Tutorial by Examples: i

to check if the given path exists path = '/home/john/temp' os.path.exists(path) #this returns false if path doesn't exist or if the path is a broken symbolic link

to check if the given path is a directory dirname = '/home/john/python' os.path.isdir(dirname) to check if the given path is a file filename = dirname + 'main.py' os.path.isfile(filename) to check if the given path is symbolic link symlink = dirname + 'some_sym_link' os.path.islink(symli...

A class or struct can have member functions as well as member variables. These functions have syntax mostly similar to standalone functions, and can be defined either inside or outside the class definition; if defined outside the class definition, the function's name is prefixed with the class' nam...

A common use of member functions is for encapsulation, using an accessor (commonly known as a getter) and a mutator (commonly known as a setter) instead of accessing fields directly. class Encapsulator { int encapsulated; public: int get_encapsulated() const { return encapsulated; }...

When a base class provides a set of overloaded functions, and a derived class adds another overload to the set, this hides all of the overloads provided by the base class. struct HiddenBase { void f(int) { std::cout << "int" << std::endl; } void f(bool) { std::cout &...

Member functions can also be declared virtual. In this case, if called on a pointer or reference to an instance, they will not be accessed directly; rather, they will look up the function in the virtual function table (a list of pointers-to-member-functions for virtual functions, more commonly know...

All non-static member functions have a hidden parameter, a pointer to an instance of the class, named this; this parameter is silently inserted at the beginning of the parameter list, and handled entirely by the compiler. When a member of the class is accessed inside a member function, it is silent...

configuration EnableIISFeature { node localhost { WindowsFeature IIS { Ensure = “Present” Name = “Web-Server” } } } If you run this configuration in Powershell (EnableIISFeature), it will produce a localho...

Starting a DSC on a remote machine is almost just as simple. Assuming you've already set up Powershell remoting (or enabled WSMAN). $remoteComputer = "myserver.somedomain.com" $cred = (Get-Credential) Start-DSCConfiguration -ServerName $remoteComputer -Credential $cred -Verbose Nb: A...

Sometimes it can be useful to test your Powershell data files and iterate through the nodes and servers. Powershell 5 (WMF5) added this neat little feature for doing this called Import-PowerShellDataFile . Example: $data = Import-PowerShellDataFile -path .\MydataFile.psd1 $data.AllNodes

To list available DSC resources on your authoring node: Get-DscResource This will list all resources for all installed modules (that are in your PSModulePath) on your authoring node. To list all available DSC resources that can be found in the online sources (PSGallery ++) on WMF 5 : Find-DS...

Before you can use a resource in a configuration, you must explicitly import it. Just having it installed on your computer, will not let you use the resource implicitly. Import a resource by using Import-DscResource . Example showing how to import the PSDesiredStateConfiguration resource and the F...

#!/usr/bin/env python """ An annotated simple socket client example in python. WARNING: This example doesn't show a very important aspect of TCP - TCP doesn't preserve message boundaries. Please refer to http://blog.stephencleary.com/2009/04/message-framing.html before adaptin...

Detailed instructions on getting pthreads set up or installed.

Passwords should never be stored as plain text! They should be hashed with a randomly generated salt (to defend against rainbow table attacks) using a slow password hashing algorithm. A high number of iterations (> 10k) can be used to slow down brute force attacks. A delay of ~100ms is acceptable...

Apart from primitives, the Explicit Layout structs (Unions) in C#, can also contain other Structs. As long as a field is a Value type and not a Reference, it can be contained in a Union: using System; using System.Runtime.InteropServices; // The struct needs to be annotated as "Explici...

Signing a script is done by using the Set-AuthenticodeSignature-cmdlet and a code-signing certificate. #Get the first available personal code-signing certificate for the logged on user $cert = @(Get-ChildItem -Path Cert:\CurrentUser\My -CodeSigningCert)[0] #Sign script using certificate Se...

To change the execution policy for the default scope (LocalMachine), use: Set-ExecutionPolicy AllSigned To change the policy for a specific scope, use: Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy AllSigned You can suppress the prompts by adding the -Force switch.

Often you might need to execute an unsigned script that doesn't comply with the current execution policy. An easy way to do this is by bypassing the execution policy for that single process. Example: powershell.exe -ExecutionPolicy Bypass -File C:\MyUnsignedScript.ps1 Or you can use the shorthan...

Getting the effective execution policy for the current session: PS> Get-ExecutionPolicy RemoteSigned List all effective execution policies for the current session: PS> Get-ExecutionPolicy -List Scope ExecutionPolicy ----- --------------- MachinePolicy Undefined...