Tools

Posts

Calibre Web with Docker and NGINX

Seting up your own Calibre Web server

How to Build a website With Hugo

Guide for setting up a static website with Hugo

How to Process Bookfusion Highlights with Vim

Removing extra stuff from Bookfusion exported highlights

How to Set Up Hugo Relearn Theme

Hugo Relearn setup guide

You Need to Learn Man Pages

Guide to using Man Pages

Calibre Web with Docker and NGINX

I couldn’t find a guide on how to set up Calibre web step-by-step as a Docker container. Especially not one that used Nginx as a reverse proxy.

The good news is that it is really fast and simple. You’ll need a few tools to get this done:

A server with a public IP address
A DNS Provider (I use CloudFlare)
Docker
Nginx
A Calibre Library
Certbot
Rsync

First, sync your local Calibre library to a folder on your server:

rsync -avuP your-library-dir root@example.org:/opt/calibre/

Install Docker

sudo apt update  
sudo apt install docker.io

Create a Docker network

sudo docker network create calibre_network

Create a Docker volume to store Calibre Web data

sudo docker volume create calibre_data

Pull the Calibre Web Docker image

sudo docker pull linuxserver/calibre-web

Start the Calibre Web Docker container

sudo docker run -d \   
--name=calibre-web \   
--restart=unless-stopped \   
-p 8083:8083 \   
-e PUID=$(id -u) \   
-e PGID=$(id -g) \   
-v calibre_data:/config \   
-v /opt/calibre/Calibre:/books \   
--network calibre_network \   
linuxserver/calibre-web

Configure Nginx to act as a reverse proxy for Calibre Web

Create the site file

sudo vim /etc/nginx/sites-available/calibre-web

Add the following to the file

server { listen 80;   
server_name example.com; # Replace with your domain or server IP location /   
{   
proxy_pass http://localhost:8083;   
proxy_set_header Host $host;   
proxy_set_header X-Real-IP $remote_addr;   
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;   
proxy_set_header X-Forwarded-Proto $scheme;   
} }

Enable the site

sudo ln -s /etc/nginx/sites-available/calibre-web /etc/nginx/sites-enabled/

Restart Nginx

sudo service nginx restart

DNS CNAME Record

Make sure to set up a cname record for your site with your DNS provider such as: calibre.example.com

SSL Certificate

Install ssl cert using certbot

certbot --nginx

Site Setup

Head to the site at https://calibre.example.com and log in with default credentials:

username: admin password: admin123

Select /books as the library directory. Go into admin settings and change your password.

Adding new books

Whenever you add new books to your server via the rsync command from earlier, you will need to restart the Calibre Web Docker container. Then restart Nginx.

sudo docker restart calibre-web  
systemctl restart nginx

That’s all there is to it. Feel free to reach out if you have issues.

How to Build a website With Hugo

Word Press is great, but it is probably a lot more bloated then you need for a personal website. Enter Hugo, it has less server capacity and storage needs than Word Press. Hugo is a static site generator than takes markdown files and converts them to html.

Hosting your own website is also a lot cheaper than having a provider like Bluehost do it for you. Instead of $15 per month, I am currently paying $10 per year.

This guide will walk through building a website step-by-step.

Setting up a Virtual Private Server (VPS)
Registering a domain name
Pointing the domain to your server
Setting up hugo on your local PC
Syncing your Hugo generate site with your server
Using nginx to serve your site
Enable http over SSL

Setting up a Virtual Private Server (VPS)

I use Vultr as my VPS. When I signed up they had a $250 credit towards a new account. If you select the cheapest server (you shouldn’t need anything else for a basic site) that comes out to about $6 a month. Of course the $250 credit goes towards that which equates to around 41 months free.

Head to vultr.com. Create and account and Select the Cloud Compute option.

Under CPU & Storage Technology, select “Regular Performance”. Then under “Server Location, select the server closest to you. Or closest to where you think your main audience will be.

Under Server image, select the OS you are most comfortable with. This guide uses Debian.

Under Server Size, slect the 10GB SSD. Do not select the “IPv6 ONLY” option. Leave the other options as default and enter your server hostname.

On the products page, click your new server. You can find your server credentials and IPv4 address here. You will need these to log in to your server.

Log into your sever via ssh to test. From a Linux terminal run:

ssh username@serveripaddress

Then, enter your password when prompted.

