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How do PHP sessions work? (not “how are they used?”)
...on files are usually stored in, say, /tmp/ on the server, and named sess_{session_id} . I have been looking at the contents and cannot figure out how they really work.
...
Can not connect to local PostgreSQL
...
This really looks like a file permissions error. Unix domain sockets are files and have user permissions just like any other. It looks as though the OSX user attempting to access the database does not have file permissions to acce...
Find nearest latitude/longitude with an SQL query
...
Additionally, it does not take into account the curvature of the earth. This would not be an issue for short search radii. Otherwise Evan's and Igor's answers are more complete.
– John Vance
N...
ActionController::InvalidAuthenticityToken
...h were page cached. Pages got buffered with a stale authenticity token and all actions using the methods post/put/delete where recognized as forgery attempts. Error (422 Unprocessable Entity) was returned to the user.
The solution for Rails 3:
Add:
skip_before_filter :verify_authenticity_token
...
Signed to unsigned conversion in C - is it always safe?
...herwise, if the type of the operand with signed integer type can represent all of the values of the type of the operand with unsigned integer type, then the operand with unsigned integer type is converted to the type of the operand with signed integer type.
Otherwise, both operands are converted t...
How do I declare a 2d array in C++ using new?
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A dynamic 2D array is basically an array of pointers to arrays. You can initialize it using a loop, like this:
int** a = new int*[rowCount];
for(int i = 0; i < rowCount; ++i)
a[i] = new int[colCount];
The above, for colCount= 5 and rowCount =...
What does the “@” symbol mean in reference to lists in Haskell?
...hout the @, you'd have to choose between (1) or (2):(3).
This syntax actually works for any constructor; if you have data Tree a = Tree a [Tree a], then t@(Tree _ kids) gives you access to both the tree and its children.
s...
Neo4j - Cypher vs Gremlin query language
...her the engine tries to find the best traversing solution itself.
I personally use Cypher because of its simplicity and, to date, I have not had any situations where I had to use Gremlin (except working with Gremlin graphML import/export functions). I expect, however, that even if i would need to u...
What is setup.py?
...ts and also from [I]Python prompts.
It does the similar job of pip, easy_install etc.,
Using setup.py
Let's start with some definitions:
Package - A folder/directory that contains __init__.py file.
Module - A valid python file with .py extension.
Distribution - How one package relates to ...
Static methods - How to call a method from another method?
...
class.method should work.
class SomeClass:
@classmethod
def some_class_method(cls):
pass
@staticmethod
def some_static_method():
pass
SomeClass.some_class_method()
SomeClass.some_static_method()
sha...