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Announcements of releases and security updates

Version lifecycle

Version lifecycle

Cheatsheet, book


How to Get the Old Wikipedia Layout Back

Keyboard shortcut

  • Save: Alt+s (non-mac), Ctr+Option+s (Mac)
  • Preview: Alt+p (non-mac), Ctrl+Option+p (Mac)

Install mediawiki on ubuntu

Check requirement

php -v
mysql -V  # capital V

http://localhost/mediawiki setup

  • Language
  • Welcome to MediaWiki!
    • Environmental checks
    • Copyright and Terms
  • Connect to database - MySQL settings
    • Database host: localhost
    • Database name: (default is my_wiki)
    • Database table prefix: (Leave it empty)
    • Database username: root (saved in LocalSettings.php - $wgDBuser, no need to change)
    • Database password: (saved in LocalSettings.php - $wgDBpassword)
  • Database settings
    • Storage engine: InnoDB
    • Database character set: Binary
  • Name
    • Name of wiki: (saved in LocalSettings.php - $wgSitename)
    • Administrator account
      • Your username: (will be saved in the database)
      • Password: (will be saved in the database)
      • Email address: (leave it empty)
      • Uncheck 'Share data about this installation with MediaWiki developers.'
      • Check 'I'm bored already, just install the wiki.'

If we choose 'Ask me more questions', we will get more questions to answer

  • Options
    • User rights profile: Open wiki/Account creation required/Authorized editors only/Private wiki
    • Copyright and license: Creative Commons Attribution/.../No license footer/Select a custom Creative Commons license
    • Email settings
    • Skins
    • Extensions: Gadgets, ImageMap, InputBox, Interwiki, LocalisationUpdate, Nuke, ParserFunctions, PdfHandler, Renameuser, SpamBlacklist, SyntaxHighlight_GeSHi, TitleBlacklist, WikiEditor
    • Images and file uploads: Enable file uploads, Logo URL
    • Advanced configuration: PHP object caching (APC, APCu, XCache or WinCache)

At the end, we will be notified to download LocalSettings.php file. The new database will be created now.

$ mysql -u root -p -e 'SHOW DATABASES'

$ mysql -u root -p -e 'SHOW TABLES' DB_NAME

Enable tex for formula

1. The following line is coming from an earlier bookmarked tutorial (this will install texvc & mediawiki together)

apt-get install mediawiki-math

2. Download Math extension from this link

3. Then you should extract the archive in the "extensions" folder within your MediaWiki installation directory.

4. Next, you need to add the following line to your LocalSettings.php file:

wfLoadExtension( 'Math' );

5. Install texvc and ocaml (outdated). Installing texvc seems not necessary now according to this post.

sudo apt-get install ocaml
cd extensions/Math/math

6. The next step is to execute the "maintenance/update.php" script via shell:

php maintenance/update.php  

Done. Go to test it. [Tested on mediawiki 1.22 on Ubuntu 12.04]. Navigate to "Special:Version" on your wiki to verify that the extension is successfully installed.


The default skin is vector.


cd Downloads
tar xzvf MobileFrontend-REL1_30-5ecc673.tar.gz -C ../mediawiki-1.30.0/extensions/
tar xzvf MinervaNeue-REL1_30-7ee8663.tar.gz -C ../mediawiki-1.30.0/skins
  • Use a table or phone to test the effect. It works. The changes I made to <LocalSettings.php>
wfLoadSkin( 'MinervaNeue' ); # put it in the same section of wfLoadSkin

wfLoadExtension( 'MobileFrontend' );
$wgMFAutodetectMobileView = true;
$wgMFDefaultSkinClass = 'SkinMinerva';

$wgShowExceptionDetails = true; # debugging use only

Change default port

How can I change mediawiki's port? MediaWiki runs under httpd, so either change httpd's port, or listen on another port as well and create a virtual host on this new port for running MediaWiki.

