Tutorial by Examples: t

Simply use the javascript: protocol to run the text as JavaScript instead of opening it as a normal link: <a href="javascript:myFunction();">Run Code</a> You can also achieve the same thing using the onclick attribute: <a href="#" onclick="myFunction(); r...

SELECT your_columns, COUNT(*) OVER() as Ttl_Rows FROM your_data_set idnameTtl_Rows1example52foo53bar54baz55quux5 Instead of using two queries to get a count then the line, you can use an aggregate as a window function and use the full result set as the window. This can be used as a base for fur...

Let's say I have this data: Table items idnametag1exampleunique_tag2foosimple42barsimple3bazhello51quuxworld I'd like to get all those lines and know if a tag is used by other lines SELECT id, name, tag, COUNT(*) OVER (PARTITION BY tag) > 1 AS flag FROM items The result will be: idnametag...

Given this data: dateamount2016-03-122002016-03-11-502016-03-141002016-03-151002016-03-10-250 SELECT date, amount, SUM(amount) OVER (ORDER BY date ASC) AS running FROM operations ORDER BY date ASC will give you dateamountrunning2016-03-10-250-2502016-03-11-50-3002016-03-12200-1002016-03-1410...

use feature qw( say ); # Numbers are true if they're not equal to 0. say 0 ? 'true' : 'false'; # false say 1 ? 'true' : 'false'; # true say 2 ? 'true' : 'false'; # true say -1 ? 'true' : 'false'; # true say 1-1 ? 'true' : 'false'; # fa...

Breakpoints pause your program once execution reaches a certain point. You can then step through the program line by line, observing its execution and inspecting the contents of your variables. There are three ways of creating breakpoints. From code, using the debugger; statement. From the brow...

QML comes with newer Version of the cross-platform application framework Qt. You can find the newest Version of Qt in the Downloads section. To create a new QML Project in the Qt Creator IDE, select "File -> New ..." and under "Applications" select "Qt Quick-Application...

3.0 Check if a string consists in exactly 8 digits: $ date=20150624 $ [[ $date =~ ^[0-9]{8}$ ]] && echo "yes" || echo "no" yes $ date=hello $ [[ $date =~ ^[0-9]{8}$ ]] && echo "yes" || echo "no" no

You can indent the text inside here documents with tabs, you need to use the <<- redirection operator instead of <<: $ cat <<- EOF This is some content indented with tabs `\t`. You cannot indent with spaces you __have__ to use tabs. Bash will remove empty space befo...

2.05b You can feed a command using here strings like this: $ awk '{print $2}' <<< "hello world - how are you?" world $ awk '{print $1}' <<< "hello how are you > she is fine" hello she You can also feed a while loop with a here string: $ while IFS...

To begin making modifications to the project's data, you have to obtain a local copy of the versioned project. Use the command line svn client or your favorite SVN client (TortoiseSVN, for example). Your local copy of the project is called a working copy in Subversion and you get it by issuing the c...

If you want to get the versioned project's data, but you don't need any of the version control capabilities offered by Subversion, you could run svn export <URL> command. Here is an example: $ svn export https://svn.example.com/svn/MyRepo/MyProject/trunk As a result, you will get the proje...

You are not the only person working on the project, right? This means that your colleagues are also making modifications to the project's data. To stay up to date and to fetch the modifications committed by others, you should run svn update command in your working copy. As a result, your working cop...

A a pointer to a piece of memory containing n elements may only be dereferenced if it is in the range memory and memory + (n - 1). Dereferencing a pointer outside of that range results in undefined behavior. As an example, consider the following code: int array[3]; int *beyond_array = array + 3; ...

To delete a remote branch in Git: git push [remote-name] --delete [branch-name] or git push [remote-name] :[branch-name]

If a remote branch has been deleted, your local repository has to be told to prune the reference to it. To prune deleted branches from a specific remote: git fetch [remote-name] --prune To prune deleted branches from all remotes: git fetch --all --prune

Listed from least expensive to most expensive at run-time: str::strtok is the cheapest standard provided tokenization method, it also allows the delimiter to be modified between tokens, but it incurs 3 difficulties with modern C++: std::strtok cannot be used on multiple strings at the same t...

Requirements: OS X 10.8 “Mountain Lion” or newer required to run Docker. While the docker binary can run natively on Mac OS X, to build and host containers you need to run a Linux virtual machine on the box. 1.12.0 Since version 1.12 you don't need to have a separate VM to be installed, as Docker...

Binaries Lua binaries are provided by most GNU/Linux distributions as a package. For example, on Debian, Ubuntu, and their derivatives it can be acquired by executing this: sudo apt-get install lua50 sudo apt-get install lua51 sudo apt-get install lua52 There are some semi-of...

To uninstall one or more locally installed packages, use: npm uninstall <package name> The uninstall command for npm has five aliases that can also be used: npm remove <package name> npm rm <package name> npm r <package name> npm unlink <package name> npm un ...