Tutorial by Examples: n

Returns the value of any OS environment variable. MESSAGE OS-GETENV ("OS") VIEW-AS ALERT-BOX. On a Windows machine: MESSAGE OS-GETENV ("SHELL") VIEW-AS ALERT-BOX. Result on a Linux machine with Bash as current shell: ┌────── Message ───────┐ ...

Append one file to another. Status is checked in OS-ERROR OS-APPEND source target Appends targetfile.txt with sourcefile.txt: OS-APPEND VALUE("sourcefile.txt") VALUE("targetfile.txt").

Rename a file or directory. Status is in OS-ERROR. Can also be used to move files (or move and rename). OS-RENAME oldname newname Rename /tmp/old-name to /tmp/new-name: OS-RENAME VALUE("/tmp/old-name") VALUE("/tmp/new-name"). Move file c:\temp\old.txt to c:\new-dir\old....

Returns a list of all drives on a system. MESSAGE OS-DRIVES VIEW-AS ALERT-BOX. Result with four drives, C through F: On Linux the list will simply be empty as there by definitions are no "drives" connected. Listing directories is done in another way (INPUT FROM OS-DIR)

Client metrics cover the traffic between the client and the Varnish cache. sess_conn - Cumulative number of connections. client_req - Cumulative number of client requests. sess_dropped - Dropped connections because of a full queue. Monitor sess_conn and client_req to keep track of traffic vo...

Perhaps the most important performance metric is the hitrate. Varnish routes it's incoming requests like this: Hash, a cacheable request. This might be either hit or miss depending on the state of the cache. Hitpass, a not cacheable request. A hash with a miss and a hitpass will be fetched f...

You monitor the cached objects to see how often they expire and if they are "nuked". n_expired - Number of expired objects. n_lru_nuked - Last recently used nuked objects. Number of objects nuked (removed) from the cache because of lack of space. varnishstat -1 | grep "n_expire...

You need to keep track of some threads metrics to watch your Varnish Cache. Is it running out of OS resources or is it functioning well. threads - Number of threads in all pools. threads_created - Number of created threads. threads_failed - Number of times Varnish failed to create a thread. th...

There are a number of metrics describing the communication between Varnish and it's backends. The most important metrics here might be these: backend_busy - Number of http 5xx statuses recieved by a backend. With VCL you can configure Varnish to try another backend if this happens. backend_fail...

TypeScript allows editors to perform automated refactors which are aware of the rules of the languages. Here, for instance, Visual Studio Code is able to rename references to the inner foo without altering the outer foo. This would be difficult to do with a simple find/replace.

{-# LANGUAGE OverloadedStrings #-} module Main where import Data.Aeson main :: IO () main = do let example = Data.Aeson.object [ "key" .= (5 :: Integer), "somethingElse" .= (2 :: Integer) ] :: Value print . encode $ example

project('Posix-based Project', 'vala') add_project_arguments(['--nostdpkg'], language: 'vala') posix_dep = meson.get_compiler('vala').find_library('posix') executable('foo', 'foo.vala', dependencies: [posix_dep])

<?php $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, "https://api.dropboxapi.com/2/files/list_folder"); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); curl_setopt($ch, CURLOPT_CAINFO, "cacert.pem"); curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); curl_setopt($ch, CURLOP...

var foo = new uint8[12]; var bar = (owned) foo; assert (foo == null); The bar variable will own the value previously owned by foo.

public class Foo { public string prop { construct; get; } } Pure-Vala and lightweight class. This is useful if you need a compromise between efficiency of a struct and the feature of a full blown GObject class.

Say "Hello", Rails To get Rails saying "Hello", you need to create at minimum a controller and a view. A controller's purpose is to receive specific requests for the application. Routing decides which controller receives which requests. Often, there is more than one route t...

As edgeapi suggests, it provides an interface for protecting attributes from end-user assignment. This makes Action Controller parameters forbidden to be used in Active Model mass assignment until they have been whitelisted. In addition, parameters can be marked as required and flow through a prede...

import javax.inject.Singleton; import dagger.Module; import dagger.Provides; @Module public class VehicleModule { @Provides @Singleton Motor provideMotor(){ return new Motor(); } @Provides @Singleton Vehicle provideVehicle(){ return new Vehicle(...

Now that you have the providers for your different models, you need to request them. Just as Vehicle needs Motor, you have to add the @Inject annotation in the Vehicle constructor as follows: @Inject public Vehicle(Motor motor){ this.motor = motor; } You can use the @Inject annotation to ...

The connection between the provider of dependencies, @Module, and the classes requesting them through @Inject is made using @Component, which is an interface: import javax.inject.Singleton; import dagger.Component; @Singleton @Component(modules = {VehicleModule.class}) public interface Vehicl...