Composer and PHP

What Is Composer for PHP and How to Install It

Install on Ubuntu 16.04, 18.04, 20.04, 22.04

Install mediawiki on debian

  • Cons: 1) Filesystem is too complicated, 2) MySql/mariadb is not included?
    $ sudo apt install mediawiki
    The following additional packages will be installed:
      apache2 apache2-bin apache2-data apache2-utils libapache2-mod-php8.2 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap liblua5.3-0
      libsodium23 libxslt1.1 mediawiki-classes php php-common php-intl php-mbstring php-mysql php-xml php8.2 php8.2-cli php8.2-common php8.2-intl
      php8.2-mbstring php8.2-mysql php8.2-opcache php8.2-readline php8.2-xml
    $ sudo apt remove mediawiki
    The following packages were automatically installed and are no longer required:
      apache2 apache2-bin apache2-data apache2-utils libapache2-mod-php8.2 libapr1 libaprutil1 libaprutil1-dbd-sqlite3 libaprutil1-ldap liblua5.3-0
      libsodium23 libxslt1.1 mediawiki-classes php php-common php-intl php-mbstring php-mysql php-xml php8.2 php8.2-cli php8.2-common php8.2-intl
      php8.2-mbstring php8.2-mysql php8.2-opcache php8.2-readline php8.2-xml
    Use 'sudo apt autoremove' to remove them.
    The following packages will be REMOVED:
  • Manual:Running MediaWiki on Debian or Ubuntu

Install mediawiki through Vagrant + VirtualBox

Several extensions have an instruction for vagrant engine.

vagrant roles enable mobilefrontend --provision
vagrant enable-role multimediaviewer 
vagrant provision

Run mediawiki with Docker

Install mediawiki on XAMPP


  • $wgSitename = "BRB-ArrayTools";

The protocol and server name to use in fully-qualified URLs

  • $wgServer = "https://YOURDOMAIN.COM";
  • $wgSecureLogin = true;
  • $wgLogo = "$wgScriptPath/YOURLOGO.png";
  • $wgEnableEmail = false;

The base URL path

Database settings

  • $wgDBtype = "mysql";
  • $wgDBserver = "localhost";
  • $wgDBname = "MYWIKIDB";
  • $wgDBuser = "root"; # not the wiki user
  • $wgDBpassword = "MYPASSWORD"; # not the password used to log in the mediawiki

Shared memory settings

  • $wgMainCacheType = CACHE_ACCEL;

To enable image uploads, make sure the 'images' directory is writable, then set this to true:

  • $wgEnableUploads = true;

If you use ImageMagick (or any other shell command) on a Linux server, this will need to be set to the name of an available UTF-8 locale

  • $wgShellLocale = "en_US.utf8";


  • wfLoadExtension( 'SyntaxHighlight_GeSHi' );
  • $wgFileExtensions = array('txt','svg','png','gif','jpg','jpeg','doc','xls','mpp','pdf','ppt','tiff','bmp','docx', 'xlsx', 'pptx','ps','odt','ods','odp','odg');
  • $wgSVGConverter = 'ImageMagick';
  • $wgTrustedMediaFormats = array('text/plain');
  • $wgDisableCounters = true;
  • $wgLocaltimezone = "America/New_York";
  • $wgLocalTZoffset = date("Z") / 60;
  • date_default_timezone_set( $wgLocaltimezone );
  • require_once("$IP/extensions/Math/Math.php");
  • $wgFavicon = "$wgScriptPath/favicon32.ico";


Customize MediaWiki into Your Ultimate Collaborative Web Site

Prevent access

Special pages

Uninstall mediawiki

  1. delete the directory containing the wiki's files
  2. remove the MySQL database holding your wiki
mysql> DROP DATABASE wikidb;

Mediawiki database


See the internal MySQL link.

  • It seems not necessary to create a new user for storing the mediawiki database; root is OK
  • The mediawiki database administrator information will not be saved to the database
  • The mediawiki user account will be written to the database.


A list of users including the system administrator can be found under Special pages > User list (No log in is required).

The administrator and users information is saved in the 'user' table of the wiki database. The can be seen by looking at the phpMyAdmin page. LocalSettings.php only saved the database name and username/password in order to get an access.

To reset user's password, follow official wikipedia page

# set the password for username 'example' to 'newpassword'
sudo php changePassword.php --user=example --password=newpassword


Comment symbol in LocalSettings.php

Use the pound sign '#', not double forward slashes '//'.

Preformatted text with text wrap

Search 'Customized preformatted' on the Formatting page.

<pre style="white-space: pre-wrap; /* CSS 3 */ white-space: -moz-pre-wrap; /* Mozilla, since 1999 */ white-space: -pre-wrap; /* Opera 4-6 */ white-space: -o-pre-wrap; /* Opera 7 */ word-wrap: break-word; /* IE 5.5+ */ " > YOUR TEXT </pre>

Color format: CSS

Text is red.

