Category: HTML

HTML Fun & Random Tutorial

HTML Fun & Random Tutorial

    I wash watching a show and it had a scene with a challenger board that had a honeycomb pattern in it with a gradient. I randomly thought to myself that I could do that with HTML and even animate it if I wished. So, for giggles, I decided to do just that and make a quick tutorial about it.

naruto_challenger_board
naruto_challenger_board

Thought Process

    Let’s first cover my thought process. I immediately thought that I could do this with a PNG that had a honeycomb pattern. It’s cells would be black with the lines being transparent. From there, I could use CSS’s linear-gradient to get the two colors in the image. Doing some googling got me a tillable honeycomb image but I did have to use Gimp to get the transparent parts and color exchange from white to black. Here is the end result of that: Honeycomb Image From there all I had to do was get two divs and set one of the with the image as the background and the other as a linear-gradient. OK, so we are set with the logic. Let’s look at the CSS.

CSS

    The CSS is pretty straightforward. We first make sure that the entire page is filled when we have our elements in it. So, we set padding and margins to zero for the html and body tags. We then define some base parameters for our two core div elements. I identafy them with IDs and they are overElm and underElm. We simply set their width and height settings to 100%. In addition, we set their positions fixed so that we can use z-index to place them in the proper top and bottom order.

    Now, the overElm has its background set to url(“honeycomb.png”); and repeat is set for both x and y ordinates. Then, underElm has its z-index set to -100 to make certain it is below overElm. That covers the CSS section. We will do one other CSS related thing but it will be referenced in our JavaScript section. Let’s cover our body tabs we need.

html, body {
    margin: 0em 0em 0em 0em;
    padding: 0em 0em 0em 0em;
}

#overElm, #underElm {
     width: 100%;
     height: 100%;
     position: fixed;
}

#overElm {
     background-image: url("honeycomb.png");
     background-repeat: repeat;
}

#underElm {
    z-index: -100;
}

Tags

    This part is super straightforward and so we an quickly go to the JavaScript section in a moment. Here is the breakdown. We have two div tags and they each have their respective IDs. See? Easypeasy. See below:

<div id="overElm"></div>
<div id="underElm"></div>

JavaScript

    OK, this is the most meaty part of the logic. We are going to use the setInterval JavaScript function and to create the animation. In addition, we will check to see if we want an animation at all. Before we do this we want to create a number of variables for use.

First, we get the element reference for underElm. Then, we create two color variables to be used in our linear-gradient setting. In addition, we create two color percent variables in order to drive how much gradient there actually is. Here we will use 50% for both so that they equally consume space and that there actually isn’t any gradation.

We also will create a degree variable and interval rate variable. Interval rate will dictate if we want to have a static color split or animated one. From there, we setup an if check and see if our interval rate is less than 0. If it is, it sets a static linar-gradient. Or if greater than, it will animate via the setInterval function. We pass our arguments to it for usage. And we are done! You can chnge the clors, its opacity, speed, and more to get a cool look for an HTML page or even video if you manage it right. Full code and video is below.

var elm = document.getElementById("underElm");
var color1        = "#09c759";
var color2        = "#c82f46";
var color1Percent = "50%";
var color2Percent = "50%";
var degInt        = 45;
var intervalRate  = -1;  // - number means do static than intervaled degree change
                         // 20 is nice and fast  500 is gradual and lower

if (intervalRate < 0) {
    elm.style.background = "linear-gradient(" + degInt + "deg,"
                           + color1 + " " + color1Percent +","
                           + color2 + " " + color2Percent + ")";
} else {
    var interval = setInterval(function () {
        elm.style.background = "linear-gradient(" + degInt + "deg,"
                               + color1 + " " + color1Percent +","
                               + color2 + " " + color2Percent + ")";

        degInt = (degInt <= 405) ? degInt += 5 : degInt = 45;

    }, intervalRate, elm, color1, color1Percent,
                          color2, color2Percent);
}

Full HTML & Code

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Honeycomb Gradient</title>

        <style media="screen">
            html, body {
                margin: 0em 0em 0em 0em;
                padding: 0em 0em 0em 0em;
            }

            #overElm, #underElm {
                width: 100%;
                height: 100%;
                position: fixed;
            }

            #overElm {
                background-image: url("honeycomb.png");
                background-repeat: repeat;
            }

            #underElm {
                z-index: -100;
            }
        </style>
    </head>
    <body>
        <div id="overElm"></div>
        <div id="underElm"></div>

         <script type="text/javascript">
             var elm           = document.getElementById("underElm");
             var color1        = "#09c759";
             var color2        = "#c82f46";
             var color1Percent = "50%";
             var color2Percent = "50%";
             var degInt        = 45;
             var intervalRate  = -1; // - number means do static than intervaled degree change
                                     // 20 is nice and fast  500 is gradual and lower

             if (intervalRate < 0) {
                 elm.style.background = "linear-gradient(" + degInt + "deg,"
                                        + color1 + " " + color1Percent +","
                                        + color2 + " " + color2Percent + ")";
             } else {
                 var interval = setInterval(function () {
                     elm.style.background = "linear-gradient(" + degInt + "deg,"
                                            + color1 + " " + color1Percent +","
                                            + color2 + " " + color2Percent + ")";

                     degInt = (degInt <= 405) ? degInt += 5 : degInt = 45;

                 }, intervalRate, elm, color1, color1Percent,
                                       color2, color2Percent);
             }

         </script>
    </body>
</html>

Video

Email-to-SMS Gateway List With Setup & Code Example

Email-to-SMS Gateway List With Setup & Code Example

email_to_sms
email_to_sms

    For personnel projects, one might need to send a message to a phone to give updates or alerts. This can be done relatively easily by using PHP and its “mail()” command. But, we need to know what gateway to send it to and what the number is. The number part is easy but gateways vary. So, here is a reference list of Email-to-SMS Gateways. In addition, there is a quick code reference part to help get the ball rolling. As a final point before starting, you will need a proper mailing system and FQDN to make sure messages get through. Some gateways are highly fickle and you might not always get the SMS sent through using this setup. So, don’t use this in a commercial context unless you do the aforementioned.

Code Reference:

    First, you’ll need the program “mail()” uses to send messages. In a terminal do:

sudo apt-get install sendmail

Then, edit the host file found at /etc/hosts. You’ll have something like this at the top: 127.0.0.1 localhost. You need it to be setup the proper FQDN syntax; so, something like this: 127.0.0.1 localhost.example.com is needed. After all that is setup (You might need to reboot.) you simply need to insert into a PHP script the following:

$number = "[email protected]";
$subject = "Your sybject message here.";         // Not used in text messages per say
$tmessage = wordwrap("Your message here.", 70 );

mail($number, $subject, $tmessage);

Gateway List:

Cell CarrierEmail Domain
AT&T Enterprise Pagingpage.att.net
AT&T Wirelesstxt.att.net
Alaska Communication Systemsmsg.acsalaska.com
Alltel text.wireless.alltel.com
Now part of AT&T
Australia T-Mobile/Optus Zoo (Optus)optusmobile.com.au
Appears they charge for the service
Bell Mobility & Solo Mobiletxt.bell.ca
Bluegrass Cellularsms.bluecell.com
Boost Mobilemyboostmobile.com
Cellcomcellcom.quiktxt.com
Cellular South (C Spire)cellularsouth1.com
(now cspire1.com)
Centennial Wirelesscwemail.com
Cincinnati Bellgocbw.com
Cingularcingular.com
Merged with AT&T Mobility 2007
Cingular Prepaidcingulartext.com
Cox WirelessDiscontinued 2012
Cricket Wirelessmms.cricketwireless.net
Digicel St. Luciadigitextlc.com
Fidofido.ca
Google VoiceNot an actual carrier
GCI Alask Digitel (GCI)mobile.gci.net
IV Cellular (Illinois Valley Cellular)ivctext.com
i wireless (iWireless)iwspcs.net (T-Mobile)
iwirelesshometext.com (Sprint PCS)
Koodo Mobilemsg.telus.com
Limetxt2lime.com
Metro PCSmymetropcs.com
MobilicityNo email-to-SMS service
MTS Mobilitytext.mtsmobility.com
NET10Determine NET10’s carrier
Nex-Techsms.nextechwireless.com
nTelospcs.ntelos.com
Will change to Sprint early 2016
O2 (M-mail)mmail.co.uk
O2 Powered Networks 
O2 UKo2imail.co.uk
Optusoptusmobile.com.au
Appears they charge for the service
Orangeorange.net
PC Telecommobiletxt.ca
PTel Mobiletmomail.net
Pioneer Cellularzsend.com
Pocket Wirelesssms.pocket.com
Republic Wirelesstext.republicwireless.com
Rogers Wirelesspcs.rogers.com
SaskTelsms.sasktel.com
Sprintmessaging.sprintpcs.com
Straight TalkDetermine Straight Talk’s carrier
Syringa Wirelessrinasms.com
T-Mobiletmomail.net
T-Mobile UKt-mobile.uk.net
Telstraonlinesms.telstra.com
Telus Mobilitymsg.telus.com
Threethree.co.uk
TracfoneDetermine Tracfone’s carrier
US Cellularemail.uscc.net
Unicelutext.com
Verizonvtext.com
Viaeroviaerosms.com
Virgin Mobilevmobl.com
Virgin Mobile Canadavmobile.ca
Virgin Mobile UKvxtras.com
VodafoneNo email-to-SMS service
Wind Mobiletxt.windmobile.ca

Check out my article regarding test servers so you can test this out properly!


Servers
Quick Test Server

Prevent SQL Injections

Prevent SQL Injections

sql injections
sql injections

    Preventing SQL injections is pretty easy once you know what you are doing. Some of you who are new to databases might think about character substitutions, character escaping, or just outright banning of certain characters; but, those options are laborious and not nearly as simple or elegant. Instead, we can use a technique called SQL Parameterization. It’s a fancy word for a straightforward process. For this guide, I’ll be referencing a database titled Movies.

