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What is the best way to create constants in Objective-C

...s defined in foundation and compiles to compatible formats for C, C++, and Win32. As defined in NSObjCRuntime.h #if defined(__cplusplus) #define FOUNDATION_EXTERN extern "C" #else #define FOUNDATION_EXTERN extern #endif #if TARGET_OS_WIN32 #if defined(NSBUILDINGFOUNDATION) #define FO...
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How to encrypt/decrypt data in php?

...ollowing example would be recommended (>= 5.3): $key_size = 32; // 256 bits $encryption_key = openssl_random_pseudo_bytes($key_size, $strong); // $strong will be true if the key is crypto safe This can be done once or multiple times (if you wish to create a chain of encryption keys). Keep thes...
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What is the size of an enum in C?

I'm creating a set of enum values, but I need each enum value to be 64 bits wide. If I recall correctly, an enum is generally the same size as an int; but I thought I read somewhere that (at least in GCC) the compiler can make the enum any width they need to be to hold their values. So, is it possib...
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How to use unicode characters in Windows command line?

...this task). There are very few problems, as far as you understand the following facts/limitations: CMD and “console” are unrelated factors. CMD.exe is a just one of programs which are ready to “work inside” a console (“console applications”). AFAIK, CMD has perfect support for Unicode...
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How to save an HTML5 Canvas as an image on a server?

... # Decode the dataURL binary = atob(dataURL.split(',')[1]) # Create 8-bit unsigned array array = [] i = 0 while i < binary.length array.push binary.charCodeAt(i) i++ # Return our Blob object new Blob([ new Uint8Array(array) ], type: 'image/png') And canvas code here: can...
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“Failed to load platform plugin ”xcb“ ” while launching qt5 app on linux without qt installed

... Ubuntu 16.04 64bit. I got the problem for apparently no reasons. The night before I watched a movie on my VideoLan instance, that night I would like to watch another one with VideoLan. VLC just didn't want to run because of the error into t...
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Are there any standard exit status codes in Linux?

... 8 bits of the return code and 8 bits of the number of the killing signal are mixed into a single value on the return from wait(2) & co.. #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #incl...
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Error “gnu/stubs-32.h: No such file or directory” while compiling Nachos source code

... You're missing the 32 bit libc dev package: On Ubuntu it's called libc6-dev-i386 - do sudo apt-get install libc6-dev-i386. See below for extra instructions for Ubuntu 12.04. On Red Hat distros, the package name is glibc-devel.i686 (Thanks to Dav...
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Determine function name from within that function (without using traceback)

....25ms, 1.24ms, 0.5us, 0.16us normal (nonpythonic :) ) seconds accordingly (win7x64, python3.5.1) – Antony Hatchkins Jan 5 '17 at 20:55 ...
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How can I check if an ip is in a network in Python?

...s follows: import socket,struct def makeMask(n): "return a mask of n bits as a long integer" return (2L<<n-1) - 1 def dottedQuadToNum(ip): "convert decimal dotted quad string to long integer" return struct.unpack('L',socket.inet_aton(ip))[0] def networkMask(ip,bits): "C...