<span style="color: red">
Text is red.

Another example: Template::Mvar.

Preformatted text: nowiki

If we want to escape from wikipedia's interpretation & avoiding using pre which will create a block, we can use nowiki. One example is {{mvar}} instead of {{{1}}}.

"span" tag for fixed width text with colored background

The code tag is supposed to give a background color for a fixed width text but it spreads a whole line for some reason. code

An alternative but not exactly same way is to use the span tag from HTML; see an example where a border is added around the text.

This text background color is specified.

This text will be yellow and on a green background

Display special characters like backslash using unicode

Formatting: Superscript and subscript



or sub keyword.

Syntax highlight

Warnings: syntax highlight will use much CPU. It will affect mediawiki's performance ('top' command will show that). Even on Rasp Pi3B+, it is slow. So don't use this feature.

Use the "syntaxhighlight" (for newer versions of mediawiki) or source (for older versions) tag for inline/non-inline syntax highlight. For example,


Source <- c("A", "A", "A", "A", "B", "B", "C", "C", "D") 
Target <- c("B", "C", "D", "J", "E", "F", "G", "H", "I") 
NetworkData <- data.frame(Source, Target) 

d3SimpleNetwork(NetworkData, height = 800, width = 1024, file="tmp.html")

can be created by

<source lang="rsplus">

Source <- c("A", "A", "A", "A", "B", "B", "C", "C", "D") 
Target <- c("B", "C", "D", "J", "E", "F", "G", "H", "I") 
NetworkData <- data.frame(Source, Target) 

d3SimpleNetwork(NetworkData, height = 800, width = 1024, file="tmp.html")

Note for some reason, when I use the syntaxhighlight tag (use syntaxhighlight instead of source tag), 'r' is not recognized on my mediawiki 1.22 although 'bash' works.

This syntax highlight extension package seems more complete. It supports markdown, cpp, r, bash, cxx, ... (no Fortran?) languages. But highlight.js library supports even more.

If we need to use code syntaxhighlight with a list, we shall put the beginning "syntaxhighlight" tag immediately after the paragraph instead of a new line. Putting the tag immediately after the paragraph allows an indentation of the code.

It seems the inline parameter does not work. Right now, I can use this way mtcars |> lm(mpg ~ disp, data = _) |> _$coef.

Create tables

Introduction Introduction Installation Installation Packages and Repositories Packages and
File Managers File Managers
Desktop Add-ons Desktop Add-ons Virtual Machines Virtual Machines Games and Entertainment Games and
Internet Internet

Indent a table or math equation in a list

Use single, double, triple colons. See a discussion and my example here.

Note that if the table is inside a second bullets (**), the bullet level will be reset.

Color of a cell in a table


Indent in a numbered list

Search "colon" in

  1. one
    some stuff
    some more stuff
  2. two

OR using HTML syntax <ol>/<ul> and <li>

  1. one
  2. two
  3. some stuff
    some more stuff
  4. three

Indent pre or a block of code

  • Still indent for the next item in a list

How can I link to a specific answer?

Mediawiki/Apache has no response

sudo /etc/init.d/apache2 restart

Auto timeout



On ubuntu, change /etc/php5/apache2/php.ini.


session.gc_maxlifetime = 1440

session.cookie_lifetime = 1440

After modifying php.ini, you need to restart apache. sudo /etc/init.d/apache2 restart

'keep me logged in' option

Make sure to check this option on the login screen.

Errors and symptoms

Sorry! We could not process your edit due to a loss of session data. You might have been logged out. Please verify that you're still logged in and try May be related to Cookies. See also Discussion.

Class "FormatJson" not found

See this. I have added the empty line at the end of FormatJson.php. And the installation seems running.


Move favicon.ico to the mediawiki folder and include the following line in the <LocalSettings.php>

$wgFavicon = "$wgScriptPath/favicon.ico";

Note that the attribute of the ico file has to be at least 644. If not, just run the following line

chmod 644 favicon.ico

To download a favicon, use the approach here. For example, to download the favicon icon from website, we just open the url

The approach works is based on the assumption that the favicon.ico file name is not changed and usually located under the website root directory.


It works 👍 when I copy and paste emoji from

Change skin

Change user's password

cd maintenance
sudo php changePassword.php --user=UserName --password=NewPassword

tackle slowness when saving pages

In summary:

1. Install php-apc. sudo apt-get install php-apc

2. nano LocalSettings.php. Change $wgMainCacheType from CACHE_NONE to CACHE_ACCEL.