    To explain it simply, what we are going to do is use a “?” in place of inserting our value. We then have our value tied to the “?” which will then be interpreted as a string literal. Since it is being handled as a string literal and is being kept from interpretation, this keeps us from having our databases deleted, stolen, or used in unforeseen ways.

The setup looks like this:

// Instead of this.
$updateComm = "SELECT title FROM Movies WHERE id = '" . $ID . "'";

// We have this.
$updateComm = "SELECT title FROM Movies WHERE id = ?";

Again, the question mark is like a reference marker/bind point. Our data gets tied to it and is never interpreted. We next do a prepare statement that’ll allow us to bind values. The first way we can do this is by binding the values to the field individually.

Let’s take a look:

// We first setup a command with the properly inserted question marks.
$updateComm = "UPDATE Movies SET title = ?, link = ?, date = ? WHERE id = ?";
 
// We then set it up for preparation.
$updateStatement = $db->prepare( $updateComm );

// We then insert to the bind points.
// Note: They are in order of appearance in the command. 
//       This is why we bind to title first and then links, etc.
//       Keep this in mind when setting up commands.
//       Also, we don't start at zero but one.
$updateStatement->bindValue( 1, "I, Robot", PDO::PARAM_STR );
$updateStatement->bindValue( 2, "LINK", PDO::PARAM_STR );
$updateStatement->bindValue( 3, "July 7, 2004", PDO::PARAM_STR );
$updateStatement->bindValue( 4, 666999, PDO::PARAM_INT );
 
// We then execute the command which is properly set up.
$updateStatement->execute();

The second option is to just pass the arguments as an array without individual binding. Note once more that it is all based on order of the question marks.

$updateComm = "UPDATE Movies SET title = ?, link = ?, date = ? WHERE id = ?";
 
// We then set it up for preparation.
$updateStatement = $db->prepare( $updateComm );

// Then, just pass parameters as an array to the execute method.
$updateStatement->execute( array( "I, Robot", "LINK", "July 7, 2004", 666999) );

In both cases, everything is properly sanitized for you and you don’t have to worry about rogue single quotes or DROP TABLE commands getting through. You’re done! Easy right? At this point, all you have to do is look up your language and how to do the above steps and implement them for secure database interactions. Look at Rosetta Code for how other languges setup parameterization. In addition, if you’ve read any of my other articles, pick a project like my PHP7, SQLite3, and Ajax Tutorial to practice this on in addition to learning other skills and techniques.

Java – JSP File Uploader Tutorial

Java – JSP File Uploader Tutorial

JSP Image
jsp image

    Java is one of my favorite programming languages due to its straightforward nature and plethora of built-in options. It has a robust tie with web related technologies such as HTML, CSS, and JavaScript and is made easy to leverage through its server Tomcat. In addition to all that, the community is strong and provides additional functionality through Java ARchives (JARs).

    Now, if you have a web application and want dynamic pages and to leverage Java, you can use Java Server Pages (JSP) to create dynamic interfaces and data streams/access. This tutorial will be on how to upload a file through an HTML Form and JSP processing it to save to the server. To do this, you’ll need to use Tomcat with or without Apache/Nginx and Java 8 or up. For this example, I’ll be using Tomcat in standalone than coupling it with one of the other options. I’m programing on an Ubuntu based distribution so be aware of how your system interacts with Java and vise versa.


To Top


To Bottom

Setup

Tomcat Download

    Let’s start off by getting Tomcat and setting it up. Go to Tomcat 9 Download page and look under Binary Distributions. There, click on either the 32bit or 64 bit “core” zip for Windows if on Windows or simply select the first “core” zip in the list if on Linux.
From there, unzip it to a location you want to work from. Mine is in my home directory under a folder called
“Portable_Apps”. I unzip it and called it “Tomcat-9”.

Tomcat Setup

    Once unzipped and located where you want it, you will want to change its setting in order to use it fully. So, head into the directory and you will see many folders. Of them, there are four key folders to really pay attention to for this task. They are “bin”, “conf”, “lib”, and “webapps”. First, head to “conf” and edit the tomcat-users.xml file. In general, you’ll want to add a user that can access the “manager-gui” application that allows you to control what web applications are present. To do this, head to the bottom of the file where the commented out accounts are. Copy or type out an account that isn’t commented out.

Mine looks looks so:

<user username="admin" password="1234" roles="tomcat,manager-gui"/> 

Please note that the password needs to be something that is actually strong and in addition to that you should try to name the user as something that can’t be guessed by others. Anyway, go ahead and save the file. From there, take a look at the server.xml file.

Find:

<Connector port="8080" protocol="HTTP/1.1"
                    connectionTimeout="20000"
                    redirectPort="8443"
                    address="0.0.0.0" />

You can change the port or add multiple Connector sections to have multiple ports accessible for multiple applications. Please note that I have added the “address” part and it is by default not present. The addition let’s my network connect to the application after I’ve allowed the port to be accessed through the firewall rules. In Linux, for me, this was as simple as making sure UFW was installed and up and then in a terminal doing “sudo ufw allow <portNumber>/tcp”.

    OK, before we start Tomcat, we will want to get some additional libraries so that we can handle a file being sent to the JSP file. Go to these links and find the newest versions.

Links: FileUpload and Commons IO

Once downloaded, simply unzip them and ignore all but the JAR that has the name and version number. Move these JARs to the “lib” folder that I mentioned earlier. If you started Tomcat before this step, stop it and then start it so the libraries will load. If not, we are then ready to start Tomcat. To do this, open a command line or terminal and change directories to the “bin” folder.

From there, do:

// Linux
./catalina.sh start

// Windows
.\catalina.bat start

You might need to make the shell file executable and you can do this by running “chmod +x catalina.sh” from the folder in the terminal. If everything went well, you should see “Tomcat started.” as part of the output. You can now go to your webbrowser and type localhost:8080. If you see “If you’re seeing this, you’ve successfully installed Tomcat. Congratulations!” then we are set. To stop the server, simply replace “start” with “stop”. It’s time we managed our applications a bit.

Tomcat Manage Applications

    On the page, to your right, you’ll see a button called “Manager App”. Click it and login using the user information you created earlier. Here, we’ll see all the applications that are present. This coincides with the “webapps” folder I mentioned. In manager, the paths math the folder names in the “webapps” folder. Only “ROOT” doesn’t follow the naming scheme since it is just a forward slash. “ROOT” also is the container for what you saw when you loaded the page. We’ll want to move its contents to another location. In the “webapps” folder add a new folder called “toor”. Then, in the manager page, find the “Deploy” section and type toor into the “Context Path” section. Click “Deploy” and the section will be added. The rest is up to you but I’d Undeploy the “docs” and “examples” section to clear up space. Note, the folders will be deleted if you do this.

    OK, move the “ROOT” contents to the “toor” folder and then create two folders in the “ROOT” folder. They are “data” and “WEB-INF”. In the “WEB-INF” folder add a file called “web.xml”.

In it, add:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
  version="4.0"
  metadata-complete="true">

  <display-name>File Uploader & Downloader</display-name>
  <description>
     File Uploader & Downloader
  </description>
</web-app>

OK, it’s time we write some code.

Code Breakdown

HTML

    There are really only two parts to this section, a form and an iframe. The rest is just fluff that HTML pages need for proper setup. Simply create the structure in an “index.html” file and insert the below into the “body” tag.

This is the important code:

<h2>File Uploader</h2>
    <form action="Uploader.jsp" method="post" enctype="multipart/form-data" target="FormSubmitter">
        <input type="reset" value="Clear">
        <input type="submit" name="submit"  value="Upload" />
        <input type="file" name="file" multiple />
    </form>
<iframe name="FormSubmitter" frameborder="0" style="width:100%;height:35em"></iframe>

Let’s break this down and understand the parts. We have a form and its action is the JSP file, “Uploader.jsp”. The JSP file will process the submitted info to it and save it. The method used is “post” because what is being submitted is a file or files. The encode type is “multipart/form-data” because we will have to submit files and this setting is what is used to do so. From there, to avoid redirecting the page on submission, we send the process to the iframe.

    In the form part, we have three input tags. The first simply clears the form data. The second submits the form or in this case the files. The third is the file selector. Reference the Full HTML section if you need to know the structure of the rest of the file. OK, we can now look at our JSP file, the good meaty Java code that glues this whole thing together.

JSP

    Go ahead and create a JSP file called “Uploader.jsp”. In the beginning, there was imports. In this beginning, we need a few of them.
Let’s look at them:

<%@ page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%>
<%@ page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%>
<%@ page import="org.apache.commons.fileupload.*"%>
<%@ page import="java.util.Iterator" %>
<%@ page import="java.util.List" %>
<%@ page import="java.io.File" %>

If we look at the imports, we already can get an idea of the structure of the program or take guesses as to how it might be written. We will iterate through a list of the uploaded file(s) and probably use the File object to write the selected file to a location. The other imports handle the actual receiving of the data. Now that we have the needed imports, let’s get some initial stuff set up.

Here is the start of the code:

<%
    boolean isMultipart = ServletFileUpload.isMultipartContent(request);
    String dirPath = getServletContext().getRealPath("/").replace('\\', '/') +
                                                                      "data/";
    String itemName;
    File file;


    out.println(
        "<!DOCTYPE html>"
        + "<html><head>"
        + "<meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" />"
        + "<title>Results</title>"
        + "</head> <body>"
    );

    Let’s break this down and understand the parts. The first is a boolean that we will check against to see if the data being sent is of multipart/form-data. The next part is the proper path to the “data” folder we created a while back. For Windows, I’m pretty sure you don’t need the “replace” part. We then setup a String called “itemName” that’ll be used to get the file name from the iterated data to then join with the “dirPath” so we can save it in the proper location. We also setup a File object we’ll use later. After all that, we print out the initial HTML syntax for return of the listed out “data” folder in HTML. We are well on our way to being able to upload files to our server. Let’s cover the middle meat of our JSP.