Registering a Domain Name

I got my domain perfectdarkmode.com from Cloudflare.com for about $10 per year. You can check to see available domains there. You can also check https://www.namecheckr.com/ to see iof that name is available on various social media sites.

In CloudFlare, just click “add a site” and pick a domain that works for you. Next, you will need your server address from earlier.

Under domain Registration, click “Manage Domains”, click “manage” on your domain. One the sidebar to the right, there is a qucik actions menu. Click “update DNS configuration”.

Click “Add record”. Type is an “A” record. Enter the name and the ip address that you used earlier for your server. Uncheck “Proxy Status” and save.

You can check to see if your DNS has updated on various DNS severs at https://dnschecker.org/. Once those are up to date (after a couple minutes) you should be able to ping your new domain.

$ ping perfectdarkmode.com
PING perfectdarkmode.com (104.238.140.131) 56(84) bytes of data.
64 bytes from 104.238.140.131.vultrusercontent.com (104.238.140.131): icmp_seq=1 ttl=53 time=33.2 ms
64 bytes from 104.238.140.131.vultrusercontent.com (104.238.140.131): icmp_seq=2 ttl=53 time=28.2 ms
64 bytes from 104.238.140.131.vultrusercontent.com (104.238.140.131): icmp_seq=3 ttl=53 time=31.0 ms

Now, you can use the same ssh command to ssh into your vultr serverusing your domain name.

ssh username@domain.com

Setting up hugo on your local PC

Hugo is a popular open-source static site generator. It allows you to take markdown files, and builds them into and html website. To start go to https://gohugo.io/installation/ and download Hugo on your local computer. (I will show you how to upload the site to your server later.)

Pick a theme The theme I use is here https://themes.gohugo.io/themes/hugo-theme-hello-friend-ng/

You can browse your own themes as well. Just make sure to follow the installation instructions. Let’s create a new Hugo site. Change into the directory where you want your site to be located in. Mine rests in ~/Documents/.

cd ~/Documents/

Create your new Hugo site.

hugo new site site-name

This will make a new folder with your site name in the ~/Documents directory. This folder will have a few directories and a config file in it.

archetypes  config.toml  content  data  layouts  public  resources  static  themes

For this tutorial, we will be working with the config.toml file and the content, public, static, and themes. Next, load the theme into your site directory. For the Hello Friend NG theme:

git clone https://github.com/rhazdon/hugo-theme-hello-friend-ng.git themes/hello-friend-ng

Now we will load the example site into our working site. Say yes to overwrite.

cp -a themes/hello-friend-ng/exampleSite/* .

The top of your new config.toml site now contains:

baseURL = "https://example.com"
title   = "Hello Friend NG"
languageCode = "en-us"
theme = "hello-friend-ng"

Replace your baseURL with your site name and give your site a title. Set the enableGlobalLanguageMenu option to false if you want to remove the language swithcer option at the top. I also set enableThemeToggle to true so users could set the theme to dark or light.

You can also fill in the links to your social handles. Comment out any lines you don’t want with a “#” like so:

[params.social](params.social)
    name = "twitter"
    url  = "https://twitter.com/"

  [params.social](params.social)
    name = "email"
    url  = "mailto:nobody@example.com"

  [params.social](params.social)
    name = "github"
    url  = "https://github.com/"

  [params.social](params.social)
    name = "linkedin"
    url  = "https://www.linkedin.com/"

 # [params.social](params.social)
   # name = "stackoverflow"
   # url  = "https://www.stackoverflow.com/"

You may also want to edit the footer text to your liking. I commented out the second line that comes with the example site:

[params.footer]
    trademark = true
    rss = true
    copyright = true
    author = true

    topText = []
    bottomText = [
     # "Powered by <a href=\"http://gohugo.io\">Hugo</a>",
     #  "Made with &#10084; by <a href=\"https://github.com/rhazdon\">Djordje Atlialp</a>"
    ]

Now, move the contents of the example contents folder over to your site’s contents folder (giggidy):

cp -r ~/Documents/hugo/themes/hello-friend-ng/exampleSite/content/* ~/Documents/hugo/content/

Let’s clean up a little bit. Cd into ~/Documents/hugo/content/posts. Rename the file to the name of your first post. Also, delete all of the other files here:

cd ~/Documents/hugo/contents/posts
mv goisforlovers.md newpostnamehere.md
find . ! -name 'newpostnamehere.md' -type f -exec rm -f {} +

