< Wiki Farms | Documentation Index | Troubleshooting >

This page will attempt to summarize some of the more commonly asked questions. The answers are on the corresponding pages (see link). If you have a question which isn't answered here, you can leave your question on the Questions page or search for documentation using the search facility. More documentation can be found on the documentation index page.


What is PmWiki?

PmWiki is a wiki-based system for collaborative creation and maintenance of websites. See PmWiki.

What can I do with it?

PmWiki pages look and act like normal web pages, except they have an "Edit" link that makes it easy to modify existing pages and add new pages into the website, using basic editing rules. You do not need to know or use any HTML or CSS. Page editing can be left open to the public or restricted to small groups of authors. Feel free to experiment with the Text Formatting Rules in the "Wiki sandbox". The website you're currently viewing is built and maintained with PmWiki.

What are the requirements?

See the PmWiki requirements page.

Where can I find documentation?

See the documentation index page.

How can I download PmWiki?

See the download page.

How do I install PmWiki?

Instructions for installation are on the installation page.

How do I get help with PmWiki?

See Mailing lists and How to get assistance.

How do you pronounce "Michaud"?

"Michaud" is french pronounced "mee show", the trailing D is silent.

Basic PmWiki editing rules

I'm new to PmWiki, where can I find some basic help for getting started?

The Basic Editing page is a good start. From there, you can just follow the navigational links at the top or the bottom of the page (they are called Wiki Trails) to the next pages, or to the Documentation Index page, which provides an outline style index of essential documentation pages, organized from basic to advanced.

How do I include special characters such as Copyright (©) and Trademark (® or ™) on my wiki pages?

See special characters on how to insert special characters that don't appear on your keyboard.

How can I preserve line-breaks from the source text?

PmWiki normally treats consecutive lines of text as being a paragraph, and merges and wraps lines together on output. This is consistent with most other wiki packages. An author can use the (:linebreaks:) directive to cause the following lines of markup text in the page to be kept as separate lines in the output. Or a wiki administrator can set in config.php $HTMLPNewline = '<br/>'; to force literal new lines for the whole site.

Can I just enter HTML directly?

By default (and by design), PmWiki does not support the use of HTML elements in the editable markup for wiki pages. There are a number of reasons for this described in the PmWiki Philosophy and Audiences. Enabling HTML markup within wiki pages in a collaborative environment may exclude some potential authors from being able to edit pages, and pose a number of display and security issues. However, a site administrator can use the Cookbook:Enable HTML recipe to enable the use of HTML markup directly in pages.

Where can I find more documentation?

See the documentation index and the markup master index pages.


How do I create a link that will open as a new window?

Use the %newwin% wikistyle, as in:

%newwin% http://example.com/ %%


How do I create a link that will open a new window, and configure that new window?

This requires javascript. See Cookbook:PopupWindow.

How do I place a mailing address in a page?

Use the mailto: markup, as in one of the following:

* mailto:myaddress@example.com
* [[mailto:myaddress@example.com]]
* [[mailto:myaddress@example.com | email
subject | email me]]

The markup [[mailto:me@example.com?cc=someoneelse@example.com&bcc=else@example.com&subject=Pre-set Subject&body=Pre-set body | display text]] =] lets you specify more parameters like the message body and more recipients (may not work in all browsers and e-mail clients).

See also Cookbook:DeObMail for information on protecting email addresses from spammers.

How can I enable links to other protocols, such as nntp:, ssh:, xmpp:, etc?

See Cookbook:Add Url schemes

How do I make a WikiWord link to an external page instead of a WikiPage?

Use link markup. There are two formats:

[[http://example.com/ | WikiWord]]
[[WikiWord -> http://example.com/]]

How do I find all of the pages that link to another page (i.e., backlinks)?

In the wiki search form, use link=Group.Page to find all pages linking to Group.Page.

Use the link= option of the (:pagelist:) directive, as in

(:pagelist link=SomePage list=all:)   -- show all links to SomePage
(:pagelist link={$FullName} list=all:)  -- show all links to the current page

What link schemes does PmWiki support?

See PmWiki:Link schemes

How do I open external links in a new window or mark them with an icon?

See Cookbook:External links

How can I use an image as a link?

Use [[Page| Attach:image.jpg ]] or [[ http://site | http://site/image.jpg ]] See Images#links

Why my browser does not follow local file:// links?

For security reasons, most browsers will only enable file:// links if the page containing the link is itself on the local drive. In other words, most browsers do not allow links to file:// from pages that were fetched using http:// such as in a PmWiki site. See also Cookbook:DirList for a workaround.


When I upload a file, how do I make the link look like "file.doc" instead of "Attach:file.doc Δ"?

Use parentheses, as in [[(Attach:)file.doc]]. There is also a configuration change that can eliminate the Attach: -- see Cookbook:AttachLinks.

Why can't I upload files of size more than 50kB to my newly installed PmWiki?

Out of the box PmWiki limits the size of files to be uploaded to 50kB. Add

$UploadMaxSize = 1000000; # limit upload file size to 1 megabyte
to your config.php to increase limit to 1MB (for example). See UploadsAdmin for how to further customize limits. Note that both PHP and webservers also place their own limits on the size of uploaded files.

Why does my upload exit unexpectedly with "Incomplete file received"?