Here is the code:

    // Save file if present
    if (isMultipart) {
        FileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);
        List list = null;

        try { list = upload.parseRequest(request);
        } catch (FileUploadException e) { out.println(e); }

        Iterator itr = list.iterator();
        while (itr.hasNext()) {
            FileItem item = (FileItem) itr.next();
            if (!item.isFormField()) {
                try {
                    itemName = item.getName();
                    file = new File(dirPath + itemName);
                    item.write(file);
                } catch (Exception e) { }
            }
        }
    } else {
        out.println("<h2>Not multi-part transmitted...</h2>");
    }

As was stated, we first check to see if the data being sent is of multipart/form-data. If not we just return a message saying it’s incorrectly submitted. If it’s correct, we do some initial setting up processes by creating a FileItemFactory object. This is an interface for creating FileItem instances which are themselves a representation of the file or formfield data which will be stored in memory or on disk as temporary files. Files are stored in memory if small and on disk if too large when checked against the default size or the one you specify (We aren’t specifying size for this guide.). We then use a high level API for processing file uploads by way of the ServletFileUpload object.

    To determine files, we use the “parseRequest” method to get a list of files that are then sent to the previously created List object that is null. We do as previously mentioned and set up an Iterator object and traverse it with a while loop. In the while loop we create our FileItem which represents our listed file. We check to see if the FileItem instance represents a simple form field or an actual file. If it’s a file, we then get its name and then merge that name with the previously determined directory path. (Some of these settings can be setup in the “web.xml” we created but in this case we hard coded it.) This all is set in a new File object. We then use the FileItem object to write its data to the new File object we created and thus “upload” the file. Let’s finish the JSP code by returning a list of the files in the directory.

Here is the code:

    // List directory
    File curentDir = new File(dirPath);
    String[] list = curentDir.list();
    out.println("<ol>");
    for (int i=0; i<list.length; i++) {
            out.print("<li><a href='data/" + list[i] + "'/>" + list[i] + "</a></li>");
    }
    out.println("</ol>");
    out.println("</body></html>");
%>

    This last part is a bit of an added bonus. We will list the directory containing our files. Let’s break it down. We first create a new File Object and reference the “data” directory path. We list it out in a newly created String array object which we will use below. But next, we print out the “ordered list” tag. We then loop through the String array and printout HTML that has the “list item” tag and an anchor” tag nested in it that references the path and name of the file. We then close out all tags and party like it’s 1941.

Conclusion

Discussion

    At this point, you should add some CSS to get things styled the way you want it to. There isn’t too much I’m aware of that needs covering given the simplicity of the task. Upload file, process file, return data, and that’s it. You might want to look at other tasks like filling a database up with user input or make a directory traverser to view videos, images, or text files. It’s all up to you. If you know Java, then JSP is pretty much that but with web technologies.

For Next Time

    For next time, one should look at limiting upload sizes. In this example and for my personal usage, I don’t want a limitation since I’m working with my own files. In production though, it is IMPERATIVE that files be limited in size and there needs to be checks so as the server’s disk space isn’t by accident consumed entirely by a person uploading a file. Other than that, I have no other thoughts on the matter.

Full Code

HTML

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8" />
    <title>File Uploader</title>
</head>
<body>


<h2>File Uploader</h2>
    <form action="Uploader.jsp" method="post" enctype="multipart/form-data" target="FormSubmitter">
        <input type="reset" value="Clear">
        <input type="submit" name="submit"  value="Upload" />
        <input type="file" name="file" multiple />
    </form>

<iframe name="FormSubmitter" frameborder="0" style="width:100%;height:35em"></iframe>
</body>
</html>

JSP

<%@ page import="org.apache.commons.fileupload.servlet.ServletFileUpload"%>
<%@ page import="org.apache.commons.fileupload.disk.DiskFileItemFactory"%>
<%@ page import="org.apache.commons.fileupload.*"%>
<%@ page import="java.util.Iterator" %>
<%@ page import="java.util.List" %>
<%@ page import="java.io.File" %>

<%
    boolean isMultipart = ServletFileUpload.isMultipartContent(request);
    String dirPath = getServletContext().getRealPath("/").replace('\\', '/') +
                                                                      "data/";
    String itemName;
    File file;


    out.println(
        "<!DOCTYPE html>"
        + "<html><head>"
        + "<meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\" />"
        + "<title>Results</title>"
        + "</head> <body>"
    );

    // Save file if present
    if (isMultipart) {
        FileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);
        List list = null;

        try { list = upload.parseRequest(request);
        } catch (FileUploadException e) { out.println(e); }

        Iterator itr = list.iterator();
        while (itr.hasNext()) {
            FileItem item = (FileItem) itr.next();
            if (!item.isFormField()) {
                try {
                    itemName = item.getName();
                    file = new File(dirPath + itemName);
                    item.write(file);
                } catch (Exception e) { }
            }
        }
    } else {
        out.println("<h2>Not multi-part transmitted...</h2>");
    }

    // List directory
    File curentDir = new File(dirPath);
    String[] list = curentDir.list();
    for (int i=0; i<list.length; i++) {
        String name = list[i].toLowerCase();
        if (name.contains(".png") || name.contains(".jpg")||
            name.contains(".gif") || name.contains(".jpeg")) {
                out.print("<div>" +
                          "<img src='data/" + list[i] + "'/></div>");
        } else {
            out.print("<a href='data/" + list[i] + "'/><div>" + list[i] + "</div></a>");
        }
    }

    out.println("</body></html>");
%>

Images

before file select
before file select
file select
file select
file uploaded
file uploaded

file playing
file playing

If you liked this article, please check out the others I have written. One I recommend is my reference cheat sheet for HTML, CSS, and JavaScript. You can use it while styling your JSP file uploader application.


Web Technologies
Web Technologies

Simple PHP7, SQLite3, and AJAX Tutorial

Simple PHP7, SQLite3, and AJAX Tutorial

Ajax and PHP
Ajax and PHP

    Using PHP and AJAX can be somewhat confusing. But, the benefits are countless when it comes to doing web related projects. So, I wanted to do a simple tutorial/example of how to get things setup and how to do some basic insert and retrieval of data. For this project, I’m using PHP7, SQLite3, AJAX, Firefox, and Atom. You can use any browser with debugging options and any integrated development environment (IDE) or text editor you want. I choose SQLite3 as my database because it’s lightweight and good for applications that need a database.


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Setup

Creating The Layout & Files

Ultimately, my file and directory layout looks like this:

├── ajaxNphp  // This is my working dir
   ├── index.html
   ├── process.php
   └── resources
       └── server.db

The ajaxNphp folder is the root folder of this project. In this folder, we have a resources folder that holds the database and can hold CSS and JavaScript files among other stuff. ***Note: For this project, JavaScript and CSS are inline to the files! I’m trying to keep this as simple as possible.*** For this part, I recommend using the terminal since it can be faster and we will use it for some other stuff during this project. So, KEEP IT UP! Anyway, My project is located in my Downloads folder under the ajaxNphp folder.
So, I open a terminal and type:

cd ~/Downloads/ajaxNphp/

The tilda (~) means your home folder and the rest is pretty self explanatory. I then do:

mkdir resources && touch index.html process.php

This creates the resources directory where our database will go; if successful, it will then create our PHP and HTML files that we will use for the project. The next part is for us to actually install the tools so we can setup our database and start writing code.

The Tools

    I’m using an Ubuntu based operating system so I’ll show the commands you need to get PHP7, SQLite3, and Firefox installed.

sudo apt-get install sqlite3 php-sqlite3 php firefox

OK, now let’s just check that we have the proper versions installed.

PHP Check

// This will somewhat cleanup the version info on retrieval
php -v | awk '{ print $1 $2 }' | head -n1
// I get PHP7.0.25-0ubuntu0.16.04.1 which is PHP 7.0.25, so I'm set.

SQLite Check

sqlite -version
// I get 2.8.17

// If you do too, try:
sqlite3 -version
// If you get a return, then you are set for SQLite3.
// I get a return value so am set.

Ok, so now we need to determine an environment to work with. I recommend Atom because it has a robust set of plugins and themes that make it more pleasant to work with. You’ll need to get it through their website if you wish to use the same thing; but, any text editor will suit this project.

Setup The Database

    OK, so we now need to setup a database that we can query and insert to by using AJAX, PHP7, and SQLite3. I hope you’ve kept your terminal open as we will now change directory (cd) into the resources directory and launch SQLite3. So, here is what we do:

cd resources/ && sqlite3 server.db

We will then be presented with:

SQLite version <Your SQLite3 Version>
Enter ".help" for usage hints.
sqlite>

If you are seeing this, then let’s go ahead and create our database. I setup three columns for this project and they are title, date, and link. Recall, I’m doing a movies database so the first is for movie titles. The second is for when it was released, and the third is the cover image. So let’s create the table in our database.
Simply do:

CREATE TABLE Movies(title MAX, date varchar(10), link MAX);

If it was successful, you should see NO ERRORS and if you run :

.tables

you’ll get it returned. MAX means that the field can take the largest string possible. The varchar(10) means the field is limited to ten characters. There are other data types such as ints, but we will ignore them for now. Now, let’s insert some initial movie data by doing these below commands one at a time. Make sure there is an ending semi-colon for each!

// Date is in MM/DD/YYYY format

INSERT INTO Movies VALUES('Alien', '05/25/1979', 'https://images-na.ssl-images-amazon.com/images/I/61ujvw4OXNL._SX342_.jpg');

INSERT INTO Movies VALUES('Contact', '07/11/1997', 'http://www.filmsgraded.com/posters/01/1/8/8/84a.jpg');

INSERT INTO Movies VALUES('Paul', '03/18/2011', 'https://upload.wikimedia.org/wikipedia/en/thumb/9/96/Paul_poster.jpg/215px-Paul_poster.jpg');

// Check your work
SELECT * FROM Movies;
// You should see the data you entered returned.

// If so, then simply exit.
.exit

Excellent! The commands are pretty simple to understand. They even give a hint of what is going on. We use “INSERT INTO” to start the insert process. We reference our “Movies” table we created and then pass “VALUES” which match up with our title, date, link table layout. We end each command with a semi-colon. Next, we need a server to process PHP commands, interpret our form data, retrieve our data, etc.

