Tutorial by Examples: u

On a 8 cores Linux machine using GCC version 4.4, the C codes can be compiled and run the following way: $ gcc -std=c99 -O3 -fopenmp loop.c -o loopc -lm $ OMP_NUM_THREADS=1 ./loopc Computing 1000000 cosines and summing them with 1 threads took 0.095832s $ OMP_NUM_THREADS=2 ./loopc Computing 100...

realloc is conceptually equivalent to malloc + memcpy + free on the other pointer. If the size of the space requested is zero, the behavior of realloc is implementation-defined. This is similar for all memory allocation functions that receive a size parameter of value 0. Such functions may in fact ...

The following MATLAB script shows how to return multiple outputs in a single function: myFun.m: function [out1, out2, out3] = myFun(arg0, arg1) out1 = arg0 + arg1; out2 = arg0 * arg1; out3 = arg0 - arg1; end terminal: >> [res1, res2, res3] = myFun(...

Several 'insert' functions can "burn" ids. Here is an example, using InnoDB (other Engines may work differently): CREATE TABLE Burn ( id SMALLINT UNSIGNED AUTO_INCREMENT NOT NULL, name VARCHAR(99) NOT NULL, PRIMARY KEY(id), UNIQUE(name) ) ENGINE=InnoDB; IN...

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; }...

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...

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

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...

Detailed instructions on getting pthreads set up or installed.

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...

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...

Get information about the Authenticode signature from a signed script by using the Get-AuthenticodeSignature-cmdlet: Get-AuthenticodeSignature .\MyScript.ps1 | Format-List *

Dynamic SQL enables us to generate and run SQL statements at run time. Dynamic SQL is needed when our SQL statements contains identifier that may change at different compile times. Simple Example of dynamic SQL: CREATE PROC sp_dynamicSQL @table_name NVARCHAR(20), @col_name NVARCHAR(2...

Sometimes a new Java programmer will write code like this: public void check(boolean ok) { if (ok == true) { // Note 'ok == true' System.out.println("It is OK"); } } An experienced programmer would spot that as being clumsy and want to rewrite it as: publ...

Adding tags to "describe" or "it" blocks allows you to run only those examples with a given tag. Use the --tag (or -t) option to run examples that match a specified tag. The tag can be a simple name or a name:value pair. If a simple name is supplied, only examples with :name...