Open the new post file and delete everything after this:

+++
title = "Building a Minimalist Website with Hugo"
description = ""
type = ["posts","post"]
tags = [
    "hugo",
    "nginx",
    "ssl",
    "http",
    "vultr",
]
date = "2023-03-26"
categories = [
    "tools",
    "linux",
]
series = ["tools"]
[ author ]
  name = "David Thomas"
+++

You will need to fill out this header information for each new post you make. This will allow you to give your site a title, tags, date, categories, etc. This is what is called a TOML header. TOML stands for Tom’s Obvious Minimal Language. Which is a minimal language used for parsing data. Hugo uses TOML to fill out your site.

Save your doc and exit. Next, there should be an about.md page now in your ~/Documents/hugo/Contents folder. Edit this to edit your about page for your site. You can use this Markdown Guide if you need help learning markdown language. https://www.markdownguide.org/

Serve your website locally

Let’s test the website by serving it locally and accessing it at localhost:1313 in your web browser. Enter the command:

hugo serve

Hugo will now be generating your website. You can view it by entering localhost:1313 in your webbrowser.

You can use this to test new changes before uploading them to your server. When you svae a post or page file such as your about page, hugo will automatically update the changes to this local page if the local server is running.

Press “Ctrl + c” to stop this local server. This is only for testing and does not need to be running to make your site work.

Build out your public directory

Okay, your website is working locally, how do we get it to your server to host it online? We are almost there. First, we will use the hugo command to build your website in the public folder. Then, we will make a copy of our public folder on our server using rsync. I will also show you how to create an alias so you do not have to remember the rsync command every time.

From your hugo site folder run:

hugo

Next, we will put your public hugo folder into /var/www/ on your server. Here is how to do that with an alias. Open ~/.bashrc.

vim ~/.bashrc

Add the following line to the end of the file, making sure to replace the username and server name:

# My custom aliases
alias rsyncp='rsync -rtvzP ~/Documents/hugo/public/ username@myserver.com:/var/www/public'

Save and exit the file. Then tell bash to update it’s source config file.

source ~/.bashrc

Now your can run the command by just using the new alias any time. Your will need to do this every time you update your site locally.

rsyncp

Set up nginx on your server

Install nginx

apt update
apt upgrade
apt install nginx

create an nginx config file in /etc/nginx/sites-available/

vim /etc/nginx/sites-available/public

You will need to add the following to the file, update the options, then save and exit:

server {
        listen 80 ;
        listen [::]:80 ;
        server_name example.org ;
        root /var/www/mysite ;
        index index.html index.htm index.nginx-debian.html ;
        location / {
                try_files $uri $uri/ =404 ;
        }
}

Enter your domain in “server_name” line in place of “example.org”. Also, point “root” to your new site file from earlier. (/var/www/public). Then save and exit.

Link this site-available config file to sites-enabled to enable it. Then restart nginx:

ln -s /etc/nginx/sites-available/public /etc/nginx/sites-enabled
systemctl reload nginx

Access Permissions

We will need to make sure nginx has permissions to your site folder so that it can access them to serve your site. Run:

chmod 777 /var/www/public

Firewall Permissions

You will need to make sure your firewall allows port 80 and 443. Vultr installs the ufw program by default. But your can install it if you used a different provider. Beware, enabling a firewalll could block you from accessing your vm, so do your research before tinkering outside of these instructions.

ufw allow 80
ufw allow 443

Nginx Security

We will want to hide your nginx version number on error pages. This will make your site a bit harder for hackers to find exploits. Open your Nginx config file at /etc/nginx/nginx.conf and remove the “#” before “server_tokens off;”

Enter your domain into your browser. Congrats! You now have a running website!

Use Certbot to enable HTTPS

Right now, our site uses the unencrypted http. We want it to use the encrypted version HTTPS (HTTP over SSL). This will increase user privacy, hide usernames and passwords used on your site, and you get the lock symbol by your URL name instead of “!not secure”.

Install Certbot and It’s Nginx Module

apt install python3-certbot-nginx

Run certbot

certbot --nginx

Fill out the information, certbot asks for your emaill so it can send you a reminder when the certs need to be renewed every 3 months. You do not need to consent to giving your email to the EFF. Press 1 to select your domain. And 2 too redirect all connections to HTTPS.

Certbot will build out some information in your site’s config file. Refresh your site. You should see your new fancy lock icon.