Setup The Server

    There are many servers out there one can use and there are some servers that are for testing. If you want to see some options, read my post on Quick Test Servers. For this project, I’m using PHP’s built in server used for testing since it will process PHP and our HTML files.
If you’ve kept the terminal up do this:

cd .. && php -S 127.0.0.1:1212

It’s pretty straightforward for what we are doing here. We moved back to the top directory of the project using cd .. since we only moved down one directory, We then use the “php” command with “-S” as a switch to use its server. We give “-S” an argument of “localhost” (127.0.0.1) and a port of 1212. The port needs to be bigger than 1024 since any port lower and equal to that requires sudo to use. It then waits to process requests. We can use ctrl + c to kill the server which can be helpful for when we want to use ctrl + l to clear the terminal screen of any text output and restart. When your project is complete, you can omit the change directory command and just do the PHP et all part. Add an “&” to the command so that the process is persistent even if the terminal closes. Now, we are truly ready to code!

HTML

Our Basic HTML Template

    Let’s start off with a basic HTML template that we will add to shortly:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Test AJAX/PHP</title>

<script type="text/javascript">
</script>

</head>
<body>

<h2>Save Movie Info</h2>
<form action="process.php" method="post">
    <input type="text" title="Title" placeholder="Title" name="Title" value="">
    <input type="text" title="Date" placeholder="Date" name="Date" value="">
    <input type="text" title="Link" placeholder="Link" name="Link" value="">
    <input type="submit" name="saveInfo" value="Save">
    <button type="reset" value="Reset">Clear</button>
</forn>


<br/><br/>
<h2>Search Movie Info</h2>
<form>
    <input type="text" name="searchField"
           title="Search"
           placeholder="Search..."
           onkeyup="getData(this.value)"/>
</form>
<br/><br/>


<div id="dynDataField"></div>
</body>
</html>

    Let’s break this down. We have two forms with their own input fields. One form is used for saving new movie entries and the other searches the database and gets the data back. The form that saves new movie info has three fields and a submit button. The three fields correspond to the three columns in our database and Movies table. The submit action uses the forms submit action to send our process.php script POST data about the form for processing.

    The search form has one input field and an onkeyup event that calls a function called “getData”. This function has a parameter passed to it of “this.value” which will take the query that one has typed in. AJAX will be used in this instance to get data from the server as we type in a character. We have a div tag with an ID of “dynDataField” that we will reference to insert the returned data from the server. This is our bare bones HTML. But, it is pretty useless. Clicking any of the buttons or typing a search does nothing. So, let’s create an AJAX script to get our already entered data!

AJAX

AJAX Search Script

    At the heart of AJAX, there are 4 core steps for GET and 5 core steps for POST.

  1. Create an XMLHttpRequest object
  2. Setup an onreadystatechange function for the XMLHttpRequest object
  3. Open a connection with the XMLHttpRequest object
  4. With POST: Setup a setRequestHeader with an XMLHttpRequest object
  5. Send the data with an XMLHttpRequest object
    // Step 1: Create object
    var xhttp = new XMLHttpRequest();  // Create the xhttp object
    // Step 2: Setup an onreadystatechange function for the XMLHttpRequest object
    // This is actually run after send is done and the server spits out info.
    xhttp.onreadystatechange = function() {
        // Confirm we have a  successful connection. Then, receive the response info.
        // For PHP it is echo that sends it.
        // Loops seem to cause this to wait which means an array can be traversed
        // and the output could be written as a table, etc.
        if (this.readyState == 4 && this.status == 200) {
            // do something with the returned data
        }
    };
    // Step 3: Open connection
    // More or less, open a connection: @Params POST or GET, path to XML page or php script, set async t/f
    xhttp.open("GET", "process.php", true);
    // Step 4: Send the data and let server process it.
    //         After done processing it, onreadystatechange is triggered.
    xhttp.send();    // Start the process and send GET data


    //      For POST do and add these changes
    //  xhttp.open("POST", "process.php", true);
    // Used in POST to setup data types like JSON, XML, etc... MUST BE DONE AFTER OPEN
    // xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    // Example data structure for Sending POST with above RequestHeader. See that this mimics GET 
    // xhttp.send("fname=Henry&lname=Ford");
    // xhttp.sebnd(formData);  // Can use a string variable with formatted data structure instead

The above is the process. Here is what we setup in our scripts tag that’s in the head tag:

function getData(query) {
    if (query == "") {
        document.getElementById("dynDataField").innerHTML = "<p></p>";
        return;
    } else {
         var xhttp = new XMLHttpRequest();  // Create the xhttp object
         var formData = "dbQuery=" + query; // Our query being setup for processing
         // This is actually run after open and send are done
         xhttp.onreadystatechange = function() {
             if (this.readyState == 4 && this.status == 200) {
                 updatePage(this);  // Send the returned data to further process
             }
         };
         xhttp.open("POST", "process.php", true);  // Open the connection
         xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
         xhttp.send(formData);    // Start the process

    }
}

function updatePage(returnData) {
    // Get the echoed data and insert to div of dynDataField
    document.getElementById("dynDataField").innerHTML = returnData.responseText;
}

OK, so we have two functions here. One is for getting the data and the other inserts the results into our div. Get data checks to see if the input field is empty and if so leaves things as they are. If there is data in the field, it is then inserted into a variable “formData” and tied in with “dbQuery=”. This is what PHP will look at and use to insert into a database query. We then setup a statechange listener to wait for the server to finish processing the search and we send the result to the other function.

    After this setup part, we do the standard open process but use POST instead of GET. Then, we tell the server what kind of data this is. Recall, GET defines it for us but is limited and less secure while POST has more data formats and better security but we have to define it using the setrequestheader. We then send the data in its formatted string to the server for processing. This w3schools link has some more info about each part. In this instance, the PHP script transfers a string back to the requester. Note, we can transfer JSON, XML, and other data. But, a string or “responseText” is good for now.

Alright, all that’s left is to write our PHP script to process the search and our insert to table option.

PHP

Base PHP

    We have three core parts for the PHP project. We want to determine which form sent the POST. We then call one of two functions. One function will search the database. The other function will insert to the database.
Here is the basic setup:

<?php

// Retrieve data
function searchDB($QUERY) {
}

// Save new entry
function saveInfo($TITLE, $DATE, $INFOLINK) {
}

// Determin action
if(isset($_POST['saveInfo'])) {
    saveInfo($_POST["Title"], $_POST["Date"], $_POST["Link"]);
} elseif (isset($_POST['dbQuery'])) {
    searchDB($_POST['dbQuery']);
} else {
    echo "<h2 style='width:100%;background-color:#ff0000;color:#ffffff;text-align:center;'>Error! Illegal Access Method!</h2>";
}

?>

The part of interest here is the the determine action section. This is how we determine which function to call when a form is submitted or an AJAX call is made. If neither call the script, we drop an error and exit the script. We are simply checking if “saveInfo” or “dbQuery” are set. We then call the proper function and pass the data that is sent. Let’s now setup our search function.

Search Function

    As you might have seen, we are calling our search function “searchDB” and we are passing the “dbQuery” value to it.
So let’s see how we connect to the database and return data:

try {
    $serverPDO = new SQLite3('resources/server.db');
    $query = "SELECT * FROM Movies WHERE title LIKE '%" . $QUERY . "%' OR " .
                                         "date LIKE '%" . $QUERY . "%' OR " .
                                         "link LIKE '%" . $QUERY . "%'";
    $result = $serverPDO->query($query);

    while ($row = $result->fetchArray()) {
        echo "<div style='float: left;margin-left: 1em; margin-right: 1em;'>" .
             "<a href=" . $row["link"] ." target='blank'>" .
             "<img style='width:8em; height:10em;' src='" . $row["link"] . "'/></a><br/>" .
             "Title: " . $row["title"] .
             "<br/>Date: " . $row["date"] . "</div>";
    }

    if ($result->fetchArray() == 0) {
        echo "<div style='float:left;width:100%; background-color:pink;color:#ffffff;text-align:center;'>Nothing Found...</div>";
    } else {
        echo "<div style='float:left;margin-top:2em;width:100%; background-color:lightgreen;color:#ffffff;text-align:center;'>Search Completed...</div>";
    }
} catch (Exception $e) {
    echo "<h2 style='width:100%; background-color:ff0000;color:#ffffff;text-align:center;'>Error!</h2><br/>" . $e;
}

Let’s break this down. In our “searchDB” function, we have a try catch block that checks any exception that might occur. Technically, we really should be more specific to what exceptions might occur but for now, this will suffice. We try to create an SQLite3 database object and give it a local path name of “resources/server.db”. This is set to the “serverPDO” variable. We then create a “query” variable of type string that comprises of an SQL command that very broadly makes the database look at he table and see if any field matches the query. Please note, this is a very in-efficient way to do this as it looks at each field and then sees if any part is like the query both in upper, lower, and mixed casing. If we were being efficient, we’d base our queries on the columns and have either multiple input fields for the search with a “submit” button or use other techniques to keep the searches quick. Since this is a small database, performance isn’t poor and we can get away with this in a general context. Take note that the VALUES section is ordered just like we ordered it when we created the table columns.

    Anyway, we then execute the query and get the result set into the “result” variable. This is essentially a 2D array that comprises an array of result objects that then have an array of values for each object. This is why we use the while loop and access the “row” and then any values there in. We assign the values to a string formatted with HTML markup that is then echoed. After that, we echo whether we traversed an arrays by saying the search was or was not found.

    As I understand it, the “onreadystatechange” is triggered after the script is finished. So, all echos are collected by “onreadystatechange” and once the script sends an exit code the “onreadystatechange” sends what was echoed to whatever you setup to collect and parse the data.

