<a href="https://getcomposer.org/" target="_blank" rel="noreferrer noopener" aria-label=" (opens in a new tab)">Composer</a> is a dependency manager for PHP (similar to npm for Node.js or pip for Python). Composer will pull in all the required PHP packages your project depends on and manage them for you.



In this tutorial, we’ll show you how to install and use Composer on an Ubuntu 18.04 machine. The same steps can be used for Ubuntu 16.04.



<h2 id="prerequisites">Prerequisites</h2>



Before continuing with this tutorial, make sure you are logged in as a&nbsp;user with sudo privileges&nbsp;and you have&nbsp;PHP installed on your Ubuntu 18.04&nbsp;system.



<h2 id="installing-php-composer">Installing PHP Composer</h2>



If you are in a hurry and you don’t want to verify the file integrity scroll down to the&nbsp;Installing Composer - Quick Way&nbsp;section.



To install Composer on your Ubuntu system, perform the following steps:



01. Before downloading and installing Composer, first update the packages index and install the necessary requirements:



<pre class="wp-block-code"><code>sudo apt update
sudo apt install wget php-cli php-zip unzip</code></pre>



02. Now that we have php cli installed on our machine, we can download the composer installer with:



<pre class="wp-block-code"><code>php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"</code></pre>



The command above will download the&nbsp;<code>composer-setup.php</code>&nbsp;file in the current working directory.



03. Next, we need to verify the data integrity of the script by comparing the script <code>SHA-384</code> hash with the latest installer hash found on the <a href="https://composer.github.io/pubkeys.html" target="_blank" rel="noreferrer noopener" aria-label=" (opens in a new tab)">Composer Public Keys / Signatures</a> page.



We will use the following&nbsp;wget command&nbsp;to download the expected signature of the latest Composer installer from the Composer’s Github page and store it in a variable named&nbsp;<code>HASH</code>:



<pre class="wp-block-code"><code>HASH="$(wget -q -O - https://composer.github.io/installer.sig)"</code></pre>



Now run the following command to verify that the installation script is not corrupted:



<pre class="wp-block-code"><code>php -r "if (hash_file('SHA384', 'composer-setup.php') === '$HASH') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"</code></pre>



If the hashes match, you will see the following output:



<pre class="wp-block-code"><code>Output:
Installer verified</code></pre>



If the hashes don’t match you will see&nbsp;<code>Installer corrupt</code>. In this case you will need to redownload the Composer installation script and double check the value of the&nbsp;<code>$HASH</code>&nbsp;variable with&nbsp;<a href="https://linuxize.com/post/echo-command-in-linux-with-examples/"><code>echo $HASH</code></a>. Once the installer is verified, you can continue with the next step.



04. The following command will install Composer in the <code>/usr/local/bin</code>directory:



<pre class="wp-block-code"><code>sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer</code></pre>



<pre class="wp-block-code"><code>Output
All settings correct for using Composer
Downloading...

Composer (version 1.8.5) successfully installed to: /usr/local/bin/composer
Use it: php /usr/local/bin/composer</code></pre>



The&nbsp;<code>composer</code>&nbsp;is installed as a system-wide command and it will be available for all users.



05. The last step is to verify the installation:



<pre class="wp-block-code"><code>$ composer</code></pre>



The command above, will print the Composer’s version, commands and arguments.



<pre class="wp-block-code"><code>Output
______
/ ____/___ ____ ___ ____ ____ ________ _____
/ / / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__ ) __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
 /_/
Composer version 1.8.5 2019-04-09 17:46:47

Usage:
 command [options] [arguments]</code></pre>

Composer is a dependency manager for PHP (similar to npm for Node.js or pip for Python). Composer will pull in all the required PHP packages your...

How To Install and Use PHP Composer on Ubuntu 16/18/19 - TCMHACK

How To Install and Use PHP Composer on Ubuntu 16/18/19

In the web application, generally, the file is downloaded from the same server. But sometimes the file needs to be downloaded from the remote server. To download file with PHP, you need to force the browser to download the file.&nbsp;<a href="/how-to-force-download-file-in-php/">Force download in PHP</a>&nbsp;helps to download file from the server and save to the local drive.

