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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
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<meta name="author" content="Apostolos rootApostolos@swarmlab.io">
<title>An Introduction to Linux !</title>
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<body class="article toc2 toc-right">
<div id="header">
<h1>An Introduction to Linux !</h1>
<div class="details">
<span id="author" class="author">Apostolos rootApostolos@swarmlab.io</span><br>
</div>
<div id="toc" class="toc2">
<div id="toctitle">Table of contents</div>
<ul class="sectlevel1">
<li><a href="#_absolute_basics">1. Absolute basics</a>
<ul class="sectlevel2">
<li><a href="#_key_combinations">1.1. Key combinations</a></li>
<li><a href="#_ls_l">1.2. ls -l</a>
<ul class="sectlevel3">
<li><a href="#_file_types">1.2.1. File types</a></li>
<li><a href="#_access_rights">1.2.2. Access rights</a></li>
<li><a href="#_user_group_codes">1.2.3. User group codes</a></li>
<li><a href="#_exercises">1.2.4. Exercises</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="#_linux_file_system_layout">2. Linux file system layout</a></li>
<li><a href="#_find_and_grep">3. Find and grep</a>
<ul class="sectlevel2">
<li><a href="#_find">3.1. find</a></li>
<li><a href="#_grep">3.2. grep</a></li>
<li><a href="#_find_and_grep_command_together">3.3. find and grep command together</a></li>
</ul>
</li>
<li><a href="#_managing_software">4. Managing software</a>
<ul class="sectlevel2">
<li><a href="#_apt">4.1. APT</a>
<ul class="sectlevel3">
<li><a href="#_updating_package_database">4.1.1. Updating Package Database</a></li>
<li><a href="#_upgrading_package_database">4.1.2. Upgrading Package Database</a></li>
<li><a href="#_search_for_packages_with_apt">4.1.3. SEARCH FOR PACKAGES WITH APT</a></li>
<li><a href="#_installing_new_packages">4.1.4. INSTALLING NEW PACKAGES</a></li>
<li><a href="#_removing_installed_packages">4.1.5. REMOVING INSTALLED PACKAGES</a></li>
<li><a href="#_clean_up_any_unused_libraries_and_packages">4.1.6. clean up any unused libraries and packages</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="content">
<div id="preamble">
<div class="sectionbody">
<div class="paragraph">
<p><br></p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
<div class="title">NOTE</div>
<div class="paragraph">
<p>Assuming you&#8217;re already logged in</p>
</div>
</td>
</tr>
</table>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_absolute_basics">1. Absolute basics</h2>
<div class="sectionbody">
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 1. Absolute basics</caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Command</th>
<th class="tableblock halign-left valign-top">Meaning</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">ls</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Displays a list of files in the current working directory.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">cd directory</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">change directories</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">passwd</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">change the password for the current user</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">file filename</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">display file type of file with name filename</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">cat textfile</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">throws content of textfile on the screen</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">pwd</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">display present working directory</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">exit or logout</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">leave this session</p></td>
</tr>
</tbody>
<tfoot>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">man command</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">read man pages on command</p></td>
</tr>
</tfoot>
</table>
<div class="sect2">
<h3 id="_key_combinations">1.1. Key combinations</h3>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 2. Key combinations</caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Key or key combination</th>
<th class="tableblock halign-left valign-top">Function</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Ctrl+C</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">End a running program and return the prompt</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Ctrl+Z</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Suspend a program</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">ArrowUp and ArrowDown</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Browse history. Go to the line that you want to repeat, edit details if necessary, and press Enter to save time.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Tab</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Command or filename completion; when multiple choices are possible, the system will either signal with an audio or visual bell, or, if too many choices are possible, ask you if you want to see them all.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Tab Tab</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Shows file or command completion possibilities.</p></td>
</tr>
</tbody>
<tfoot>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">Shift+PageUp and Shift+PageDown</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Browse terminal buffer (to see text that has "scrolled off" the screen).</p></td>
</tr>
</tfoot>
</table>
</div>
<div class="sect2">
<h3 id="_ls_l">1.2. ls -l</h3>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash"># ls -al
drwxrwxr-x 4 zeus zeus 4096 Οκτ 23 21:55 .