Insert Function

    As you can tell, our insert function will take three paramets which are the title, date, and link.

if ($TITLE != "" && $DATE != "" && $INFOLINK != "") {
    try {
        $serverPDO = new SQLite3('resources/server.db');
        $command = "INSERT INTO Movies VALUES('" . $TITLE . "','" . $DATE . "','" . $INFOLINK . "')";
        $serverPDO->exec($command);

        echo "<h2 style='width:100%;background-color:#0000ff;color:#ffffff;text-align:center;'>Inserted to db...</h2><br/>" .
             "Title: " . $TITLE . "<br/>Date: " . $DATE . "<br/>Link: " . $INFOLINK;
    } catch (Exception $e) {
        echo "<h2 style='width:100%; background-color:ff0000;color:#ffffff;text-align:center;'>Error! Database Insert Failed...</h2><br/>" . $e;
    }
} else {
    echo "<h2 style='width:100%; background-color:ff0000;color:#ffffff;text-align:center;'>Error!</h2><br/>" .
         "<h3>A field is empty...</h3>" . $e;
}

Lets break this down. The first parts are pretty much the same as the search function with the exception of execute than query being the command. We also confirm that each field is filled and if not we generate an error HTML markup. We have a try catch block if they are filled. In the try section, we connect to the database. We create a “command” of type string that inserts the sent data from the form. We then echo a success or failure message. Take note that this insert process is not AJAX. Our page will redirect to the process.php file and the file will output HTML. I’m doing it this way to show you two ways of processing data and why AJAX is useful in that we aren’t being redirected. As you can see, it’s a much cleaner user experience to use AJAX and this PHP example shows why. You can change this to AJAX but I will leave that to you to figure out how.

Conclusion

Discussion

    We are DONE! Pat yourself on the back and get a cold beer or favorite beverage. You now have new possibilities available to you since you understand the basic concepts. Let’s do a quick recap and talk about pitfalls and the next steps one should take.

We start off by creating two files and one sub-folder. We then install our needed programs and a development environment. From there, we create our database in the sub-folder and the table in the database. It is important to recall that one of the fields is limited to a string size of 10. Anyway, we then entered some initial data so we could work with it after creating our code. After launching our PHP server, we create our initial HTML markup and talk about what we will do next. Next, we create our AJAX search script that checks against empties and so on. Since the HTML is done, we move on to the PHP. In the PHP, we check what’s sending the request and determine the necessary action from the POST data. We create our two functions and their logic which get called after the initial checks. Once the script exits, our AJAX sees this and we end the data to a function that then inserts the data to a div tag OR we get an HTML output in the case of the data insert form. We then drink our beverage and think about pitfalls and the next project we will do based off the work done here.

Pitfalls

    The first massive pitfall is that we aren’t sanitizing our data. NEVER do a production project without cleaning input data! I skipped it here because I’m lazy and this article would get longer than I want it to. It can be pretty easy to do though since there are libraries out there one can use. You should use a JavaScript library or your own scripts to check the input. I recommend checking through the server too but the JavaScript should get most issues.

    The next pitfall is that we aren’t checking the length of the date field. This can be done through JavaScript too and PHP can cover the process too. So, this would be one of the next steps to do as well as the above input sanitation.

    The next pitfall is that the search function implements a poor query structure. I mentioned this before but we are collating things to keep in mind so I mention it here too.

    I’m sure there are some other things of note but these three are the biggies. Let’s look at what our next steps might be with such a project.

Next Steps

    Here are some next steps to consider.

  • New Projects:
    • Use cookies to create a login system and account control to then access or create users for the database.
    • Use cookies and AJAX to create a tracking system that’ll insert data to the database about links clicked.
    • Create a meta search engine.
    • Create a password manager..
  • Improve Current Project:
    • Sanitize input fields to avoid exploits and future errors.
    • Implement a date field length check.
    • Make a better search system.

Result Images

ajax and php result
ajax and php result
ajax and php result 2
ajax and php result 2
error handling
error handling
error handling 2
error handling 2

db insert
db insert
HTML, CSS, JavaScript Useful Cheat Sheet!

HTML, CSS, JavaScript Useful Cheat Sheet!


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Web Technologies
Web Technologies

    I love web technologies because they provide a quick return on interest (ROI) and for the beginner gives immediate feedback in terms of accomplishment and sense of progress. There are many frameworks that one can use for a web based project but knowing the base elements these frameworks are comprised from is still important. Here is a reference list/cheat sheet of some of the most common HTML tags, CSS, and JavaScript one will likely use. This is great for Web Devs, Web Admins, coders, programmers, and the like.

HTML Tags

    Most HTML tags are setup as open and close tags. This means that most tags are a pare/set and denote where they start and end. The end tag has a forward slash (/) to indicate the tag is the end tag.

<tag>Stuff in tag...</tag>
(open tag)content(/end tag)

<!--Some tags end like this-->
<tag/>

<div>

    Div tags are considered devision tags and are used to section data on a page. CSS will then be used to style the tag by setting its position, setting the background color, setting the text color, etc. Think of the div as a container and your scaffolding for the page. Div tags are block elements.

<p>

    The P tag stands for paragraph tag and this is like a sub container for the div tag. It often holds text but can contain images, links, and other non-block tags. Browsers will automatically add some space (margin) before and after each <p> element. This behavior can be modified with CSS using the margin properties. P tags are block elements.

<span>

    The span tag is pretty much like the div tag. The difference between the two is that div is a block element which puts it on a separate line. A span tag, however, is an inline element, meaning that it can be on a line with other elements.


<img>

    The img tag stands for images. People like images and I like images.

<img src="https://www.itdominator.com/wp-content/uploads/2017/07/wp-cli.jpg" alt="If image doesn't render, this text will show instead." />

<a>

    Anchor tags link to parts on the same page or to new pages entirely. They are essentially links.

<!--To an external page...-->
<a href="http://www.google.com" target="_blank">Google</a>

<!--This will jump to the content that is wrapped with another anchor tag on the same page.-->
<a href="#colors">Colors</a>

<a name="colors">
<p>Colors are cool. The primary colors are red, green, and blue.</p>
</a>

<table>

    Table is a block element that denotes there will be sub elements of th, tr, td. There are others but these are the core parts. Th stands for table header and
is inset within a tr (table row). Tr is table row which makes a row for the table. Td is table data which is like a column and is inset in a table row too.

border-collapse: separate (default):

FirstnameLastname
TomGar
LoisGriffin

border-collapse: collapse:

FirstnameLastname
PeterGriffin
LoisMatt

form

    A form is used to submit data to the server. There are many form objects one can use. Below is a table covering all HTML5 form objects and their code and examples.

ObjectPreview HTML 5 code
Label

<label>Texte</label>
Button

<input type=”button” name=”name” value=”Bouton”>
Image button


<input type=”image” src=”image/bimage.jpg”>
Text field

<input type=”text” name=”text” value=”empty”>
Password

<input type=”password” name=”monpass” value=”12345″>
Date

<input type=”date” name=”date” value=”<?php echo $today?>”>
Date and time

<input type=”datetime” name=”time” value=”<?php echo $now?>”>
Time<time>2013-06-27</time>
Number

<input type=”number” name=”num” value=”12345″>
Color

<input type=”color” name=”color” value=””>
Search input

<input type=”search” name=”” list=”datalist” value=””>
Data
Dix
<data value=”10″>Ten</data>
Check box

<input type=”checkbox” name=”checkbox1″ value=”checkbox”>
Radio group



<label>Choice 1
<input type=”radio” name=”radio1″ value=”radio1″>
</label>
<label>Choice 2
<input type=”radio” name=”radio1″ value=”radio2″>
</label>
Textarea

<textarea name=”textarea”>content</textarea>
Range


<input type=”range” min=”-100″ max=”100″
value=”0″ step=”2″ name=”power” list=”powers”>
<datalist id=”powers”>
<option value=”0″>
<option value=”-30″>
<option value=”30″>
<option value=”+50″>
</datalist>
Data listTo be used with input
<datalist id=”identifier”>
<option value=”1″>
<option value=”2″>
<option value=”3″>
</datalist>
Select

<select name=”select”>
<option>Alpha</option>
<option>Beta</option>
<option>Delta</option>
</select>
Select list

<select name=”select2″ size=”3″>
<option>Alpha</option>
<option>Beta</option>
<option>Delta</option>
</select>
Menu

  • New
  • Open
  • Save
  • <menu type=”context”>
    <li>New</li>
    <li>Open</li>
    <li>Save</li>
    </menu>
    Toolbar

  • <menu type=”toolbar”>
    <li><button type=”button” onclick=”fnew()”>New</button></li>
    <li><button type=”button” onclick=”fopen()”>Open</button></li>
    <li><button type=”button” onclick=”fsave()”>Save</button></li>
    </menu>
    Combo box


    <input type=”text” list=”comboid”>
    <datalist id=”comboid”>
    <option value=”0″>
    <option value=”-30″>
    <option value=”30″>
    <option value=”+50″>
    </datalist>
    File upload

    <input type=”file” name=”file”>
    Image & caption

    Caption

    <figure>
    <img src=”image/image.gif”>
    <figcaption>Caption</figcaption>
    </figure>
    Fieldset
    Title

    …Content…

    <fieldset>
    <legend>Title </legend>

    <p>Content</p>
    </fieldset>
    Output

    <output onforminput=”value = 2 + 2″></output>
    Meter
    12 units
    <meter min=0 max=24 value=12>12 units</meter>
    Progress 0%
    <progress id=”prog” max=100>
    Summary

    Overview
    term
    definition

    <details>
    <summary>
    Presentation
    </summary>
    <dl>
    <dt>term</dt>
    <dd>definition</dd>


    </dl>
    </details>
    Submit button

    <input type=”submit” name=”submit” value=”Submit”>
    Clear/Reset button

    <input type=”reset” name=”clear” value=”Clear”>

    HTML Entities

        HTML entities are used in place of reserved characters in HTML. Characters that are not present on your keyboard can also be replaced by entities as well. The most common are listed in a table below.

