Tutorial by Examples: co

When you need to set a pixel value for something like Paint.setTextSize but still want it be scaled based on the device, you can convert dp and sp values. DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics(); float pixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12f, m...

COPY has two forms: COPY <src>... <dest> COPY ["<src>",... "<dest>"] (this form is required for paths containing whitespace) The COPY instruction copies new files or directories from <src> and adds them to the filesystem of the container at the ...

Make sure your image object is fully loaded before you try to draw it on the canvas with context.drawImage. Otherwise the image will silently fail to display. In JavaScript, images are not loaded immediately. Instead, images are loaded asynchronously and during the time they take to load JavaScript...

When a runtime error occurs, good code should handle it. The best error handling strategy is to write code that checks for error conditions and simply avoids executing code that results in a runtime error. One key element in reducing runtime errors, is writing small procedures that do one thing. Th...

This script, from here and here, will return all Tables and Columns where a specified value exists. This is powerful in finding out where a certain value is in a database. It can be taxing, so it is suggested that it be executed in a backup / test enviroment first. DECLARE @SearchStr nvarchar(100) ...

Directives can be used to build reusable components. Here is an example of a "user box" component: userBox.js angular.module('simpleDirective', []).directive('userBox', function() { return { scope: { username: '=username', reputation: '=reputation' }, ...

Once Powershell remoting is enabled (Enable-PSRemoting) You can run commands on the remote computer like this: Invoke-Command -ComputerName "RemoteComputerName" -ScriptBlock { Write host "Remote Computer Name: $ENV:ComputerName" } The above method creates a temporary se...

Connect to Redis server and allow admin (risky) commands ConfigurationOptions options = new ConfigurationOptions() { EndPoints = { { "localhost", 6379}}, AllowAdmin = true, ConnectTimeout = 60*1000, }; Connectio...

docker network connect app-backend myAwesomeApp-1 This command attaches the myAwesomeApp-1 container to the app-backend network. When you add a container to a user-defined network, the embedded DNS resolver (which is not a full-featured DNS server, and is not exportable) allows each container on ...

docker network disconnect app-backend myAwesomeApp-1 This command detaches the myAwesomeApp-1 container from the app-backend network. The container will no longer be able to communicate with other containers on the network it has been disconnected from, nor use the embedded DNS resolver to look u...

Data-only containers are obsolete and are now considered an anti-pattern! In the days of yore, before Docker's volume subcommand, and before it was possible to create named volumes, Docker deleted volumes when there were no more references to them in any containers. Data-only containers are obsolet...

Used by awk to split the input into multiple records. For example: echo "a b c|d e f" | awk 'BEGIN {RS="|"} {print $0}' produces: a b c d e f By default, the record separator is the newline character. Similarly: echo "a b c|d e f" | awk 'BEGIN {RS="|&quo...

In Common Lisp, if is the simplest conditional construct. It has the form (if test then [else]) and is evaluated to then if test is true and else otherwise. The else part can be omitted. (if (> 3 2) "Three is bigger!" "Two is bigger!") ;;=> "Three is bigger...

While attached to a running container with a pty assigned (docker run -it ...), you can press ControlP - ControlQ to detach.

Docker is just a fancy way to run a process, not a virtual machine. Therefore, debugging a process "in a container" is also possible "on the host" by simply examining the running container process as a user with the appropriate permissions to inspect those processes on the host (...

Mobile platforms like iOS automatically recognize phone numbers and turn them into tel: links. While the feature is very practical, the system sometimes detects ISBN codes and other numbers as telephone numbers. For mobile Safari and some other WebKit-based mobile browsers to turn off automatic pho...

docker-compose run service-name command If, for example, you wanted to run rake db:create in your web service, you'd use the following command: docker-compose run web rake db:create

Install Docker Engine. If you get a Permission denied error, Run sudo -i before the two commands below, then exit. Pull Docker Compose to /usr/local/bin/docker-compose. curl -L https://github.com/docker/compose/releases/download/1.7.1/docker-compose-`uname -s`-`uname -m` > /usr/loc...

LOOP has its own IF statement that can control how the clauses are executed: (loop repeat 1000 for x = (random 100) if (evenp x) collect x into evens else collect x into odds finally (return (values evens odds))) Combining multiple clauses in an IF ...

We can get a comma delimited string from multiple rows using coalesce as shown below. Since table variable is used, we need to execute whole query once. So to make easy to understand, I have added BEGIN and END block. BEGIN --Table variable declaration to store sample records DECLARE @...