In the example code snippet, we will show you how to force download file from URL in PHP. You can download any types of file (image, ZIP, video, audio, etc) from the remote server using PHP.

Use the&nbsp;readfile()&nbsp;function with&nbsp;<code>application/x-file-to-save</code>&nbsp;Content-type&nbsp;header, to download a ZIP file from remote URL using PHP.
<pre>//&nbsp;Remote&nbsp;download&nbsp;URL
$remoteURL&nbsp;=&nbsp;'https://www.example.com/files/project.zip';

//&nbsp;Force&nbsp;download
header("Content-type:&nbsp;application/x-file-to-save");&nbsp;
header("Content-Disposition:&nbsp;attachment;&nbsp;filename=".basename($remoteURL));
ob_end_clean();
readfile($remoteURL);
exit;</pre>
Note that: The&nbsp;ob_end_clean()&nbsp;function will help to download a large file from the remote server in PHP.

In the web application, generally, the file is downloaded from the same server. But sometimes the file needs to be downloaded from the remote ser...

How to Force Download File from Remote Server in PHP - TCMHACK

How to Force Download File from Remote Server in PHP

To download a file in PHP, you need to force the browser to download file except display. In this article, we are going to show how to download a file from directory or server in PHP. Using&nbsp;<code>header()</code>&nbsp;and&nbsp;<code>readfile()</code>&nbsp;function, you can easily download a file in PHP. Here we’ll provide the example PHP code to force download file in PHP. Also, this simple PHP script helps to implement a download link which downloads a file from the directory. The following example script can be used for download any types of file like text, image, document, pdf, zip, etc.
<h2>Download a File in PHP</h2>
<pre>$fileName = basename('tcmhack.txt');
$filePath&nbsp;=&nbsp;'files/'.$fileName;
if(!empty($fileName)&nbsp;&amp;&amp;&nbsp;file_exists($filePath)){
&nbsp;&nbsp;&nbsp;&nbsp;//&nbsp;Define&nbsp;headers
&nbsp;&nbsp;&nbsp;&nbsp;header("Cache-Control:&nbsp;public");
&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Description:&nbsp;File&nbsp;Transfer");
&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Disposition:&nbsp;attachment;&nbsp;filename=$fileName");
&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Type:&nbsp;application/zip");
&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Transfer-Encoding:&nbsp;binary");
&nbsp;&nbsp;&nbsp;&nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;//&nbsp;Read&nbsp;the&nbsp;file
&nbsp;&nbsp;&nbsp;&nbsp;readfile($filePath);
&nbsp;&nbsp;&nbsp;&nbsp;exit;
}else{
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'The&nbsp;file&nbsp;does&nbsp;not&nbsp;exist.';
}</pre>
<h2>Download a File Through Anchor Link</h2>
Sometimes you need to provide a link to the user for download file from the server. Use the below sample code to display an HTML link to download a file from the directory using PHP.
HTML Code:
<pre>&lt;a href="download.php?file=tcmhack.png"&gt;Dowload File&lt;/a&gt;
</pre>
PHP Code (download.php):
<pre>&lt;?php
if(!empty($_GET['file'])){
&nbsp;&nbsp;&nbsp;&nbsp;$fileName&nbsp;=&nbsp;basename($_GET['file']);
&nbsp;&nbsp;&nbsp;&nbsp;$filePath&nbsp;=&nbsp;'files/'.$fileName;
&nbsp;&nbsp;&nbsp;&nbsp;if(!empty($fileName)&nbsp;&amp;&amp;&nbsp;file_exists($filePath)){
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;//&nbsp;Define&nbsp;headers
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;header("Cache-Control:&nbsp;public");
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Description:&nbsp;File&nbsp;Transfer");
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Disposition:&nbsp;attachment;&nbsp;filename=$fileName");
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Type:&nbsp;application/zip");
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;header("Content-Transfer-Encoding:&nbsp;binary");
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;//&nbsp;Read&nbsp;the&nbsp;file
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;readfile($filePath);
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;exit;
&nbsp;&nbsp;&nbsp;&nbsp;}else{
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'The&nbsp;file&nbsp;does&nbsp;not&nbsp;exist.';
&nbsp;&nbsp;&nbsp;&nbsp;}
}</pre>

To download a file in PHP, you need to force the browser to download file except display. In this article, we are going to show how to download a...

