Tutorial by Examples: p

The following command displays output only on the screen (stdout). $ ls The following command writes the output only to the file and not to the screen. $ ls > file The following command (with the help of tee command) writes the output both to the screen (stdout) and to the file. $ ls | ...

You can also use tee command to store the output of a command in a file and redirect the same output to another command. The following command will write current crontab entries to a file crontab-backup.txt and pass the crontab entries to sed command, which will do the substituion. After the substi...

You can pipe your output to multiple files (including your terminal) by using tee like this: $ ls | tee file1 file2 file3

By default tee command overwrites the file. You can instruct tee to append to the file using the –a option as shown below. $ ls | tee –a file

Here we will create a rest APi which will take file object as a multipart parameter from front end and upload it to S3 bucket using java rest API. Requirement :- secrete key and Access key for s3 bucket where you wanna upload your file. code:- DocumentController.java @RestController @Requ...

PostmarkMailSender.java public class PostmarkMailSender implements MailSender{ private static Logger logger = Logger.getLogger("com.postmark"); private String serverToken; private static Gson gson; static { GsonBuilder gsonBuilder = new GsonBuilder(); ...

class User(db.Model): id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(80)) email = db.Column(db.String(120), unique=True) posts = db.relationship('Post', backref='user') class Post(db.Model): id = db.Column(db.Integer,...

The curl source packages can be downloaded from the following page: https://curl.haxx.se/download.html However, the best way to install it is to use your package repository. For Linux distros, you can use apt-get, yum or rpm depending on the distribution you are using, so the exact command will b...

Child Processes are the way to go when one wants to run processes independently with different initialization and concerns. Like forks in clusters, a child_process runs in its thread, but unlike forks, it has a way to communicate with its parent. The communication goes both ways, so parent and chil...

A typical example of the implementation of a Looper thread given by the official documentation uses Looper.prepare() and Looper.loop() and associates a Handler with the loop between these calls. class LooperThread extends Thread { public Handler mHandler; public void run() { Lo...

A HandlerThread can be used to start a thread with a Looper. This looper then can be used to create a Handler for communications with it. HandlerThread thread = new HandlerThread("thread-name"); thread.start(); Handler handler = new Handler(thread.getLooper());

Detailed instructions on getting graphviz set up or installed.

In this example, we will plot a sine curve and a hyperbolic sine curve in the same plot with a common x-axis having different y-axis. This is accomplished by the use of twinx() command. # Plotting tutorials in Python # Adding Multiple plots by twin x axis # Good for plots having different y axis ...

In this example, a plot with curves having common y-axis but different x-axis is demonstrated using twiny() method. Also, some additional features such as the title, legend, labels, grids, axis ticks and colours are added to the plot. # Plotting tutorials in Python # Adding Multiple plots by twin ...

Promises handle errors differently to synchronous or callback-driven code. const p = new Promise(function (resolve, reject) { reject(new Error('Oops')); }); // anything that is `reject`ed inside a promise will be available through catch // while a promise is rejected, `.then` will not be ...

Numeric literals of more than a few digits are hard to read. Pronounce 7237498123. Compare 237498123 with 237499123 for equality. Decide whether 237499123 or 20249472 is larger. C++14 define Simple Quotation Mark ' as a digit separator, in numbers and user-defined literals. This can make it ...

Java StringWriter class is a character stream that collects output from string buffer, which can be used to construct a string. The StringWriter class extends the Writer class. In StringWriter class, system resources like network sockets and files are not used, therefore closing the StringWriter i...

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A simple HTTP Request for the resource /index.html. The host www.example.com is specified in the HTTP Host header. GET /index.html HTTP/1.1 Host: www.example.com

A possible response to the request above. The response contains the HTTP headers Date, Content-Type, Content-Encoding and Content-Length. HTTP/1.1 200 OK Date: Wed, 21 Jun 2017 10:58:03 GMT Content-Type: text/html; charset=UTF-8 Content-Encoding: UTF-8 Content-Length: 150 <response body&g...