drwxrwxr-x 9 zeus zeus 4096 Οκτ 15 14:28 ..
drwxrwxr-x 8 zeus zeus 4096 Οκτ 23 21:55 .git
drwxrwxr-x 4 zeus zeus 4096 Οκτ 14 20:24 install
crw------- 1 root root 5, 1 Οκτ 23 21:22 console
lrwxrwxrwx 1 root root 11 Οκτ 23 21:21 core -&gt; /proc/kcore
drwxr-xr-x 4 root root 100 Οκτ 23 21:22 cpu
crw------- 1 root root 10, 59 Οκτ 23 21:21 cpu_dma_latency
crw------- 1 root root 10, 203 Οκτ 23 21:21 cuse
-rw-rw-r-- 1 zeus zeus 1517 Οκτ 23 21:55 INSTALL.md
-rw-rw-r-- 1 zeus zeus 33883 Οκτ 15 14:28 LICENSE
-rw-rw-r-- 1 zeus zeus 691 Οκτ 17 11:13 README.md</code></pre>
</div>
</div>
<div class="sect3">
<h4 id="_file_types">1.2.1. File types</h4>
<div class="paragraph">
<p>This table gives an overview of the characters determining the file type:</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
<strong>d</strong>rwxrwxr-x 4 zeus zeus 4096 Οκτ 14 20:24 install
</td>
</tr>
</table>
</div>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 3. File types in a long list</caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Symbol</th>
<th class="tableblock halign-left valign-top">Meaning</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">-</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Regular file</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">d</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Directory</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">l</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Link</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">c</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Special file</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">s</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Socket</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">p</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Named pipe</p></td>
</tr>
</tbody>
<tfoot>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">b</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Block device</p></td>
</tr>
</tfoot>
</table>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
-<strong>rw-</strong>rw-r-- 1 zeus zeus 1517 Οκτ 23 21:55 INSTALL.md
</td>
</tr>
</table>
</div>
</div>
<div class="sect3">
<h4 id="_access_rights">1.2.2. Access rights</h4>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 4. Access rights</caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Code</th>
<th class="tableblock halign-left valign-top">Meaning</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">0 or -</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">The access right that is supposed to be on this place is not granted.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">4 or</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">read access is granted to the user category defined in this place</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">2 or</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">write permission is granted to the user category defined in this place</p></td>
</tr>
</tbody>
<tfoot>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">1 or</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">execute permission is granted to the user category defined in this place</p></td>
</tr>
</tfoot>
</table>
</div>
<div class="sect3">
<h4 id="_user_group_codes">1.2.3. User group codes</h4>
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 5. User group codes</caption>
<colgroup>
<col style="width: 33.3333%;">
<col style="width: 33.3333%;">
<col style="width: 33.3334%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Code</th>
<th class="tableblock halign-left valign-top">Meaning</th>
<th class="tableblock halign-left valign-top"></th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">u</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">user permissions</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">-<strong>rw-</strong>rw-r--</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">g</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">group permissions</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">-rw-<strong>rw-</strong>r--</p></td>
</tr>
</tbody>
<tfoot>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">o</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">permissions for others</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">-rw-rw-<strong>rw-</strong></p></td>
</tr>
</tfoot>
</table>
</div>
<div class="sect3">
<h4 id="_exercises">1.2.4. Exercises</h4>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">touch example
chmod 400 example
ls -l example
chmod 500 example
ls -l example
chmod 600 example
ls -l example
chmod 644 example
ls -l example
chmod 660 example
ls -l example
chmod 700 example
ls -l example
chmod 755 example
ls -l example
chmod 775 example
ls -l example
ls -l example
chmod 777 example
ls -l example</code></pre>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_linux_file_system_layout">2. Linux file system layout</h2>
<div class="sectionbody">
<table class="tableblock frame-all grid-all stretch">
