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First, carry out these usual checks:
Make sure session_start(); is called before any sessions are being called. So a safe bet would be to put it at the beginning of your page, immediately after the opening <?php declaration before anything else. Also ensure there are no whitespaces/tabs be...
How to get orientation-dependent height and width of the screen?
I'm trying to programmatically determine the current height and width of my application. I use this:
11 Answers
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