$wgMainCacheType = CACHE_ACCEL;

3. (optional) sudo /etc/init.d/apache2 reload

Apache vs Nginx

The URL can be different when I use Apache or Nginx. It is related to CGI support; see Manual:Short URL/it.

See Guide for the Apache/Nginx configuration and LocalSettings.php.

Nginx and PHP

Browser's tools

  • Chrome: Ctrl+Shift + i. Click the 'Network' tab. See the page size, loading time, ...

Alternatives to mediawiki

How to Create a Wiki: The 7 Best Sites That Make It Easy

3 Alternatives To MediaWiki When Hosting Your Own Wiki

15 best alternative to MediaWiki?


Install moinmoin

Article size and its limit

To view what the size of the current (and other revisions) of the page is, open the page on the frontend and view its history.

How to change the maximum allowed page size in MediaWiki

By default the size is 2048 KB. You can modify it in LocalSettings.php.

$wgMaxArticleSize = 100;  # 100 KB

Shorten URL (remove index.php)

  • Apache guide. Keywords: RewriteRule & index.php
    • Configuring Short URLs in MediaWiki. It provides two ways to shorten the URL. One is to use alias and the other is Rewriting.
    • How To Install MediaWiki on Ubuntu 18.04 LTS. Follow Steps 7 & 8.
      # Enabling mod_rewrite
      sudo a2enmod rewrite
      sudo systemctl restart apache2
      # Setting Up Apache2 configuration file
      sudo nano /etc/apache2/sites-available/mediawiki.conf  # new file
      sudo a2ensite mediawiki.conf
      sudo a2dissite 000-default.conf
      sudo apache2ctl configtest
      sudo systemctl restart apache2
      # Setting up the rewrite rules
      sudo nano /var/www/html/.htaccess  # new file
      # LocalSettings.php
      sudo mv /var/www/html/mediawiki /var/www/html/w
      sudo nano /var/www/html/w/LocalSettings.php
      # $wgScriptPath = "/w";
      # $wgArticlePath = "/wiki/$1";
      # $wgUsePathInfo = true;

      where /etc/apache2/sites-available/mediawiki.conf is

      <VirtualHost *:80>
          <Directory /var/www/html>
              Options Indexes FollowSymLinks MultiViews
              AllowOverride All
              Require all granted
          ServerAdmin webmaster@localhost
          DocumentRoot /var/www/html
          ErrorLog ${APACHE_LOG_DIR}/error.log
          CustomLog ${APACHE_LOG_DIR}/access.log combined

      and /var/www/html/.htaccess is

      # Enable the rewrite engine
      RewriteEngine On
      # Short URL for wiki pages
      # http://domain/w/index.php/Main_Page becomes http://domain/wiki/Main_Page
      RewriteRule ^/?wiki(/.*)?$ %{DOCUMENT_ROOT}/w/index.php [L]
      # Redirect / to Main Page
      # http://domain will go to http://domain/wiki/Main_Page
      RewriteRule ^/*$ %{DOCUMENT_ROOT}/w/index.php [L]

Change/move main page title

How to change MediaWiki “Main Page” title?

Registration time, password

Preferences > User Profile. From here we can see when the user has registered and there is an opportunity to change the password.


Top 15 downloaded extensions

Composer Composer is a dependency manager for PHP libraries. In addition, it can be used to manage the installation of MediaWiki extensions

This is asked by the GraphViz extension

Install Wikibase. MediaWiki-Docker/Extension/Wikibase. Get MediaWiki and extension files. Backing up data from Docker volumes. Backing up data using mysqldump.

$ composer install --no-dev
$ composer install <package>:<version> # install mediaWiki extension
$ composer install mediawiki/vector-skin:dev-REL1_35

Dockerfile from ubc/MediaWiki Docker Image. As we can see, the base image is php, not mediawiki (so it is very complicated). This follows the instruction described in

I guess an easy way to handle the missing default skins & extensions is by downloading the tarball and extract (& copy) the skins/extensions folders from there.

Google Analytics


NOTE: Not compatible with MediaWiki 1.33+. Consider an alternative Mermaid.

(tested on raspbian). The browser shows a message This page isn’t working XXX.XX.XX.XXX is currently unable to handle this request.

sudo apt install composer
nano composer.local.json
composer update

Run php maintenance/update.php shows PHP Fatal error: Uncaught ExtensionDependencyError: GraphViz requires ImageMap to be installed.