<caption class="title">Table 6. Subdirectories of the root directory</caption>
<colgroup>
<col style="width: 50%;">
<col style="width: 50%;">
</colgroup>
<thead>
<tr>
<th class="tableblock halign-left valign-top">Directory</th>
<th class="tableblock halign-left valign-top">Content</th>
</tr>
</thead>
<tbody>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/bin</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Common programs, shared by the system, the system administrator and the users.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/boot</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">The startup files and the kernel, vmlinuz. In some recent distributions also grub data. Grub is the GRand Unified Boot loader and is an attempt to get rid of the many different boot-loaders we know today.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/dev</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Contains references to all the CPU peripheral hardware, which are represented as files with special properties.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/etc</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Most important system configuration files are in /etc</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/home</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Home directories of the common users.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/lib</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Library files, includes files for all kinds of programs needed by the system and the users.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/mnt</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Standard mount point for external file systems, e.g. a CD-ROM or a digital camera.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/opt</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Typically contains extra and third party software.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/proc</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">A virtual file system containing information about system resources.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/root</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">The administrative user&#8217;s home directory. Mind the difference between /, the root directory and /root, the home directory of the root user.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/sbin</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Programs for use by the system and the system administrator.</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/tmp</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Temporary space for use by the system, cleaned upon reboot, so don&#8217;t use this for saving any work!</p></td>
</tr>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/usr</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Programs, libraries, documentation etc. for all user-related programs.</p></td>
</tr>
</tbody>
<tfoot>
<tr>
<td class="tableblock halign-left valign-top"><p class="tableblock">/var</p></td>
<td class="tableblock halign-left valign-top"><p class="tableblock">Storage for all variable files and temporary files created by users, such as log files, the mail queue, the print spooler area, space for temporary storage of files downloaded from the Internet, or to keep an image of a CD before burning it.</p></td>
</tr>
</tfoot>
</table>
</div>
</div>
<div class="sect1">
<h2 id="_find_and_grep">3. Find and grep</h2>
<div class="sectionbody">
<div class="sect2">
<h3 id="_find">3.1. find</h3>
<div class="paragraph">
<p>The find tool, known from UNIX, is very powerful. This command not only allows you to search file names, it can also accept file size, date of last change and other file properties as criteria for a search.</p>
</div>
<div class="paragraph">
<p>The most common use is for finding file names:</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
find &lt;path&gt; -name &lt;searchstring&gt;
</td>
</tr>
</table>
</div>
<div class="paragraph">
<p>This can be interpreted as "Look in all files and subdirectories contained in a given path, and print the names of the files containing the search string in their name" <strong>(not in their content).</strong></p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash"> find /etc -name "*.conf"</code></pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="_grep">3.2. grep</h3>
<div class="paragraph">
<p>grep is used for filtering input lines and returning certain patterns to the output.</p>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
grep "string" path/to/file
</td>
</tr>
</table>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash"> grep "root" /etc/passwd</code></pre>
</div>
</div>
</div>
<div class="sect2">
<h3 id="_find_and_grep_command_together">3.3. find and grep command together</h3>
<div class="paragraph">
<p>find /etc -name "*.conf" -exec grep -Hns "conf" {} \;</p>
</div>
<div class="listingblock">
<div class="title">Explanation</div>
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">-H, --with-filename
Print the filename for each match
