Tutorial by Examples: g

Any attempt to modify a const object results in undefined behavior. This applies to const variables, members of const objects, and class members declared const. (However, a mutable member of a const object is not const.) Such an attempt can be made through const_cast: const int x = 123; const_cas...

The change the definition of a db column, the query below can be used for example, if we have this db schema users ( firstname varchar(20), lastname varchar(20), age char(2) ) To change the type of age column from char to int, we use the query below: ALTER TABLE users CHANGE age...

When you install Git, you also get its visual tools, gitk and git-gui. gitk is a graphical history viewer. Think of it like a powerful GUI shell over git log and git grep. This is the tool to use when you’re trying to find something that happened in the past, or visualize your project’s history. ...

You will need a domain name from a registrar. In the gh-pages branch of your project repository, or the main branch of your username.github.io repository, create a CNAME file with the contents www.yourdomain.com - the canonical domain. At your registrar's domain configuration page, point your doma...

C# Maximizing the window driver.Manage().Window.Maximize(); This is fairly straightforward, ensures that our currently active window is maximized. Position of the window driver.Manage().Window.Position = new System.Drawing.Point(1, 1); Here we essentially move the currently active window t...

Like most of the other programming languages, T-SQL also supports IF..ELSE statements. For example in the example below 1 = 1 is the expression, which evaluates to True and the control enters the BEGIN..END block and the Print statement prints the string 'One is equal to One' IF ( 1 = 1) --<-...

In a single IF..ELSE statement, if the expression evaluates to True in the IF statement the control enters the first BEGIN..END block and only the code inside that block gets executed , Else block is simply ignored. On the other hand if the expression evaluates to False the ELSE BEGIN..END block ge...

You can apply formats within a procedure, e.g. to change the groupings within a proc summary or proc freq. Grouping SAS dates data example2 ; do Date = '01JUN2016'dt to '31AUG2016'dt ; Days = 1 ; output ; end ; run ; /* Summarise by year & month */ proc summary data=exampl...

Download the latest version of ANTLR and extract it to a folder. You can use also Maven, Gradle, or other build tool to depend on its runtime (the classes the generated grammars use): org.antlr:antlr4-runtime. In order to automatically -as part of the build process- generate the parser in a maven ...

A grouped VIEW is based on a query with a GROUP BY clause. Since each of the groups may have more than one row in the base from which it was built, these are necessarily read-only VIEWs. Such VIEWs usually have one or more aggregate functions and they are used for reporting purposes. They are also h...

$ sleep 500 & [1] 7582 Puts the sleep command in background. 7582 is the process id of the background process.

$ jobs [1] Running sleep 500 & (wd: ~) [2]- Running sleep 600 & (wd: ~) [3]+ Running ./Fritzing & First field shows the job ids. The + and - sign that follows the job id for two jobs denote the default job and next candidate def...

$ fg %2 sleep 600 %2 specifies job no. 2. If fg is used without any arguments if brings the last process put in background to the foreground. $ fg %?sle sleep 500 ?sle refers to the baground process command containing "sle". If multiple background commands contain the string, it w...

Press Ctrl + Z to stop a foreground process and put it in background $ sleep 600 ^Z [8]+ Stopped sleep 600

$ bg [8]+ sleep 600 &

Since a Vimscript file is a collection of Command mode actions, the user needs to specify that the desired actions should be executed in normal mode. Therefore executing a normal mode command like i, a, d etc. in Vimscript is done by prepending the command with normal: Going to the bottom of the f...

If you know you need a packet <packet>, but you don't know the exact name <packet-exact-name>, instead of searching with Google try with the following: sudo apt-get update apt-cache search <packet> This will return you a list of packets name with a description. Once you have i...

If you are running a command that returns hundreds of lines, but your interest is just on the lines that contains the word <word>, you should definitely use grep! For example try running: ifconfig -a Check the output, that could be only a few lines or quite long, if you have a server with ...

You can create and configure build types in the module-level build.gradle file inside the android {} block. android { ... defaultConfig {...} buildTypes { release { minifyEnabled true proguardFiles getDefaultProguar...

To create a blank image, use the imagecreatetruecolor function: $img = imagecreatetruecolor($width, $height); $img is now a resource variable for an image resource with $widthx$height pixels. Note that width counts from left to right, and height counts from top to bottom. Image resources can al...