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Check if PHP session has already started
I have a PHP file that is sometimes called from a page that has started a session and sometimes from a page that doesn't have session started. Therefore when I have session_start() on this script I sometimes get the error message for "session already started". For that I've put these lines:
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Equivalent C++ to Python generator pattern
...to signal termination
In your trivial example, it's easy enough. Conceptually:
struct State { unsigned i, j; };
State make();
void next(State&);
bool isDone(State const&);
Of course, we wrap this as a proper class:
class PairSequence:
// (implicit aliases)
public std::iterat...
How to find the Number of CPU Cores via .NET/C#?
...sical processors
Number of cores
Number of logical processors.
These can all be different; in the case of a machine with 2 dual-core hyper-threading-enabled processors, there are 2 physical processors, 4 cores, and 8 logical processors.
The number of logical processors is available through the En...
How do you Encrypt and Decrypt a PHP String?
... You may also use GCM (which removes the need for a separate MAC). Additionally, ChaCha20 and Salsa20 (provided by libsodium) are stream ciphers and do not need special modes.
Unless you chose GCM above, you should authenticate the ciphertext with HMAC-SHA-256 (or, for the stream ciphers, Poly1305 -...
How to write log base(2) in c/c++
...mpiler doesn't know that log10 will return the same value every time. For all the compiler knows, log10(2) could return different values on successive calls.
– abelenky
Jun 17 '10 at 21:24
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How do you find the current user in a Windows environment?
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The extra information with all the environment variables makes this a wonderful extended answer.
– bballdave025
May 21 at 19:32
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Compiling problems: cannot find crt1.o
... that's 64bit. You need the 32bit support files. For that, you need to install them
sudo apt install gcc-multilib
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Is there a way to detect if an image is blurry?
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Unless your image is cyclic, you will usually have sharp edges at the borders of the image that lead to very high frequencies
– Niki
Oct 14 '11 at 11:04
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Automatic vertical scroll bar in WPF TextBlock?
...g its vertical height. I expected a vertical scroll bar to appear automatically when that happens, but it didn't. I tried to look for a scroll bar property in the Properties pane, but could not find one.
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Pass an array of integers to ASP.NET Web API?
...iptor.GetConverter(elementType);
var values = Array.ConvertAll(s.Split(new[] { ","},StringSplitOptions.RemoveEmptyEntries),
x => { return converter.ConvertFromString(x != null ? x.Trim() : x); });
var typedValues = Array.CreateInstance(elementT...