Tutorial by Examples: ar

$ docker run -e "ENV_VAR=foo" ubuntu /bin/bash Both -e and --env can be used to define environment variables inside of a container. It is possible to supply many environment variables using a text file: $ docker run --env-file ./env.list ubuntu /bin/bash Example environment variable...

The array_intersect function will return an array of values that exist in all arrays that were passed to this function. $array_one = ['one', 'two', 'three']; $array_two = ['two', 'three', 'four']; $array_three = ['two', 'three']; $intersect = array_intersect($array_one, $array_two, $array_thre...

Using the Android API 23 or higher, very often such situation can be seen: This situation is caused by the structural change of the Android API regarding getting the resources. Now the function: public int getColor(@ColorRes int id, @Nullable Theme theme) throws NotFoundException should...

Suppose you have a Dockerfile ending with ENTRYPOINT [ "nethogs"] CMD ["wlan0"] if you build this image with a docker built -t inspector . launch the image built with such a Dockerfile with a command such as docker run -it --net=host --rm inspector ,nethogs will monitor the...

To execute operations in a container, use the docker exec command. Sometimes this is called "entering the container" as all commands are executed inside the container. docker exec -it container_id bash or docker exec -it container_id /bin/sh And now you have a shell in your running...

To temporarily mark a file as ignored (pass file as parameter to alias) - type: unwatch = update-index --assume-unchanged To start tracking file again - type: watch = update-index --no-assume-unchanged To list all files that has been temporarily ignored - type: unwatched = "!git ls-fil...

There are different cases where you must Explicitly specify the type parameters for a generic method. In both of the below cases, the compiler is not able to infer all of the type parameters from the specified method parameters. One case is when there are no parameters: public void SomeMethod<T...

Sometimes you need rewrite history with a rebase, but git push complains about doing so because you rewrote history. This can be solved with a git push --force, but consider git push --force-with-lease, indicating that you want the push to fail if the local remote-tracking branch differs from the b...

Sometimes, you need to work with an array while ensuring you don't modify the original. Instead of a clone method, arrays have a slice method that lets you perform a shallow copy of any part of an array. Keep in mind that this only clones the first level. This works well with primitive types, like n...

HTML <input type="range"></input> CSS EffectPseudo SelectorThumbinput[type=range]::-webkit-slider-thumb, input[type=range]::-moz-range-thumb, input[type=range]::-ms-thumbTrackinput[type=range]::-webkit-slider-runnable-track, input[type=range]::-moz-range-track, input[type=...

Given the text: foo: bar I would like to replace anything following "foo: " with "baz", but I want to keep "foo: ". This could be done with a capturing group like this: s/(foo: ).*/$1baz/ Which results in the text: foo: baz Example 1 or we could use \K,...

Header file UIColor+XYZPalette.h: @interface UIColor (XYZPalette) +(UIColor *)xyz_indigoColor; @end and implementation UIColor+XYZPalette.m: @implementation UIColor (XYZPalette) +(UIColor *)xyz_indigoColor { return [UIColor colorWithRed:75/255.0f green:0/255.0f blue:130/255.0f al...

Table Setup CREATE TABLE dbo.Employees ( EmployeeID INT NOT NULL PRIMARY KEY, FirstName NVARCHAR(50) NOT NULL, LastName NVARCHAR(50) NOT NULL, ManagerID INT NULL ) GO INSERT INTO Employees VALUES (101, 'Ken', 'Sánchez', NULL) INSERT INTO Employees VALUES (102, 'Keith', ...

Functions can modify the parameters passed to them if they are marked with the inout keyword. When passing an inout parameter to a function, the caller must add a & to the variable being passed. func updateFruit(fruit: inout Int) { fruit -= 1 } var apples = 30 // Prints "There's 3...

Switch statement make use of partial matching. let coordinates: (x: Int, y: Int, z: Int) = (3, 2, 5) switch (coordinates) { case (0, 0, 0): // 1 print("Origin") case (_, 0, 0): // 2 print("On the x-axis.") case (0, _, 0): // 3 print("On the y-axis.") ca...

You can make an UILabel with a dynamic height using auto layout. You need to set the numberOfLines to zero (0), and add a minimal height by setting up a constraints with a relation of type .GreaterThanOrEqual on the .Height attribute iOS 6 Swift label.numberOfLines = 0 let heightConstraint = ...

Array iteration comes in two flavors, foreach and the classic for-loop: a=(1 2 3 4) # foreach loop for y in "${a[@]}"; do # act on $y echo "$y" done # classic for-loop for ((idx=0; idx < ${#a[@]}; ++idx)); do # act on ${a[$idx]} echo "${a[$idx]}&...

The recommended way (Since ES5) is to use Array.prototype.find: let people = [ { name: "bob" }, { name: "john" } ]; let bob = people.find(person => person.name === "bob"); // Or, more verbose let bob = people.find(function(person) { return person.na...

To make express web application modular use router factories: Module: // greet.js const express = require('express'); module.exports = function(options = {}) { // Router factory const router = express.Router(); router.get('/greet', (req, res, next) => { res.end(options....

After receiving the arguments, you can print them as follows: int main(int argc, char **argv) { for (int i = 1; i < argc; i++) { printf("Argument %d: [%s]\n", i, argv[i]); } } Notes The argv parameter can be also defined as char *argv[]. argv[0] may co...