To fix the problem, I add wfLoadExtension( 'ImageMap' ); to LocalSettings.php. To cap,

wfLoadExtension( 'ImageMap' );

wfLoadExtension( 'GraphViz' );
$wgGraphVizExecPath = "/usr/bin";
$wgGraphVizMscgenPath = "/usr/bin";



See Math extension.



The 2nd line is required from my experience

wfLoadExtension( 'WikiEditor' );
$wgDefaultUserOptions['usebetatoolbar'] = 1;


Math extension

Examples of writing Math in mediawiki

Help:Displaying a formula from Lots of examples.


Mathoid server

Note: if I create a mathoid server on my host, probably other people can use it too.

Currently I am using the following options in LocalSettings.php,

wfLoadExtension( 'Math' );
$wgMathFullRestbaseURL= '';
$wgMathValidModes[] = 'mathml';

Note: we can check if a remote server port 10044 is open by using the command nc -vz RemoteDomain 10044. For example, nc -vz 10044 . If the port is open, it will show Connection to XXXX 10044 port [tcp/*] succeeded!

$ curl -XPOST -d'q=e=mc^2'

This should return JSON with 'mml' and 'svg' members..

So if I open a math equation in a new tab, it will show the link to (e.g. C-statistic) created in my Survival data page or link to if we don't specify $wgMathFullRestbaseURL. If I host mediawiki on Rasp Pi3, a mediawiki page with lots of math symbols will be too slow to be loaded. Also the source code of the math symbols linked from shows the math symbols are MathJax not MathML.

Also there is a rule on Wikimedia REST API: Limit your clients to no more than 200 requests/s to this API.

However, Ubuntu does not have a support on Mathoid which can convert math to SVG instead of PNG. Is that true?

I can only get PNG rendering for Math formula on Ubuntu. However if I use Mediawiki Docker image which based on PHP and PHP is based on Debian, I can get SVG images for Math formula.

If I go to Preferences > Appearance, the Math mode is "MathML with SVG or PNG fallback" in Docker but "PNG images" in Ubuntu. If I try to change to "MathML with SVG or PNG fallback" in Ubuntu, it will break.

Installing the MediaWiki Math extension is easier now (with a short instruction) March 2018.

Mathoid server on Ubuntu

The LocalSettings.php part

wfLoadExtension( 'Math' );
$wgMathValidModes[] = 'mathml';
$wgDefaultUserOptions['math'] = 'mathml';
$wgMathMathMLUrl = ''; # IP of Mathoid server

Note that installing npm on Rasp Pi 3B gives an error

$ sudo apt-get install nodejs nodejs-legacy nodejs-dev npm librsvg2-dev pkg-config
The following packages have unmet dependencies:
 nodejs : Conflicts: nodejs-legacy but 4.8.2~dfsg-1 is to be installed
E: Unable to correct problems, you have held broken packages.

Mathoid on Docker

Note. Using Docker has an advantage. On Raspberry Pi 3, I have a trouble to install nodejs and related packages.

$ sudo apt-get install nodejs nodejs-legacy nodejs-dev npm mocha librsvg2-dev pkg-config
The following information may help to resolve the situation:
The following packages have unmet dependencies:
 nodejs : Conflicts: nodejs-legacy but 4.8.2~dfsg-1 is to be installed
E: Unable to correct problems, you have held broken packages.

Tested on x86 Ubuntu (the "--restart unless-stopped" option can make the container automatically restart),

docker run -d --name mathoid -p 10044:10044 --restart unless-stopped nlpub/mathoid
# nc -vz localhost 10044
# Connection to localhost 10044 port [tcp/*] succeeded!
curl -XPOST -d'q=e=mc^2'  http://localhost:10044/

CLI interface Mathoid currently supports node version 6,8 or 10. To check your node version run node --version from the commandline.

This approach works on Ubuntu 16.04 & 18.04.