Set Up a Cronjob to automatically Renew certbot certs

crontab -e

Select a text editor and add this line to the end of the file. Then save and exit the file:

0 0 1 * * certbot --nginx renew

You now have a running website. Just make new posts locally, the run “hugo” to rebuild the site. And use the rsync alias to update the folder on your server. I will soon be making tutorials on making an email address for your domain, such as david@perfectdarkmode.com on my site. I will also be adding a comments section, RSS feed, email subscription, sidebar, and more.

Feel free to reach out with any questions if you get stuck. This is meant to be an all encompassing guide. So I want it to work.

Extras

Optimizing images

Create assets folder in main directory.

Create images folder in /assets

Access image using hugo pipes

{{ $image := resources.Get "images/test-image.jpg" }}
<img src="{{ ( $image.Resize "500x" ).RelPermalink }}" />

https://gohugo.io/content-management/image-processing/

How to Process Bookfusion Highlights with Vim

Here are my highlights pulled up in Vim:

As you can see, Bookfusion gives you a lot of extra information when you export highlights. First, let’s get rid of the lines that begin with ##

Enter command mode in Vim by pressing esc. Then type :g/^##/d and press enter.

Much better.

Now let’s get rid of the color references:`

:g/^Color/d

To get rid of the timestamps, we must find a different commonality between the lines. In this case, each line ends with “UTC”. Let’s match that:

:g/UTC$/d

Where $ matches the end of the line.

Now, I want to get rid of the > on each line: %s/> //g

Almost there, you’ll notice there are 6 empty lines in between each highlight. Let’s shrink those down into one:

:%s/\(\n\)\{3,}/\r\r/g

The command above matches newline character n 3 or more times and replaces them with two newline characters /r/r.

As we scroll down, I see a few weird artifacts from the book conversion to markdown.

Now, I want to get rid of any carrot brackets in the file. Let’s use the substitute command again here:

%s/<//g

Depending on your book and formatting. You may have some other stuff to edit.

How to Set Up Hugo Relearn Theme

Hugo Setup

Adding a module as a theme

Make sure Go is installed

go version

Create a new site

hugo new site sitename
cd sitename

Initialize your site as a module

hugo mod init sitename

Confirm

cat go.mod

Add the module as a dependency using it’s git link

hugo mod get github.com/McShelby/hugo-theme-relearn

Confirm

cat go.mod

add the theme to config.toml

# add this line to config.toml and save
theme = ["github.com/McShelby/hugo-theme-relearn"]

Confirm by viewing site

hugo serve
# visit browser at http://localhost:1313/ to view site

Adding a new “chapter” page

hugo new --kind chapter Chapter/_index.md

Add a home page

hugo new --kind home _index.md

Add a default page

hugo new <chapter>/<name>/_index.md

hugo new <chapter>/<name>.md

You will need to change some options in _index.md

+++
# is this a "chaper"?
chapter=true
archetype = "chapter"
# page title name
title = "Linux"
# The "chapter" number
weight = 1
+++

Adding a “content page” under a category

hugo new basics/first-content.md

Create a sub directory:

hugo new basics/second-content/_index.md

change draft = true to draft = false in the content page to make a page render.

