Tutorial by Examples: t

Pre-commit

This hook is executed every time you run git commit, to verify what is about to be committed. You can use this hook to inspect the snapshot that is about to be committed. This type of hook is useful for running automated tests to make sure the incoming commit doesn't break existing functionality of...

Git • Hooks

Prepare-commit-msg

This hook is called after the pre-commit hook to populate the text editor with a commit message. This is typically used to alter the automatically generated commit messages for squashed or merged commits. One to three arguments are passed to this hook: The name of a temporary file that contains ...

Git • Hooks

Update

This hook is called after pre-receive, and it works the same way. It's called before anything is actually updated, but is called separately for each ref that was pushed rather than all of the refs at once. This hook accepts the following 3 arguments: name of the ref being updated, old object na...

Git • Hooks

Show changes between two branches

git diff branch1..branch2

Git • Git Diff

Cloning a file using streams

This program illustrates how one can copy a file using readable and writable streams using the createReadStream(), and createWriteStream() functions provided by the file system module. //Require the file System module var fs = require('fs'); /* Create readable stream to file in current direc...

Node.js • Filesystem I/O

Produce a patch-compatible diff

Sometimes you just need a diff to apply using patch. The regular git --diff does not work. Try this instead: git diff --no-prefix > some_file.patch Then somewhere else you can reverse it: patch -p0 < some_file.patch

Git • Git Diff

JSON API with ExpressJS

var express = require('express'); var cors = require('cors'); // Use cors module for enable Cross-origin resource sharing var app = express(); app.use(cors()); // for all routes var port = process.env.PORT || 8080; app.get('/', function(req, res) { var info = { 'string_value...

Node.js • Web Apps With Express

Handling Exception In Node.Js

Node.js has 3 basic ways to handle exceptions/errors: try-catch block error as the first argument to a callback emit an error event using eventEmitter try-catch is used to catch the exceptions thrown from the synchronous code execution. If the caller (or the caller's caller, ...) used try/ca...

Node.js • Exception handling

Completely uninstall Node.js on Mac OSX

In Terminal on your Mac operating system, enter the following 2 commands: lsbom -f -l -s -pf /var/db/receipts/org.nodejs.pkg.bom | while read f; do sudo rm /usr/local/${f}; done sudo rm -rf /usr/local/lib/node /usr/local/lib/node_modules /var/db/receipts/org.nodejs.*

Node.js • Uninstalling Node.js

Install nvm on Mac OSX

INSTALLATION PROCESS You can install Node Version Manager using git, curl or wget. You run these commands in Terminal on Mac OSX. curl example: curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.31.3/install.sh | bash wget example: wget -qO- https://raw.githubusercontent.com/creatio...

Node.js • nvm - Node Version Manager

Perfectly aligned buttons inside cards with flexbox

It's a regular pattern in design these days to vertically align call to actions inside its containing cards like this: This can be achieved using a special trick with flexbox HTML <div class="cards"> <div class="card"> <p>Lorem ipsum Magna proident ...

CSS • Flexible Box Layout (Flexbox)

Setting up a Theme

First we need to reference the Styles we want to use. <link rel="stylesheet" href="[file path]/kendo.common.min.css" /> <link rel="stylesheet" href="[file path]/kendo.[Theme].min.css" /> Now most of the controls use the [Theme], given in the a...

kendo-ui • Themes

Iterating through causes

It is often useful for debugging purposes to find the root cause of an error. In order to examine an error value that implements std::error::Error: use std::error::Error; let orig_error = call_returning_error(); // Use an Option<&Error>. This is the return type of Error.cause(). le...

Rust • Error handling

Log for a range of lines within a file

$ git log -L 1,20:index.html commit 6a57fde739de66293231f6204cbd8b2feca3a869 Author: John Doe <[email protected]> Date: Tue Mar 22 16:33:42 2016 -0500 commit message diff --git a/index.html b/index.html --- a/index.html +++ b/index.html @@ -1,17 +1,20 @@ <!DOCTYPE HTML> ...

Git • Browsing the history

The Pass Statement

pass is a null statement for when a statement is required by Python syntax (such as within the body of a for or while loop), but no action is required or desired by the programmer. This can be useful as a placeholder for code that is yet to be written. for x in range(10): pass #we don't want t...

Python Language • Loops

Changing the author of commits

You can use an environment filter to change the author of commits. Just modify and export $GIT_AUTHOR_NAME in the script to change who authored the commit. Create a file filter.sh with contents like so: if [ "$GIT_AUTHOR_NAME" = "Author to Change From" ] then export GIT_A...

Git • Rewriting history with filter-branch

Validate IP Addresses

Validates a value is a valid IP address var_dump(filter_var('185.158.24.24', FILTER_VALIDATE_IP)); var_dump(filter_var('2001:0db8:0a0b:12f0:0000:0000:0000:0001', FILTER_VALIDATE_IP)); var_dump(filter_var('192.168.0.1', FILTER_VALIDATE_IP)); var_dump(filter_var('127.0.0.1', FILTER_VALIDATE_IP)); ...

PHP • Filters & Filter Functions

Taking a screenshot and video (for kitkat only) from a device display

Screen shot: Option 1 (pure adb) The shell adb command allows us to execute commands using a device's built-in shell. The screencap shell command captures the content currently visible on a device and saves it into a given image file, e.g. /sdcard/screen.png: adb shell screencap /sdcard/screen.png...

Android • ADB (Android Debug Bridge)

Recording the display

4.4 Recording the display of devices running Android 4.4 (API level 19) and higher: adb shell screenrecord [options] <filename> adb shell screenrecord /sdcard/demo.mp4 (press Ctrl-C to stop recording) Download the file from the device: adb pull /sdcard/demo.mp4 Note: Stop the scre...

Android • adb shell

Absolute/Relative Imports

In Python 3, PEP 404 changes the way imports work from Python 2. Implicit relative imports are no longer allowed in packages and from ... import * imports are only allowed in module level code. To achieve Python 3 behavior in Python 2: the absolute imports feature can be enabled with from __futu...

Python Language • Incompatibilities moving from Python 2 to Python 3