Some node.js experience is useful.

npm install

nvm - Node Version Manager

sudo apt install librsvg2-dev
curl -o- | bash
source .bashrc

# list node versions
nvm ls-remote
# install a specific version of node
nvm install 10.16.3
nvm uninstall 12.11.0 # from my previous mistake of installing the latest
nvm list  # list the available Node.js versions locally
# nvm use 10.16.3
nvm use node
node --version  # v10.16.3

nvm install-latest-npm # OR nvm install --latest-npm
git clone
cd mathoid
npm install
npm audit fix --force
npm install acorn
npm install ajv
# The version number below may change
sudo cp ~/.nvm/versions/node/v10.16.3/bin/node /usr/local/bin/
npm test # fail but it is OK
nano mediawiki-1.33.0/LocalSettings.php

The double vertical symbols should be replaced by \| or \Vert; otherwise, the page cannot be loaded. See Fractions, matrices, multilines.

Embed images (math equations) from URL

It is possible to create latex equation on online and get a URL link. See Equations in HTML (SVG + GIF) from The source code of the equation image shows an SVG tag was used just like the Math extension did.

The following two options are needed in LocalSettings.php

$wgAllowExternalImages = true;
$wgAllowImageTag = true;

The wgAllowImageTag allows to resize the image. See the following example

<img src="" width="100">

<img src="" border="0"/>



Another way to get the SVG instead of PNG format for mathematical formulae is to use the SimpleMathJax extension (see a discussion). SimpleMathJax is better than Math because when I use Math the node program will periodically run some program with all CPU cores.

The instruction needs to be modified.

  • After unzip the zip file to the extensions folder it is necessary to change the folder name from 'SimpleMathJax-master' to 'SimpleMathJax' (if we did not do that, the maintenance/update.php will issue errors)
  • The renaming step is not necessary if we use the 'git' command to download the files; i.e. git clone
  • If I turn off the internet and modify a math equation, it won't be able to interpret the math equation.

It works when I tested on Ubuntu 18 + Mediawiki 1.31 + SimpleMathJax 0.7.3.

root@ubuntu1804:/var/www/html/mediawiki/extensions# ls -lh SimpleMathJax/
total 20K
-rw-r--r-- 1 root root  829 May 12 11:47 extension.json
drwxr-xr-x 3 root root 4.0K May 12 11:47 modules
-rw-r--r-- 1 root root 1.7K May 12 11:47
-rw-r--r-- 1 root root 1.3K May 12 11:47 SimpleMathJax_body.php
-rw-r--r-- 1 root root  391 May 12 11:47 SimpleMathJax.php

How to display index under the sigma sign




<span class="texhtml mvar" style="font-style:italic;">{{{1}}}</span>

Create a new Template page

Suppose I want to create a template called "Template:Pre". I can go to URL and type The mediawiki will offer me choices and one of them is to create this page.

I use this way to create a shortcut that I can use by using {{Pre}} to replace a long typing of Preformatted text with text wrap.

Trouble shooting


Convert images

error creating thumbnail, imagemagick, inkscape

includes/shell/ line 101: 3788 Aborted /usr/bin/timeout $MW_WALL_CLOCK_LIMIT

  1. I create another mediawiki directory. It is best to copy and create a new database instead of using the same database.
  2. Follow Manual:How to debug mediawiki by modify LocalSettings.php file
  3. Open the log file in VS code. Search 'convert' or the filename I uploaded. I see the error comes from executing the line convert -background "#ffffff00" -thumbnail 600x600\! temp3.svg PNG:'temp3.png'
  4. I can repeat the error by executing the command in a terminal on Ubuntu 16.04. But the same command works fine on Ubuntu 18.04
  5. I follow the instruction How to install ImageMagick 7 on Ubuntu 18.04 Linux to compile imageMagick source code on Ubuntu 16.04. Very simple.
  6. I uninstall the old imagemagick.
  7. The new commands will be available on /usr/local/bin. They will be available once I log out and log in again to the system.
  8. Re-try the command to convert a SVG image. It works now.

Google: "how to convert a svg to a png with ImageMagick?" OR "svg to png not converting text" returns several results. It seems ImageMagick with a problem with the SVG engine. inkscape works great with vector images (better than ImageMagikk’s convert).

My conclusion is to use the png format instead for mediawiki. (CairoSVG() does not help. I've also tried to build ImageMagick from source on Ubuntu 20.04. Building is easy but the converted png file though no error was given - the source is svg) Left is the correct. Right is converted. Also the svg file saved by the svglite package also has its own problem. The conversion does not give any error but the png file gives black on the plot region:( This online tool like can convert my svg file correct but can't.

svglite::svglite("colorspace.svg", width=8, height=6)
hcl_palettes(palette = "Dark 2", n=5, plot = T)

Inter gg.png Inter gg2.png

"non-conforming drawing primitive definition" error. You are likely using the internal ImageMagick MSVG renderer, which is not as advanced as RSVG delegate or Inkscape. However, inkscape is not working well in a headless system; see my note at Inkscape error.