Global site parameters

Add these to your config.toml file and edit as you please

[params]
  # This controls whether submenus will be expanded (true), or collapsed (false) in the
  # menu; if no setting is given, the first menu level is set to false, all others to true;
  # this can be overridden in the pages frontmatter
  alwaysopen = true
  # Prefix URL to edit current page. Will display an "Edit" button on top right hand corner of every page.
  # Useful to give opportunity to people to create merge request for your doc.
  # See the config.toml file from this documentation site to have an example.
  editURL = ""
  # Author of the site, will be used in meta information
  author = ""
  # Description of the site, will be used in meta information
  description = ""
  # Shows a checkmark for visited pages on the menu
  showVisitedLinks = false
  # Disable search function. It will hide search bar
  disableSearch = false
  # Disable search in hidden pages, otherwise they will be shown in search box
  disableSearchHiddenPages = false
  # Disables hidden pages from showing up in the sitemap and on Google (et all), otherwise they may be indexed by search engines
  disableSeoHiddenPages = false
  # Disables hidden pages from showing up on the tags page although the tag term will be displayed even if all pages are hidden
  disableTagHiddenPages = false
  # Javascript and CSS cache are automatically busted when new version of site is generated.
  # Set this to true to disable this behavior (some proxies don't handle well this optimization)
  disableAssetsBusting = false
  # Set this to true if you want to disable generation for generator version meta tags of hugo and the theme;
  # don't forget to also set Hugo's disableHugoGeneratorInject=true, otherwise it will generate a meta tag into your home page
  disableGeneratorVersion = false
  # Set this to true to disable copy-to-clipboard button for inline code.
  disableInlineCopyToClipBoard = false
  # A title for shortcuts in menu is set by default. Set this to true to disable it.
  disableShortcutsTitle = false
  # If set to false, a Home button will appear below the search bar on the menu.
  # It is redirecting to the landing page of the current language if specified. (Default is "/")
  disableLandingPageButton = true
  # When using mulitlingual website, disable the switch language button.
  disableLanguageSwitchingButton = false
  # Hide breadcrumbs in the header and only show the current page title
  disableBreadcrumb = true
  # If set to true, hide table of contents menu in the header of all pages
  disableToc = false
  # If set to false, load the MathJax module on every page regardless if a MathJax shortcode is present
  disableMathJax = false
  # Specifies the remote location of the MathJax js
  customMathJaxURL = "https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"
  # Initialization parameter for MathJax, see MathJax documentation
  mathJaxInitialize = "{}"
  # If set to false, load the Mermaid module on every page regardless if a Mermaid shortcode or Mermaid codefence is present
  disableMermaid = false
  # Specifies the remote location of the Mermaid js
  customMermaidURL = "https://unpkg.com/mermaid/dist/mermaid.min.js"
  # Initialization parameter for Mermaid, see Mermaid documentation
  mermaidInitialize = "{ \"theme\": \"default\" }"
  # If set to false, load the Swagger module on every page regardless if a Swagger shortcode is present
  disableSwagger = false
  # Specifies the remote location of the RapiDoc js
  customSwaggerURL = "https://unpkg.com/rapidoc/dist/rapidoc-min.js"
  # Initialization parameter for Swagger, see RapiDoc documentation
  swaggerInitialize = "{ \"theme\": \"light\" }"
  # Hide Next and Previous page buttons normally displayed full height beside content
  disableNextPrev = true
  # Order sections in menu by "weight" or "title". Default to "weight";
  # this can be overridden in the pages frontmatter
  ordersectionsby = "weight"
  # Change default color scheme with a variant one. Eg. can be "auto", "red", "blue", "green" or an array like [ "blue", "green" ].
  themeVariant = "auto"
  # Change the title separator. Default to "::".
  titleSeparator = "-"
  # If set to true, the menu in the sidebar will be displayed in a collapsible tree view. Although the functionality works with old browsers (IE11), the display of the expander icons is limited to modern browsers
  collapsibleMenu = false
  # If a single page can contain content in multiple languages, add those here
  additionalContentLanguage = [ "en" ]
  # If set to true, no index.html will be appended to prettyURLs; this will cause pages not
  # to be servable from the file system
  disableExplicitIndexURLs = false
  # For external links you can define how they are opened in your browser; this setting will only be applied to the content area but not the shortcut menu
  externalLinkTarget = "_blank"