    ResultDescriptionEntity NameEntity Number
    non-breaking space&nbsp;&#160;
    <less than&lt;&#60;
    >greater than&gt;&#62;
    &ampersand&amp;&#38;
    double quotation mark&quot;&#34;
    single quotation mark (apostrophe)&apos;&#39;
    ¢cent&cent;&#162;
    £pound&pound;&#163;
    ¥yen&yen;&#165;
    euro&euro;&#8364;
    ©copyright&copy;&#169;
    ®registered trademark&reg;&#174;

    HTML Notes

    Recommended Default HTML Markup Before Content Is Added

    <!DOCTYPE html> <!--Tells a browser its an html page-->
    <html lang="en">
    <head>
      <meta charset="utf-8">  <!--Encoding model-->
      <title>Title seen on its tab</title>
      <link rel="stylesheet" href="/css/master.css"> <!-- Attach CSS through a path -->%MINIFYHTML218dcf06c901c72f77f8c7d70df129535%</head>
    <body>
    
    <!-- content goes here... -->
    
    
    <script src="resources/scripts/script.js" charset="utf-8"></script>  <!-- Attach Javascript File through path -->
    </body>
    </html>
    

    Block Elements

        In general, HTML elements can be divided into two categories : block level and inline elements. HTML block level elements can appear in the body of an HTML page. It can contain another block level as well as inline elements. By default, block-level elements begin on new lines. Block level elements create larger structures (than inline elements).

    • p
    • h1, h2, h3, h4, h5, h6
    • ol, ul
    • pre
    • address
    • blockquote
    • dl
    • div
    • fieldset
    • form
    • hr
    • noscript
    • table

    Inline Elements

        HTML inline elements can appear in the body of an HTML page. They can contain data and other inline elements. By default, inline elements do not begin on new lines. Inline elements create shorter structures (than block elements).

    • b, big, i, small, tt
    • abbr, acronym, cite, code, dfn, em, kbd, strong, samp, var
    • a, bdo, br, img, map, object, q, script, span, sub, sup
    • button, input, label, select, textarea

    Margins

        Margins are the spacing around an element.

    This span tag has 2em margin set…

    Padding

        Padding is the spacing internal to an element and its “walls”.

    This span tag has 2em padding set…

    CSS

    Examples/Logic

    SelectorExampleExample description
    .class.introSelects all elements with class=”intro”
    #id#firstnameSelects the element with id=”firstname”
    **Selects all elements
    elementpSelects all <p> elements
    element,elementdiv, pSelects all <div> elements and all <p> elements
    element elementdiv pSelects all <p> elements inside <div> elements
    element>elementdiv > pSelects all <p> elements where the parent is a <div> element
    element+elementdiv + pSelects all <p> elements that are placed immediately after <div> elements
    element1~element2p ~ ulSelects every <ul> element that are preceded by a <p> element
    [attribute][target]Selects all elements with a target attribute
    [attribute=value][target=_blank]Selects all elements with target=”_blank”
    [attribute~=value][title~=flower]Selects all elements with a title attribute containing the word “flower”
    [attribute|=value][lang|=en]Selects all elements with a lang attribute value starting with “en”
    [attribute^=value]a[href^=”https”]Selects every <a> element whose href attribute value begins with “https”
    [attribute$=value]a[href$=”.pdf”]Selects every <a> element whose href attribute value ends with “.pdf”
    [attribute*=value]a[href*=”w3schools”]Selects every <a> element whose href attribute value contains the substring “w3schools”
    :activea:activeSelects the active link
    ::afterp::afterInsert something after the content of each <p> element
    ::beforep::beforeInsert something before the content of each <p> element
    :checkedinput:checkedSelects every checked <input> element
    :disabledinput:disabledSelects every disabled <input> element
    :emptyp:emptySelects every <p> element that has no children (including text nodes)
    :enabledinput:enabledSelects every enabled <input> element
    :first-childp:first-childSelects every <p> element that is the first child of its parent
    ::first-letterp::first-letterSelects the first letter of every <p> element
    ::first-linep::first-lineSelects the first line of every <p> element
    ype.asp”>:first-of-typep:first-of-typeSelects every <p> element that is the first <p> element of its parent
    :focusinput:focusSelects the input element which has focus
    :hovera:hoverSelects links on mouse over
    sp”>:in-rangeinput:in-rangeSelects input elements with a value within a specified range
    :invalidinput:invalidSelects all input elements with an invalid value
    :lang(language)p:lang(it)Selects every <p> element with a lang attribute equal to “it” (Italian)
    sp”>:last-childp:last-childSelects every <p> element that is the last child of its parent
    ype.asp”>:last-of-typep:last-of-typeSelects every <p> element that is the last <p> element of its parent
    :linka:linkSelects all unvisited links
    :not(selector):not(p)Selects every element that is not a <p> element
    sp”>:nth-child(n)p:nth-child(2)Selects every <p> element that is the second child of its parent
    hild.asp”>:nth-last-child(n)p:nth-last-child(2)Selects every <p> element that is the second child of its parent, counting from the last child
    f-type.asp”>:nth-last-of-type(n)p:nth-last-of-type(2)Selects every <p> element that is the second <p> element of its parent, counting from the last child
    ype.asp”>:nth-of-type(n)p:nth-of-type(2)Selects every <p> element that is the second <p> element of its parent
    ype.asp”>:only-of-typep:only-of-typeSelects every <p> element that is the only <p> element of its parent
    sp”>:only-childp:only-childSelects every <p> element that is the only child of its parent
    :optionalinput:optionalSelects input elements with no “required” attribute
    ange.asp”>:out-of-rangeinput:out-of-rangeSelects input elements with a value outside a specified range
    sp”>:read-onlyinput:read-onlySelects input elements with the “readonly” attribute specified
    sp”>:read-writeinput:read-writeSelects input elements with the “readonly” attribute NOT specified
    :requiredinput:requiredSelects input elements with the “required” attribute specified
    :root:rootSelects the document’s root element
    ::selection::selectionSelects the portion of an element that is selected by a user
    :target#news:targetSelects the current active #news element (clicked on a URL containing that anchor name)
    :validinput:validSelects all input elements with a valid value
    :visiteda:visitedSelects all visited links

    IDs

        ID selectors are supposed to be unique within the HTML document. When queried with JavaScript it should return a single element but it can return an array/list if the web developer set the document with multiple IDs of the same type. Standards dictate this is poor form if done.

    <!-- The IDs are arbitrary. -->
    
    <div id="left-container"> <!-- Content --> </>
    <div id="middle-container"> <!-- Content --> </>
    <div id="right-container"> <!-- Content --> </>
    

    Classes

        Class selectors don’t have to be unique within the HTML document. When queried with JavaScript it usually returns an array/list.

    <!-- The Class is arbitrary. -->
    
    <div class="book"> <!-- Content --> </>
    <div class="book"> <!-- Content --> </>
    <div class="book"> <!-- Content --> </>
    

    CSS Button Generator Button Generator

        Quickly make buttons…

    Button













    JavaScript

    Get Elements By ID/Class/TagName/CSS Selector

        Getting elements by id, class, and tag among other options is a sizeable chunk of the JavaScripting one will do. This allows us to interact with the DOM

    // Get HTML element(s) with specified id.
      var x = document.getElementById('id');
    
    // Get HTML elements with specified class.
      var x = document.getElementsByClassName('className');
    
    // Get HTML elements with specified tag.
      var x = document.getElementsByTagName('tagName');
    
    // Get HTML elements tht matches a specified CSS selector
    // This example returns a list of all  elements with class="icon".
      var x = document.querySelectorAll("img.icon"); 
    

    Function

        The basic block of coding we all know and have come to love. Yes…the function.

    function sum(a, b) {
        return a + b;      // The function returns the sum of a and b
    }
    var sumVal = sum(2,4);
    alert(sumVal);  // Will pop-up saying 6
    

    If Statement

        Check the conditions.

    if (condition) {
    }
    

    Loops

        Loops baby, they’re needed and these will meet your needs.

    // Standard loop
    for (var i=0; i<array.length; i++) {
       array[i].innerHTML;
    }
    
    // For In Loop
    for (var tag in elements) {
        // Do stuff while there are tags to work on
    }
    
    // While Loop
    while (condition) {
        // Do stuff while condition is met
    }
    
    // Do While
     do {
        // One at least one and keep doing stuff while condition is met
    }
    while (condition);
    

    Switch/Case Statement

        Good for menu stuff, switch/case statements are ready for the job.

    var day;
    switch (new Date().getDay()) {
        case 0:
            day = "Sunday";
            break;
        case 1:
            day = "Monday";
            break;
        case 2:
            day = "Tuesday";
            break;
        case 3:
            day = "Wednesday";
            break;
        case 4:
            day = "Thursday";
            break;
        case 5:
            day = "Friday";
            break;
        case  6:
            day = "Saturday";
    }
    alert(day);
    

    Alert & Console Log

        Error logging is helpful. The two way to do this are through alerts and console logging. Most of the time, alert isn’t used but it can be helpful to warn the user, etc.

    // This will generate a pop-up window with the "Hello, World!" text.
    alert("Hello, World!");
    
    // This will log to the console the "Hello, World!" text.
    To access the console in Firefox, do Ctrl+Shift+J
    console.log("Hello, World!");
    

    Adding Event Listeners

        Event listeners are the next most important after getting an element. They allow us to let the user click on stuff or interact through other ways in order to create dynamic interactions.

    // This attaches a click event to the entire DOM.
    // We can then check which IDs, Classes, etc were clicked to then do other things.
    
    document.addEventListener("click", (e) => {
        if(e.target.id == "alert2")
            alert("You clicked an element with the ID of alert2");
    
    });
    
    
    // This attaches to a specific element with the ID of cars and
    // when clicked alerts us to the innerHTML text.
    
    <p id="cars">Hello, World!</p>
    
    document.getElementById('cars').addEventListener("click", (e) => {
            alert("The content is:  " + e.target.innerHTML);
    });
    
    // This attaches it in a different manner.
    document.getElementById('cars').onclick =  function(){
        // do stuff
    }
    
    // You can add it though a tag as well.
    <div onclick="myFunction()"> I am clickable! </div>
    

    Here is a list of some common HTML event attributes:

    EventDescription
    onchangeAn HTML element has been changed
    onclickThe user clicks an HTML element
    onmouseoverThe user moves the mouse over an HTML element
    onmouseoutThe user moves the mouse away from an HTML element
    onkeydownThe user pushes a keyboard key
    onkeyupThe user releases a keyboard key
    onloadThe browser has finished loading the page

    Arrays

        Arrays in JavaScript are a special object and really act like lists or vectors since we can push new values to it.