How to Force Download File in PHP - TCMHACK

How to Force Download File in PHP

Before taking any action with date input, it always a great idea to validate the date string. Date validation helps to check whether the provided string is a valid date format. Using the DateTime class you can easily check if the date string is valid in PHP.

In the example code snippet, we will show you how to validate a date string in PHP. It is very useful for server-side validation of the date input using PHP.

The&nbsp;validateDate()&nbsp;function checks whether the given string is a valid date using PHP. It uses PHP DateTime class to validate date based on the specified format. This function returns TRUE if date string is valid, otherwise FALSE.
<ul class="bullet_disk_list">
 	<li><code>$date</code>&nbsp;– Required. The date string to validate.</li>
 	<li><code>$format</code>&nbsp;– Optional. The format of the date string.</li>
</ul>
<pre>function&nbsp;validateDate($date,&nbsp;$format&nbsp;=&nbsp;'Y-m-d'){
&nbsp;&nbsp;&nbsp;&nbsp;$d&nbsp;=&nbsp;DateTime::createFromFormat($format,&nbsp;$date);
&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;$d&nbsp;&amp;&amp;&nbsp;$d-&gt;format($format)&nbsp;===&nbsp;$date;
}</pre>
Call the&nbsp;<code>validateDate()</code>&nbsp;function and pass the date string in the first parameter.
<pre>//&nbsp;Returns&nbsp;false
var_dump(validateDate('2018-14-01'));&nbsp;
var_dump(validateDate('20122-14-01'));
var_dump(validateDate('2018-10-32'));
var_dump(validateDate('2017-5-25'));

//&nbsp;Returns&nbsp;true
var_dump(validateDate('2018-12-01'));
var_dump(validateDate('1970-11-28'));</pre>
By default, the format is set to&nbsp;<code>Y-m-d</code>. If you want to allow day and month without leading zeroes, specify the respective format (<code>Y-n-j</code>).
<pre>//&nbsp;Returns&nbsp;true
var_dump(validateDate('2018-2-5',&nbsp;'Y-n-j'));</pre>

Before taking any action with date input, it always a great idea to validate the date string. Date validation helps to check whether the provided...

How to Validate Date String in PHP - TCMHACK

How to Validate Date String in PHP

The Regular Expressions are the easiest option to change the characters format based on the specific pattern. You can change the word format in a string using PHP with Regex. In the example code snippet, we will show you how to insert space before capital letter in a string using PHP.

Sometimes the words are bunched together in a string, and you want to separate the words with spaces. In this case, you need to put a space in front of each word for differentiating the words in the string. Using the PHP preg_replace() function, you can add space in front of uppercase character in a string.

The following code separates the words by spaces and inserts space before the capital letter in a string using&nbsp;preg_replace() in PHP.
<pre>$string = 'TcmHackWebsite';
$words&nbsp;=&nbsp;preg_replace('/(?&lt;!\&nbsp;)[A-Z]/',&nbsp;'&nbsp;$0',&nbsp;$string);</pre>
Output:
<pre>Tcm Hack Website</pre>

The Regular Expressions are the easiest option to change the characters format based on the specific pattern. You can change the word format in a...

How to Insert Space Before Capital Letters in a String using PHP - TCMHACK

How to Insert Space Before Capital Letters in a String using PHP

When the user provides their account password, it always recommended validating the input. Password strength validation is very useful to check whether the password is strong. Strong password makes the user’s account secure and helps to prevent account hack.