Manual:Common errors and symptoms from Mediawiki

Manual:$wgSVGConverters & Manual:$wgSVGConverter from Mediawiki

SVG_help. It provides some explanation and solutions.

Import images

$ php maintenance/dumpUploads.php | grep Boxplot
$ find images -iname *Boxplot*
# Get a list of uploaded images, save them to a new folder
php maintenance/dumpUploads.php | grep images | xargs tar czvf ~/Downloads/backup_files.tar.gz
mkdir ~/Downloads/imagesdir
tar xzvf backup_files.tar.gz -C ~/Downloads/imagesdir
cd ~/Downloads/imagesdir
find images -type f -exec cp {} . \;
rm *.txt
rm *.pdf
rm -rf images

# scp imagesdir to my local computer. Then run
php maintenance/importImages.php --overwrite /mnt
# where imagesdir has been mounted to /mnt
# For some reason, some images are not imported?
chown -R www-data:www-data images

Fatal exception of type "Wikimedia\Rdbms\DBQueryError"

Run php update.php.

New version of images don't trigger thumbnail recreation

Using chrome's inspection I see the thumbnail files location. If I check those thumbnail files they are updated on the server. But it seems the server kept a cache of the file for a certain resolution of thumbnails somewhere. Even I reboot the server, certain resolution of thumbnail image file is still the old one.

Since no solution is found, it is better to use the admin to delete the file and update a different filename of the same file again.

Delete upload files

  1. Ensure you have "sysop" permissions and you're logged in.
  2. Select "Special Pages" from the toolbox on the left-hand side of the screen.
  3. Click on "Unused files" or "File list," depending on whether you want to delete an unused file or see all the files uploaded to the wiki.
  4. Find the file you wish to delete.
  5. Go to the file history at the bottom of the file page.
  6. Now click "(Delete all revisions of this file)" or just one specific version of the file if multiple versions exist.
  7. Confirm your choice and provide a reason for the deletion.

Deleting revisions

See Working with MediaWiki

There seems to be a problem with your login session; this action has been canceled as a precaution against session hijacking

The problem happens on my RasPi backup.

The solution is Adding $wgCookieSecure = false; to the bottom of my LocalSettings.php; see Cookie problem.

Backup for offline

wget -k -p -r -R '*Special*' -R '*Help*' -E

How to move a MediaWiki wiki from one server to another

how to move a MediaWiki wiki from one server to another

Mediawiki to Markdown

How to Create Your Own Offline Wiki

Comparison of wiki hosting services

Use Github Wiki


Clean up headers

I use a small R script to clean up the header levels. Normally the header should start with one "=".

x <- readLines("~/Downloads/linux.txt")
# Manual check possible header levels

# The original source (eg Ubuntu) may be messed up
# Most are starting with '===' but two are starting from '=='
# In that case, we need to fix the source first
# This solves the mystery that TOC does not show up in mobile device
cnt <- 0
ind <- grep("^== ", x)
if (length(ind) > 1) {
  cat("Number of ==", length(ind), "\n")
  cnt <- cnt + 1L
  x[ind] <- gsub("==", paste0(rep("=", cnt), collapse = ""), x[ind])

# The rule may fail if '===' occurs in a preformated text/code
# In this case we can safely ignore the cases.
ind <- grep("^=== ", x)
if (length(ind) > 1) {
  cat("Number of ===", length(ind), "\n")
  cnt <- cnt + 1L
  x[ind] <- gsub("===", paste0(rep("=", cnt), collapse = ""), x[ind])

ind <- grep("^==== ", x)
if (length(ind) > 1) {
  cat("Number of ====", length(ind), "\n")
  cnt <- cnt + 1L
  x[ind] <- gsub("====", paste0(rep("=", cnt), collapse = ""), x[ind])

ind <- grep("^===== ", x)
if (length(ind) > 1) {
  cat("Number of =====", length(ind), "\n")
  cnt <- cnt + 1L
  x[ind] <- gsub("=====", paste0(rep("=", cnt), collapse = ""), x[ind])
writeLines(x, "~/Downloads/linux2.txt")

Convert to markdown