Syntax highlighting

Supports a variety of [Code Syntaxes] To select the syntax, wrap the code in backticks and place the syntax by the first set of backticks.

```bash
echo hello
\```

Adding tags

Tags are displayed in order at the top of the page. They will also display using the menu shortcut made further down.

Add tags to a page:

+++
tags = ["tutorial", "theme"]
title = "Theme tutorial"
weight = 15
+++

Choose a default color theme

Add to config.toml with the chosen theme for the “style” option:

[markup]
  [markup.highlight]
    # if `guessSyntax = true`, there will be no unstyled code even if no language
    # was given BUT Mermaid and Math codefences will not work anymore! So this is a
    # mandatory setting for your site if you want to use Mermaid or Math codefences
    guessSyntax = false

    # choose a color theme or create your own
    style = "base16-snazzy"

Add Print option and search output page.

add the following to config.toml

[outputs]
  home = ["HTML", "RSS", "PRINT", "SEARCH"]
  section = ["HTML", "RSS", "PRINT"]
  page = ["HTML", "RSS", "PRINT"]

Customization

This theme has a bunch of editable customizations called partials. You can overwrite the default partials by putting new ones in /layouts/partials/.

to customize “partials”, create a “partials” directory under site/layouts/

cd layouts
mkdir partials
cd partials

You can find all of the partials available for this theme here

Change the site logo using the logo.html partial

Create logo.html in /layouts/partials

vim logo.html

Add the content you want in html. This can be an img html tag referencing an image in the static folder. Or even basic text. Here is the basic syntax of an html page, adding “Perfect Dark Mode” as the text to display:

<!DOCTYPE html>
<html>
<body>

<h3>Perfect Dark Mode</h3>

</body>
</html>

Add a favicon to your site

This is pasted from the relearn site. Add Favicon and edit * If your favicon is a SVG, PNG or ICO, just drop off your image in your local static/images/ folder and name it favicon.svg, favicon.png or favicon.ico respectively.

If no favicon file is found, the theme will lookup the alternative filename logo in the same location and will repeat the search for the list of supported file types.

If you need to change this default behavior, create a new file in layouts/partials/ named favicon.html. Then write something like this:

<link rel="icon" href="/images/favicon.bmp" type="image/bmp">

Changing theme colors

In your config.toml file edit the themeVariant option under [params]

  themeVariant = "relearn-dark"

There are some options to choose from or you can custom make your theme colors by using this stylesheet generator

Menu Shortcuts Add a [[menu.shortcuts]] entry for each link

[[menu.shortcuts]]
name = "<i class='fab fa-fw fa-github'></i> GitHub repo"
identifier = "ds"
url = "https://github.com/McShelby/hugo-theme-relearn"
weight = 10

[[menu.shortcuts]]
name = "<i class='fas fa-fw fa-camera'></i> Showcases"
url = "more/showcase/"
weight = 11

[[menu.shortcuts]]
name = "<i class='fas fa-fw fa-bookmark'></i> Hugo Documentation"
identifier = "hugodoc"
url = "https://gohugo.io/"
weight = 20

[[menu.shortcuts]]
name = "<i class='fas fa-fw fa-bullhorn'></i> Credits"
url = "more/credits/"
weight = 30

[[menu.shortcuts]]
name = "<i class='fas fa-fw fa-tags'></i> Tags"
url = "tags/"
weight = 40

Extras

Menu button arrows. (Add to page frontmatter)

menuPre = "<i class='fa-fw fas fa-caret-right'></i> "

You Need to Learn Man Pages

https://www.youtube.com/watch?v=RzAkjX_9B7E&t=295s

Man (manual) pages are the built in help system for Linux. They contain documentation for most commands.

Run the man command on a command to get to it’s man page. man man

Navigating a man page h

Get help

q

Quit out of the man page

Man uses less

^ mean ctrl

^f Forward one page

^b backward one page

can use # followed by command to repeat that many times

g first line in file

G last line in file

CR means press enter

Searching

/searchword

press enter to jump first occurance of searched word

n to jump to next match

N to go to previous match

?searchword to do a backward search (n and N are reversed when going through results)

Man page conventions

bold text type as shown

italic text replace with arguments

Italic may not render in terminal and may be underlined or colored text instead.

[-abc] optional

-a | -b Options separated by a pipe symbol cannot be used together.

argument … (followed by 3 dots) can be repeated. (Argument is repeatable)

[expression] … entire expression within [ ] is repeatable.

Parts of a man page

Name

name of command

Synopsis

How to use the command

When you see file in a man page, think file and or directory

Description short and long options do the same thing

Current section number is printed at the top left of the man page.

-k to search sections using apropos

[root@server30 ~]# man -k unlink
mq_unlink (2)        - remove a message queue
mq_unlink (3)        - remove a message queue
mq_unlink (3p)       - remove a message queue (REALT...
sem_unlink (3)       - remove a named semaphore
sem_unlink (3p)      - remove a named semaphore
shm_open (3)         - create/open or unlink POSIX s...
shm_unlink (3)       - create/open or unlink POSIX s...