Using Regex (Regular Expression), you can easily validate the password strength in PHP. In the example code, we will show you how to check password strength and validate a strong password in PHP using Regex.

The following code snippet, validate the password using&nbsp;preg_match() function in PHP&nbsp;with Regular Expression, to check whether it is strong and difficult to guess.
<ul class="bullet_disk_list">
 	<li>Password must be at least 8 characters in length.</li>
 	<li>Password must include at least one upper case letter.</li>
 	<li>Password must include at least one number.</li>
 	<li>Password must include at least one special character.</li>
</ul>
<pre>//&nbsp;Given&nbsp;password
$password&nbsp;=&nbsp;'user-input-pass';

//&nbsp;Validate&nbsp;password&nbsp;strength
$uppercase&nbsp;=&nbsp;preg_match('@[A-Z]@',&nbsp;$password);
$lowercase&nbsp;=&nbsp;preg_match('@[a-z]@',&nbsp;$password);
$number&nbsp;&nbsp;&nbsp;&nbsp;=&nbsp;preg_match('@[0-9]@',&nbsp;$password);
$specialChars&nbsp;=&nbsp;preg_match('@[^\w]@',&nbsp;$password);

if(!$uppercase&nbsp;||&nbsp;!$lowercase&nbsp;||&nbsp;!$number&nbsp;||&nbsp;!$specialChars&nbsp;||&nbsp;strlen($password)&nbsp;&lt;&nbsp;8)&nbsp;{
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'Password&nbsp;should&nbsp;be&nbsp;at&nbsp;least&nbsp;8&nbsp;characters&nbsp;in&nbsp;length&nbsp;and&nbsp;should&nbsp;include&nbsp;at&nbsp;least&nbsp;one&nbsp;upper&nbsp;case&nbsp;letter,&nbsp;one&nbsp;number,&nbsp;and&nbsp;one&nbsp;special&nbsp;character.';
}else{
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'Strong&nbsp;password.';
}</pre>

When the user provides their account password, it always recommended validating the input. Password strength validation is very useful to check w...

How to Validate Password Strength in PHP - TCMHACK

How to Validate Password Strength in PHP

Stripping query parameter is very useful when you want to create a URL dynamically based on some conditions. The preg_replace() function is the easiest way to remove a specific parameter and its value from URL query string using PHP. PHP preg_replace() function searches string for matches to pattern and replace with the replacement. Use preg_replace() with REGEX to remove parameter from query string using PHP.

In the following code snippet shows how you can remove specific query string variable from URL in PHP.
<pre>$key&nbsp;=&nbsp;'page';
$url = 'http://ec2-13-127-91-65.ap-south-1.compute.amazonaws.com/?type=product&amp;page=5';

//&nbsp;Remove&nbsp;specific&nbsp;parameter&nbsp;from&nbsp;query&nbsp;string
$filteredURL&nbsp;=&nbsp;preg_replace('~(\?|&amp;)'.$key.'=[^&amp;]*~',&nbsp;'$1',&nbsp;$url);</pre>
The following example code shows how you can remove a specific parameter from the query string of the current URL using PHP.
<pre>$protocol&nbsp;=&nbsp;((!empty($_SERVER['HTTPS'])&nbsp;&amp;&amp;&nbsp;$_SERVER['HTTPS']&nbsp;!=&nbsp;'off')&nbsp;||&nbsp;$_SERVER['SERVER_PORT']&nbsp;==&nbsp;443)&nbsp;?&nbsp;"https://"&nbsp;:&nbsp;"http://";
$currentURL&nbsp;=&nbsp;$protocol&nbsp;.&nbsp;$_SERVER['HTTP_HOST']&nbsp;.&nbsp;$_SERVER['REQUEST_URI'];

$key&nbsp;=&nbsp;'page';

//&nbsp;Remove&nbsp;specific&nbsp;parameter&nbsp;from&nbsp;query&nbsp;string
$filteredURL&nbsp;=&nbsp;preg_replace('~(\?|&amp;)'.$key.'=[^&amp;]*~',&nbsp;'$1',&nbsp;$currentURL);</pre>

Stripping query parameter is very useful when you want to create a URL dynamically based on some conditions. The preg_replace() function is the e...

