jeromer

# LICENSE: public domain

def calculate_initial_compass_bearing(pointA, pointB):
    """
    Calculates the bearing between two points.

    The formulae used is the following:
        θ = atan2(sin(Δlong).cos(lat2),
                  cos(lat1).sin(lat2) − sin(lat1).cos(lat2).cos(Δlong))

jeetsukumaran

#! /bin/bash

GCC_VERSION="5.2.0"
WORKDIR="$HOME/src/"
INSTALLDIR="/platform"

## NOTE: XCode must be installed (through App Store) and the following run to install command-line tools.
## THIS IS IMPORTANT! Among other things, it creates '/usr/include' and installs the system header files.
# xcode-select --install

soheilhy

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

lstude

This tutorial demonstrates how to add an "Indent Text" menu item to a Google spreadsheet so you can indent/outdent text.

• When the "Indent Text" menu item is selected, any cells within a single column selection will be indented by 5 spaces.

• You can increase or decrease the number of spaces the text is indented by changing the line below so that the "5" is changed to a larger or smaller number (depending on your preference):

newValues.push(['=CONCAT(REPT( CHAR( 160 ), 5),"' + values[i][0] + '")']);

brettcannon

graphitemaster

Working around offsetof limitations in C++:

There is sometimes a situation in which one needs to get the relative offset of a structure field, common examples of this include serialization frameworks which aid to serialize objects, vertex attributes for rendering (D3D, GL.), etc.

The most common technique for getting this information is through the offsetof macro defined in stddef.h. Unfortunately using the macro in C++ comes with a new set of restrictions that prevent some (subjectively valid) uses of it.

CMCDragonkai

Understanding the Memory Layout of Linux Executables

Required tools for playing around with memory:

• hexdump
• objdump
• readelf
• xxd
• gcore

jdforsythe

#!/bin/bash
git stash list
echo "Enter stash number to rename"
read stash_number

echo "Enter new name"
read new_name

stash_name="stash@{${stash_number}}"
echo "$stash_name"

shafik

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

baiwfg2

# References:
# https://cmake.org/cmake/help/latest/command/add_custom_target.html
# https://samthursfield.wordpress.com/2015/11/21/cmake-dependencies-between-targets-and-files-and-custom-commands/
# https://gist.github.com/socantre/7ee63133a0a3a08f3990
# https://stackoverflow.com/questions/24163778/how-to-add-custom-target-that-depends-on-make-install
# https://stackoverflow.com/questions/30719275/add-custom-command-is-not-generating-a-target
# https://stackoverflow.com/questions/26024235/how-to-call-a-cmake-function-from-add-custom-target-command
# https://blog.csdn.net/gubenpeiyuan/article/details/51096777

cmake_minimum_required(VERSION 3.10)