-n, --line-number
Prefix each line of output with the 1-based line number within its input file
-s, --no-messages
Suppress error messages about nonexistent or unreadable files.</code></pre>
</div>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
This can be interpreted as<br>
- "Look for *.conf files and subdirectories contained in /etc, and <strong>if true</strong> exec <strong>grep -Hns conf</strong> in the given file"
</td>
</tr>
</table>
</div>
<div class="admonitionblock tip">
<table>
<tr>
<td class="icon">
<i class="fa icon-tip" title="Tip"></i>
</td>
<td class="content">
Very powerful in bash scripts
create a file test.sh
.bash script
</td>
</tr>
</table>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">#!/bin/bash
STRING=$(find /etc -name "*.conf" -exec grep -Hns "conf" {} \;)
echo $STRING</code></pre>
</div>
</div>
<div class="paragraph">
<p>exec it
.bash script</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">chmod 700 test.sh
./test.sh</code></pre>
</div>
</div>
</div>
</div>
</div>
<div class="sect1">
<h2 id="_managing_software">4. Managing software</h2>
<div class="sectionbody">
<div class="sect2">
<h3 id="_apt">4.1. APT</h3>
<div class="paragraph">
<p>WHAT IS APT?</p>
</div>
<div class="paragraph">
<p>A packaging system simply provides programs and applications for installation.</p>
</div>
<div class="paragraph">
<p>APT(Advanced Package Tool) is a command line tool that is the most efficient and preferred way of managing software from the command line for Debian and Debian based Linux distributions like Ubuntu . It manages dependencies effectively, maintains large configuration files and properly handles upgrades and downgrades to ensure system stability.</p>
</div>
<div class="sect3">
<h4 id="_updating_package_database">4.1.1. Updating Package Database</h4>
<div class="paragraph">
<p>Before commencing any operations with apt, we need to ensure that our local copy of the database is up-to-date.
Without this the system won’t know if there are newer packages available or not.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">apt-get update</code></pre>
</div>
</div>
</div>
<div class="sect3">
<h4 id="_upgrading_package_database">4.1.2. Upgrading Package Database</h4>
<div class="paragraph">
<p>Once your package database has been updated, you can now upgrade the packages with updates installed on you machine. This will update any applications, and the Ubuntu core system to the latest versions available.</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">sudo apt-get upgrade</code></pre>
</div>
</div>
</div>
<div class="sect3">
<h4 id="_search_for_packages_with_apt">4.1.3. SEARCH FOR PACKAGES WITH APT</h4>
<div class="paragraph">
<p>To search for a package you can use the following command:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">apt search apache2</code></pre>
</div>
</div>
</div>
<div class="sect3">
<h4 id="_installing_new_packages">4.1.4. INSTALLING NEW PACKAGES</h4>
<div class="paragraph">
<p>If you are find the name of the package you want to install, you can install it by running this command:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">apt install apache2 vlc</code></pre>
</div>
</div>
</div>
<div class="sect3">
<h4 id="_removing_installed_packages">4.1.5. REMOVING INSTALLED PACKAGES</h4>
<div class="paragraph">
<p>To uninstall a package from your system, you can use the following command:</p>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">apt remove vlc</code></pre>
</div>
</div>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
This command removes the package but keeps the configuration files. So in case you reinstall the same package, your configuration remains the same. If you want to remove both the package and its associated configuration files, you can run this command:
</td>
</tr>
</table>
</div>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">apt purge vlc</code></pre>
</div>
</div>
</div>
<div class="sect3">
<h4 id="_clean_up_any_unused_libraries_and_packages">4.1.6. clean up any unused libraries and packages</h4>
<div class="listingblock">
<div class="content">
<pre class="highlightjs highlight"><code class="language-bash hljs" data-lang="bash">apt autoremove</code></pre>
</div>
</div>
<div class="paragraph">
<p>This command automatically removes any packages that aren’t used or associated with any installed program. It’s a great way to clean up any unused libraries and packages you don’t need.</p>
</div>
<div class="paragraph">
<p><br>
<br>
</p>
</div>
<hr>
<div class="admonitionblock note">
<table>
<tr>
<td class="icon">
<i class="fa icon-note" title="Note"></i>
</td>
<td class="content">
<div class="title">Reminder</div>
<div class="paragraph">
<p>Caminante, no hay camino,<br>
se hace camino al andar.</p>
</div>
<div class="paragraph">
<p>Wanderer, there is no path,<br>
the path is made by walking.</p>
</div>
<div class="paragraph">
<p><strong>Antonio Machado</strong> Campos de Castilla</p>
</div>
</td>
</tr>
</table>
</div>
</div>
</div>
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