How to Remove a Specific Parameter from URL Query String using PHP - TCMHACK

How to Remove a Specific Parameter from URL Query String using PHP

The file_exists() function in PHP, is used to check if a file or directory exists on the server. But the file_exists() function will not usable if you want to check the file existence on the remote server. The fopen() function is the easiest solution to check if a file URL exists on a remote server using PHP.

The following code snippet show you how to&nbsp;check if remote file exists&nbsp;using fopen() function in PHP.
<pre>//&nbsp;Remote&nbsp;file&nbsp;url
$remoteFile&nbsp;=&nbsp;'https://www.example.com/files/project.zip';

//&nbsp;Open&nbsp;file
$handle&nbsp;=&nbsp;@fopen($remoteFile,&nbsp;'r');

//&nbsp;Check&nbsp;if&nbsp;file&nbsp;exists
if(!$handle){
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'File&nbsp;not&nbsp;found';
}else{
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'File&nbsp;exists';
}</pre>
You can also use cURL to check if a URL exists on the remote server. The following code snippet show you how to&nbsp;check if remote file URL exists&nbsp;using cURL in PHP.
<pre>//&nbsp;Remote&nbsp;file&nbsp;url
$remoteFile&nbsp;=&nbsp;'https://www.example.com/files/project.zip';

//&nbsp;Initialize&nbsp;cURL
$ch&nbsp;=&nbsp;curl_init($remoteFile);
curl_setopt($ch,&nbsp;CURLOPT_NOBODY,&nbsp;true);
curl_exec($ch);
$responseCode&nbsp;=&nbsp;curl_getinfo($ch,&nbsp;CURLINFO_HTTP_CODE);
curl_close($ch);

//&nbsp;Check&nbsp;the&nbsp;response&nbsp;code
if($responseCode&nbsp;==&nbsp;200){
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'File&nbsp;exists';
}else{
&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;'File&nbsp;not&nbsp;found';
}</pre>

The file_exists() function in PHP, is used to check if a file or directory exists on the server. But the file_exists() function will not usable i...

How to Check if Remote File Exists using PHP - TCMHACK

How to Check if Remote File Exists using PHP

Saving image from URL is very useful when you want to copy an image dynamically from the remote server and store in the local server.



The file_get_contents() and file_put_contents() provides an easiest way to save remote image to local server using PHP. The image file can be saved straight to directory from the URL. In the example code snippet, we will provide two ways to save image from URL&nbsp;using PHP.



<h2>Save Image from URL using PHP</h2>



The following code snippet helps you to copy an image file from remote URL and save in a folder using PHP.



<ul class="bullet_disk_list"><li>file_get_contents()&nbsp;– This function is used to read the image file from URL and return the content as a string.</li><li>file_put_contents()&nbsp;– This function is used to write remote image data to a file.</li></ul>



<pre class="wp-block-code"><code>// Remote image URL
$url = 'http://www.example.com/remote-image.png';

// Image path
$img = 'images/tcmhack.png';

// Save image&nbsp;
file_put_contents($img, file_get_contents($url));</code></pre>



<h2>Save Image from URL using cURL</h2>



You can use cURL to save an image from URL using PHP. The following code snippet helps you to copy an image file from URL using cURL in PHP.



<pre class="wp-block-code"><code>// Remote image URL
$url = 'http://www.example.com/remote-image.png';

// Image path
$img = 'images/tcmhack.png';

// Save image
$ch = curl_init($url);
$fp = fopen($img, 'wb');
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec($ch);
curl_close($ch);
fclose($fp);</code></pre>



That's it, Your file must be saved to that desired location.



 If you're still facing difficulities in saving the files, feel free to post a comment. We will try our best to solve the issue.

Saving image from URL is very useful when you want to copy an image dynamically from the remote server and store in the local server.



The file...