    // An empty array
    var cars = [];
    
    // Has nodes/objects
    var cars = ["Toyota", "Sab", "Mazda"];
    
    // Add to array
    cars.push("Nesan');
    
    // Remove from end of array
    cars.pop();
    

    Parent Element

        Sometimes, we need to access the element that contains the element we accessed. This could be because we want to remove the element or we want to add something next to it than in it.

    <div>
        <p id="cars" >
            Cars are cool.
        </p>
    But boats are even more cool.
    </div>
    
    var x = document.getElementById('cars').parentElement;
    alert(x.innerHTML);  // This will present an alert box with "But boats are even more cool."
    
    
    // This will remove the element we accessed from the div
    var childElm = document.getElementById('cars');
    var parentElm = childElm.parentElement;
    
    parentElm.removeChild(childElm);
    

    Cookies

        Sometimes, we need to store user information for later usage. This is where cookies come in.

    function saveAsCookie() {
        var uName = document.getElementsByName("userName")[0].value;
        var eml = document.getElementsByName("email")[0].value;
    
    
        // should set expires date: Ex -> expires=(UTC date).
        // Use secure; in argument to make sure it only transports across HTTPS or secure connections
        document.cookie = "username=" + uName  +"; path=" + document.URL;
        document.cookie = "email=" + eml + "; path=" + document.URL;
    }
    
    function displayCookies() {
        var cookiesField = document.getElementById("cookieField");
        var cookies = document.cookie.split(";");  // Set as an array to traverse....
    
        for (var i=0; i<cookies.length; i++) {
            cookiesField.innerHTML += cookies[i] + "<br/>";
        }
    }
    
    function clerCookies() {
        var expireDate = "Thu, 01 Jan 1970 00:00:00 UTC";
        document.cookie = "username=; expires=" + expireDate;
        document.cookie = "email=; expires= " + expireDate;
    }
    
    <form>
    <input type="text" title="User Name" name="userName" placeholder="User Name" value=""/>
    <input type="text" title="Email" name="email" placeholder="Email" value=""/>
    <input type="button" name="submit"  onclick="saveAsCookie()" value="loginSubmit">
    </form>
    
    <button type="button" name="button" onclick="displayCookies()">Get Cookie</button>
    <button type="button" name="button" onclick="clerCookies()">Clear Cookie</button>
    
    <div id="cookieField"></div>
    

    AJAX

        AJAX is a developer’s dream, because you can:

    • Update a web page without reloading the page
    • Request data from a server – after the page has loaded
    • Receive data from a server – after the page has loaded
    • Send data to a server – in the background
    function loadDoc() {
      var xhttp = new XMLHttpRequest();        // Create the xhttp object
      xhttp.onreadystatechange = function() {  // This is actually run after open and send are done
        if (this.readyState == 4 && this.status == 200) {  // Confirm we have a  successful connection
         // Receive the response info. For PHP it is echo that sends it. Then set into demo div
         document.getElementById("demo").innerHTML = this.responseText;  
        }
      };
      xhttp.open("GET", "ajax_info.txt", true);  // post or get, path to XML page or php script, set async 
      xhttp.send();                              // Start the process
    }
    
    
    <button type="button" name="button" onclick="loadDoc()">Load XML</button>
    <div id="demo">

    String Manipulation

        String Manipulation can be important when handling cookies or data. Sometimes we need to split it into an array, make it lower case or vise versa, find a sub string, or more.
    These should get you started:

    // Find sub string
    var str = "Hello world, welcome to the universe.";
    var n = str.includes("world");
    
    // Find sub string at offset
    var str = "Hello world, welcome to the universe.";
    var n = str.includes("world", 12);
    
    // Replace string 
    var str = "Windows!";
    var res = str.replace("Windows", "Linux");  // old value, new value
    
    // Replace all case sensitive
    var str = "Mr Blue has a blue house and a blue car";
    var res = str.replace(/blue/g, "red");
    
    // Replace all case-insensitive
    var str = "Mr Blue has a blue house and a blue car";
    var res = str.replace(/blue/gi, "red");
    
    // String split
    var str = "How are you doing today?";
    var arry = str.split(" ");  // Split by spaces
    
    // To Upper
    var x = "Linux";
    x.toUpperCase();
    
    // To Lower
    var x = "LINUX";
    x.toLowerCase();
    

    Conclusion

        I think this list is pretty good and fits most user's needs. This should definitely help those who are looking for a certain tag or CSS logic or are just wanting to see a broad selection of what web technologies are based off of. Coders, website developers, Admins, etc should have most of what they need right on the page with good samples to start. Leave a commemt if you'd like me to add something else! Anyway, if you liked this reference sheet/cheat sheet, start using what you have learned by setting up a quick test server! Read my article by clicking the below image!


    Servers

    W3C Killed Web Security

    W3C Killed Web Security

    W3C Logo
    W3C Logo

        It’s a sad day folks…. The W3C killed web security by accepting DRM without having a caveat that protects against DMCA’s (Digital Millennium Copyright Act) unreasonable reach. Security researchers are out; hackers are in. While I am sure that most users believe that companies and creators have the right to protect their IP (Intellectual Property), I am also sure they believe in having strong security and a reasonable right to use their purchased product in whatever manner they see fit. With the web, it was a last bastion that held to those principles. It was killed both brutally and without much compunction by W3C and its corporate backers in a vain attempt to stem the tide of piracy and illegal copying.

        Let’s be clear here for a moment about the current problem. I don’t have an issue with DRM. I don’t agree with it all the time but neither do I disagree with it all the time. No, the issue is with DMCA and it’s unreasonable reach in trying and failing to protect DRM. There are two sections in the DMCA that are of great interest. The core section I am referring to is Section 1201: Circumvention of copyright protection systems.

        Section 1201 affects the web and all technologies the most and is why it is a sad day for the internet. The EFF letter to W3C addresses some of the concerns regarding Section 1201 in its implementation in web technologies.
    Here are some of the critical points they made when hoping W3C would add a pretext for accepting DRM standards.

        “This covenant would allow the W3C’s large corporate members to enforce their copyrights. Indeed, it kept intact every legal right to which entertainment companies, DRM vendors, and their business partners can otherwise lay claim. The compromise merely restricted their ability to use the W3C’s DRM to shut down legitimate activities, like research and modifications, that required circumvention of DRM….
        More directly, such a covenant would have helped protect the key stakeholders, present and future, who both depend on the openness of the Web, and who actively work to protect its safety and universality. It would offer some legal clarity for those who bypass DRM to engage in security research to find defects that would endanger billions of web users; or who automate the creation of enhanced, accessible video for people with disabilities; or who archive the Web for posterity. It would help protect new market entrants intent on creating competitive, innovative products, unimagined by the vendors locking down web video.”

    There is the crux of the issue and why W3C should have had clear stipulations for implementing DRM into web technologies. There really isn’t anything protecting the user and their right to circumvent DRM when it is not infringing the patent holder or IP source. Security experts are now in a quasi grey area where their work is to determine vulnerabilities but they are violating DMCA. This helps no one but the bad guys and that is just sad in the day and age where billions of users need strong security the most.

        In addition, we don’t know who did and didn’t vote in favor of the implementation of a DRM standard. The votes are secret and that should disturb us even more than the terrible overreach of DMCA’s rules. It is worth noting that W3C’s member votes aren’t always public and by default one must opt-in for public disclosure of said vote. For an organization that affects our lives, to not have public disclosure of votes by default and as enforced practice is egregious. We all know why this is the case though. Companies don’t want to look like the bad guys even when they are. So they hide in anonymity as we all are left to hang by their terrible decisions. We can make some guesses as to who voted for the standardization but don’t know who else are their accomplices. Essentially, a private group gets to affect our lives without us holding them accountable. In addition, their votes wont stop piracy or illegal copying. So all in all, they hurt themselves as well as us with nothing to show for it but the further stripping of our rights.

        While it all looks bad, there are bright spots. The US government is looking to open source its code base as much as it reasonably can. Maybe they’ll step in and decide obtrusive DRM and its protective DMCA rules are too powerful. If interested in some of their projects, check out my article covering some of the best packages released to date.

    WordPress CLI

    WordPress CLI

    WordPress CLI

        As a person who is more comfortable in a terminal environment than GUI, I love finding tools that make my life easier and more comfortable. When I started using WordPress I was often aggravated by the fact that I had to move around an interface rather than just typing up some html or a command to get a task done. Obviously, that method works well for small scale projects but less so when one is managing a lot of content and pages. WordPress just makes life easier in that respect. But I still like having lower level access and this is where WordPress CLI comes in. WordPress CLI is a command line interface for managing WordPress sites. Things like updating the core, plugins, or themes is made faster since I SSH often into my site’s box and can type up some commands quickly to do those tasks and much more. As such, I wanted to make a simple collection of commands that everyone will find useful. But first, we need to install the plugin….