shm_unlink (3p)      - remove a shared memory object...
unlink (1)           - call the unlink function to r...
unlink (1p)          - call theunlink() function
unlink (2)           - delete a name and possibly th...
unlink (3p)          - remove a directory entry
unlinkat (2)         - delete a name and possibly th...]

Shows page number in ()

The sections that end in p are POSIX documentation. Theese are not specific to Linux.

[root@server30 ~]# man -k "man pages"
lexgrog (1)          - parse header information in man pages
man (7)              - macros to format man pages
man-pages (7)        - conventions for writing Linux man pages
man.man-pages (7)    - macros to format man pages
[root@server30 ~]# man man-pages

Use man-pages to learn more about man pages

Sections within a manual page
       The list below shows conventional or suggested sections.  Most manual
       pages should include at least the highlighted  sections.   Arrange  a
       new manual page so that sections are placed in the order shown in the
       list.

              NAME
              LIBRARY          [Normally only in Sections 2, 3]
              SYNOPSIS
              CONFIGURATION    [Normally only in Section 4]
              DESCRIPTION
              OPTIONS          [Normally only in Sections 1, 8]
              EXIT STATUS      [Normally only in Sections 1, 8]
              RETURN VALUE     [Normally only in Sections 2, 3]
              ERRORS           [Typically only in Sections 2, 3]
              ENVIRONMENT
              FILES
              ATTRIBUTES       [Normally only in Sections 2, 3]
              VERSIONS         [Normally only in Sections 2, 3]
              STANDARDS
              HISTORY
              NOTES
              CAVEATS
              BUGS
              EXAMPLES
              AUTHORS          [Discouraged]
              REPORTING BUGS   [Not used in man-pages]
              COPYRIGHT        [Not used in man-pages]
              SEE ALSO

Shell builtins do not have man pages. Look at the shell man page for info on them. man bash

Search for the Shell Builtins section: /SHELL BUILTIN COMMANDS

You can find help on builtins with the help command:

david@fedora:~$ help hash
hash: hash [-lr] [-p pathname] [-dt] [name ...]
    Remember or display program locations.
    
    Determine and remember the full pathname of each command NAME.  If
    no arguments are given, information about remembered commands is displayed.
    
    Options:
      -d	forget the remembered location of each NAME
      -l	display in a format that may be reused as input
      -p pathname	use PATHNAME as the full pathname of NAME
      -r	forget all remembered locations
      -t	print the remembered location of each NAME, preceding
    		each location with the corresponding NAME if multiple
    		NAMEs are given
    Arguments:
      NAME	Each NAME is searched for in $PATH and added to the list
    		of remembered commands.
    
    Exit Status:
    Returns success unless NAME is not found or an invalid option is given.

help without any arguments displays commands you can get help on.

david@fedora:~/Documents/davidvargas/davidvargasxyz.github.io$ help help
help: help [-dms] [pattern ...]
    Display information about builtin commands.
    
    Displays brief summaries of builtin commands.  If PATTERN is
    specified, gives detailed help on all commands matching PATTERN,
    otherwise the list of help topics is printed.
    
    Options:
      -d	output short description for each topic
      -m	display usage in pseudo-manpage format
      -s	output only a short usage synopsis for each topic matching
    		PATTERN
    
    Arguments:
      PATTERN	Pattern specifying a help topic
    
    Exit Status:
    Returns success unless PATTERN is not found or an invalid option is given.

type command tells you what type of command something is.

Using man on some shell builtins brings you to the bash man page Shell Builtin Section

Many commands support -h or --help options to get quick info on a command.

Tools

Posts

Calibre Web with Docker and NGINX

How to Build a website With Hugo

How to Process Bookfusion Highlights with Vim

How to Set Up Hugo Relearn Theme

You Need to Learn Man Pages

Subsections of Tools

Calibre Web with Docker and NGINX

Install Docker

Configure Nginx to act as a reverse proxy for Calibre Web

DNS CNAME Record

SSL Certificate

Site Setup

Adding new books

How to Build a website With Hugo

Setting up a Virtual Private Server (VPS)

Registering a Domain Name

Setting up hugo on your local PC

Serve your website locally

Build out your public directory

Set up nginx on your server

Access Permissions

Firewall Permissions

Nginx Security

Use Certbot to enable HTTPS

Install Certbot and It’s Nginx Module

Run certbot

Set Up a Cronjob to automatically Renew certbot certs

Extras

Optimizing images

How to Process Bookfusion Highlights with Vim

How to Set Up Hugo Relearn Theme

Hugo Setup

Adding a module as a theme

Global site parameters

Syntax highlighting

Adding tags

Choose a default color theme

Add Print option and search output page.

Customization

Change the site logo using the logo.html partial

Add a favicon to your site

Changing theme colors

You Need to Learn Man Pages

Searching

Man page conventions

Parts of a man page