    Installing WordPress CLI

        As per the sites instructions, it is extremely easy to get up and running. All one simply needs to do is download the file, chmod it, and move it to the proper location.
    To download:
    wget https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar
    OR
    curl -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar

    Next, let us make it runnable. Simply type:
    chmod +x wp-cli.phar
    Let’s make sure the file is working properly.
    php wp-cli.phar --info
    From there, we are ready to move it to its new home. Simply type:
    *Note: You might need to use sudo depending on your level of access to the server.
    mv wp-cli.phar /usr/local/bin/wp

    Using WordPress CLI

        OK, now that WordPress CLI is installed we are set to use it. The first thing to do though is cd to the WordPress directory. This is usually somewhere in /var.
    Once there, it’s time to play with some of the commands. First things first, one should know what plugins and themes are installed. To do that, simply type:
    wp plugin list && wp theme list
    This will list all the slugs associated with the plugins themes. One needs them in order to do things like disable, remove, and install them.
    Now, let us say that we got from the above commands:

    Plugins:
    +--------------------------------+----------+--------+---------+
    | name                           | status   | update | version |
    +--------------------------------+----------+--------+---------+
    | add-from-server                | active   | none   | 3.3.3   |
    | akismet                        | active   | none   | 3.3.3   |
    | backup                         | inactive | none   | 1.1.46  |
    | maintenance-mode-free          | active   | none   | 1.2     |
    +--------------------------------+----------+--------+---------+
    
    Themes
    +-----------------+----------+--------+---------+
    | name            | status   | update | version |
    +-----------------+----------+--------+---------+
    | twentyfifteen   | active   | none   | 1.8     |
    | twentyseventeen | inactive | none   | 1.3     |
    | twentysixteen   | inactive | none   | 1.3     |
    +-----------------+----------+--------+---------+
    

    We notice that Akismet is installed and know too that we are transitioning to use a different plugin to handle spam fighting. To uninstall it we do the following:
    wp plugin deactivate akismet && wp plugin delete akismet
    If we want it back, we can do the following:
    wp plugin install akismet && wp plugin activate akismet
    Now, we should update or at least check to see if there is an update needed.
    wp plugin update akismet
    The same principles are used with themes as well. Replace akismet with the theme name from the list and you get the same results but for themes. The only differences are that instead of plugin we use theme in the command and to disable a theme one needs to use the term disable rather than deactivate. Like so:
    wp theme disable twentyfifteen

    Final Thoughts

        As a final thought or two, it is worth noting how to find the slug for a plugin or theme. To do that, go to either https://wordpress.org/plugins/ or https://wordpress.org/themes/. From there, after finding something worth while, look at the end of the url to find what we need. For this example, use the plugin bbpress and look at the end of its URL: https://wordpress.org/plugins/bbpress/. Supplant that information like so:
    wp plugin install bbpress && wp plugin activate bbpress
    This will then install the plugin and activate it.
        Welp, this covers the basics and gets one started but there are other commands that are available. Simply go to their site to find them. Now that we have an new awesome tool to play with, click the image below to look at quick servers one can setup for WordPress.


    https://www.itdominator.com/quick-test-server/

    servers with a blue tinted globe

    Quick Test Server

    Quick Test Server

    Server

        There are times when I need a server in order to test some feature or bit of code. I don’t like spooling up a Linux, Apache, Mysql, and PHP (LAMP) or Linux, Nginx, Mysql, and PHP (LEMP) stack because it’s tedious. Notice what I did there? I made the whole sentence tedious to get you to think it really is tedious. It really isn’t but frankly, I needed a reason to write this. Anyway, so, what is one to do? Well, there are two option that come to mind and those are Python, Php, or Netcat. One might ask, “Whaaat? Rly?” Yup. Really. All one needs to do is open up a terminal/cli and get ta hackin.

        Python call up the Python module SimpleHTTPServer using the switch -m and then give it a port. Make the port greater than 1024 since those are reserved and require root to use. BAM! Open your browser of poison and go to localhost:portNumber or 127.0.0.1:portNumber.

    Python Server

    python -m SimpleHTTPServer 1337
    

    I did not need to insert any index.html files to the directory. Python automatically gives a list of the directory contents when no index file is found. As a side note, Python doesn’t seem to read Php properly. I have yet to get it to work.

        For Php all one does is use the switch -S and then give it an address (127.0.0.1) and port. Again, make the port greater than 1024 since those are reserved and require root to use. BAM! Once more, open your browser of poison and go to localhost:portNumber or 127.0.0.1:portNumber.

    Php Server

    php -S 127.0.0.1:1337
    

    It is worth noting that with Php I had to insert an index.php file into the directory I ran the command from. It doesn’t generate any list but does throw an error when no index is found. Additionally, this method seems to only work with Php files. To test if the Php server works, simply insert in the index.php :

    <?php
        phpinfo();
    ?>
    

        For the last one we will look at Netcat. Netcat is the swiss army knife of the networking tools and has an interesting way of creating a kind of server. To start off, simply create a file called serve.sh. The name is arbitrary but that’s what we will use for this example. Then, in the file add

    Netcat Server

    #!/bin/bash
    
        echo "`cat index.html`"
    

    When this is done, simply create an index.html as you would any other. In my case, I did:

    <!DOCTYPE html>
    <html>
    <head>
        <meta charset="utf-8">
        <title>Google Link</title>
    </head>
    <body>
        <h1><a href="http://www.google.com">Google</a></h1>
    </body>
    </html>
    

    After all this prep, which isn’t much we simply run in the terminal where serve.sh and index.html is:

    while true; \
    do { \
        echo -e 'HTTP/1.1 200 OK\r\n'; sh serve.sh; \
    } | nc -l 1337; \
    done
    

    One might need to press enter again to actually run it because of the \’s stating “look to next line for rest of command”. One can also just remove the \’s and put the whole command like so:

    while true; do { echo -e 'HTTP/1.1 200 OK\r\n'; sh serve.sh; } | nc -l 1337; done
    

    One can use Php with this by the way. All one does is rename index.html to index.php. Then one adds some code like in the Php example above. After that, in the serve.sh, edit the cat index.php to be php index.php. This has Php interpret the file which then has its output gets echoed back to the requester.
    All of this needs some explaining. So what is happening is that the while loop is checking to see if there is anything left to run. Note that the first part before the semicolon tells the browser that there is a server where one requested one. IE, it confirms the request. Then, the serve.sh is ran. In serve.sh it echos out what cat prints from index.html or what Php prints from index.php. This is essentially sent as the file back to the requester. Thus, we can see the h1 sized Google anchor link in this example.

        Voila! A nice juicy server is ready for use in any project that needs one. If one is adventurous, one can use these simple servers to serve files on the local network. To do this, all you have to do is allow the port to accept connections using UFW and then change the address “127.0.0.1” to “0.0.0.0”. This isn’t recommended for long term use but can be useful when needing to transfer something or using an app that’s for the local network. Even then, one might be better off just using ssh or email! Still, in those rare times, all one does is allow the port to be open by using ufw.

    ufw allow portNumber/tcp
    

    To remove the rule:

    ufw status numbered
    ufw delete "the number associated with ones portNumber"
    
    Schools Should Teach Kids Scripting

    Schools Should Teach Kids Scripting

        Schools should teach kids scripting. When I say kids I am thinking of those old enough to be in grades 5-8. Forget actual programming (though one may argue scripting is programming) and get them into Bash. I say Bash because it’s already installed on most major platforms with Microsoft finally coming around in Windows 10. One may ask why and the answer is simple. It is simple. There is no need to install compilers and there is no need to worry about includes or imports or whatever else others have cleverly implemented to create despair in a programmer. Not only that, it gets the core ideas of programming down. Sure, it isn’t Object Oriented Programming (OOP) but that is a minor issue when we are talking about kids. The gist of programming is understanding iterations, functions, variables, assignment, general maths, and other bits and bobs. Once these are down, it is relatively easy to learn most languages. As an example of how easy it is to get started, I will show an example that prints to the terminal screen “Hello World!” and the current user that is logged in with a separate function for each: main and showUser.

    Bash Example

    #!/bin/bash
    
    function main() {
        echo "Hello World!"; // Prints to the terminal Hello World.
        showUser;            // Calls showUser function
    }
    
    function showUser() {
        me=`whoami`;  // Runs a command and assigns the output to me
        echo $me;     // calls the variable me and prints to the terminal.
    }
    main; // Calls main function
    
    

    When in a Linux environment this can be made more advanced with simple GUIs through zenity, yad, or dialog.
    I wont show an example for those but one should get the drift.

        From the established core, one will then focus their attention on concepts like encapsulation, obfuscation, polymorphism, etc. Getting core concepts involving imperative statements and logical procedure is the hardest part. Having had my programming career start off this way makes me biased but it seems to me to be a more logical flow. Schools covering grades 9-12 should cover concepts of OOP by using Java which is a proper programming language. I advocate for Java because of its FX library and the tools that allow one to create full fledged programs. As case and point, let’s look at how easy it is to create a window with a button. To see how easy it is I will use an analogy of a play being setup.

    Java Example

    import javafx.application.Application;  // The building where the play is
    import javafx.stage.Stage;              // The stage in the building
    import javafx.scene.Scene;              // The scene of the play. Ie, are we in a city, park, house
    import javafx.scene.layout.AnchorPane;  // The confinement of the objects in the scene. Like a house or ally with walls.
    import javafx.scene.control.Button;     // The actual objects of the play. Plants, pots, food, etc.
    
    public class Main extends Application {
        @Override
        public void start(Stage stage) {
            // define what is going to be in the scene
            AnchorPane pane = new AnchorPane();    // Create the confinement of where objects go.
            Button closeBttn = new Button("Close Stage Curtain");  // Create an object for our world. A button called Close Stage Curtain.
    
            pane.getChildren().add(closeBttn);            // Add to the confinement
            Scene scene = new Scene(pane, 800, 600);      // Determin what the scene is comprised of. Ie, dogs and cats with plants?
    
            stage.setTitle("The Phantome of the Opera");  // Tell the world what play we are seeing
            stage.setResizable(false);    // Limit the stage size to what size the scene says and no more or less
            stage.setScene(scene);        // Set our scene onto the stage
            stage.show();                 // Open the curtains
    
            closeBttn.setOnAction(e -> {
                stage.close();  // Close the stage curtain
            });
        }
    
        public static void main(String[] args) { launch(args); }
    }
    

    Excluding the fluff of importing the needed libraries and calling main, one can with nine to ten meaningful commands setup a window with a proper title and a button. Not only that, the button closes the window. Amazing! I also like using the play analogy because it gives the top to bottom logic of how Java operates to setup a window. In addition, Java uses HTML and CSS for styling windows. This is awesome because it adds another useful tool were one to get further along in learning all there is to know about tech. So what are your thoughts? Should schools teach kids in this order and with these selected languages? Comment below or Message me through email.