You may be running out of space in a 'scratch' area, used either by PmWiki or by PHP. On *nix, check that you have sufficient free space in /tmp and /var/tmp.

How do I make it so that the upload link still allows one to make another upload (if someone wants to replace the old version of a file with a newer version, for example). Currently you only get the upload link when there is no file in the upload directory.

Use the Attach page action, and click on the delta symbol (Δ) shown against each of files listed. If you can't see the attach action either uploads are not enabled, you are not not authorized to upload, or the attach action has been commented out or is missing. See also available actions.

How do I hide the "Attach:" for all attachments

See Cookbook:AttachLinks, note that this does not currently work for [[Attach:my file.ext]] .

How to avoid problems with non-ASCII characters in attachment names (i.e. "Zażรณłć geślą jaźń.doc")?

See $UploadNameChars = "-\w. !=+#"; # allow exclamations, equals, plus, and hash

How can I link a file that have a 4-letter file extension such like 'abc.pptx'?

See Cookbook:Upload Types

How can I prevent others from using the url's of my images on their site

See Cookbook:Prevent Hotlinking


How do I create a basic table?

Tables are created via use of the double pipe character: ||. Lines beginning with this markup denote rows in a table; within such lines the double-pipe is used to delimit cells. In the examples below a border is added for illustration (the default is no border).

Basic table
|| border=1 rules=rows frame=hsides
|| cell 1 || cell 2 || cell 3 ||
|| cell 1 || cell 2 || cell 3 ||
cell 1cell 2cell 3
cell 1cell 2cell 3

How do I create cell headers?

Header cells can be created by placing ! as the first character of a cell. Note that these are table headers, not headings, so it doesn't extend to !!, !!!, etc.

Table headers
|| border=1 rules=cols frame=vsides
||! cell 1 ||! cell 2 ||! cell 3 ||
|| cell 1  ||  cell 2 ||  cell 3 ||
cell 1cell 2cell 3
cell 1cell 2cell 3

How do I obtain a table with thin lines and more distance to the content?

"Thin lines" is tricky and browser dependent, but the following works for Firefox and IE (Nov. 2009):

Thin lines and cell padding
cellpadding="5" width=66%
||!Header ||! Header || '''Header'''||
||cells   ||  with   ||      padding||
||        ||         ||             ||

How do I create an advanced table?

See table directives

My tables are by default centered. When I try to use '||align=left' they don't align left as expected.

Use ||style="margin-left:0px;" instead.

How can I specify the width of columns?

You can define the widths via custom styles, see Cookbook:FormattingTables and $TableCellAttrFmt. Add in config.php : $TableCellAttrFmt = 'class=col$TableCellCount';

And add in pub/css/local.css :
table.column td.col1 { width: 120px; }
table.column td.col3 { width: 40px; }

How can I display a double pipe "||" in cell text using basic table markup?

Escape it with [=||=] to display || unchanged.

How to I apply styles to the elements of the table, like an ID to the table row, or a class/style to the TD?

See $WikiStyleApply.

Table directives

Can I define table headers using the table directive markup?

Yes, with PmWiki version 2.2.11 or newer. See also Cookbook:AdvancedTableDirectives.

Is it possible to do nested tables?

Yes, if you nest simple tables inside advanced tables. See also Cookbook:AdvancedTableDirectives.

Is it possible to add background images to tables and table cells?

Yes, see Cookbook:BackgroundImages.

Is it possible to apply styles to the elements of the table, like an ID to the table row, or a class/style to the TD?

Yes, see $WikiStyleApply.


How can I change the keyboard shortcuts for editing and saving a page?

See Customizing access keys.


Can I get (:redirect:) to return a "moved permanently" (HTTP 301) status code?

Use (:redirect PageName status=301:).

Is there any way to prevent the "redirected from" message from showing at the top of the target page when I use (:redirect:)?

From version 2.2.1 on, set in config.php $EnableRedirectQuiet=1; and in the page (:redirect OtherPage quiet=1:) for a quiet redirect.

Is there any method for redirecting to the equivalent page in a different group, i.e. from BadGroup/thispage => GoodGroup/thispage using similar markup to (:redirect Goodgroup.{Name}:)?

(:redirect Goodgroup.{$Name}:) works if you want to put it in one page.
If you want it to work for the entire group, put (:redirect Goodgroup.{*$Name}:) into Badgroup.GroupHeader - however, that only works with pages that really exist in Goodgroup; if you visit a page in Badgroup without a corresponding page of the same name in Goodgroup, instead of being redirected to a nonexistant page, you get the redirect Directive at the top of the page.
With (:if exists Goodgroup.{*$Name}:)(:redirect Goodgroup.{*$Name}:)(:ifend:) in Badgroup.GroupHeader you get redirected to Goodgroup.Name if it exists, otherwise you get Badgroup.Name without the bit of code displayed.

How can a wiki enable linebreaks by default, i.e. without having the directive (:linebreaks:) in a page or in a GroupHeader?

Add to config.php such a line:
$HTMLPNewline = '<br/>';


What's the maximum number of includes that can exist in a page?

My site seems to stop including after 48 includes. ($MaxIncludes)

By default, PmWiki places a limit of 50 include directives for any given page, to prevent runaway infinite loops and other situations that might eat up server resources. (Two of these are GroupHeader and GroupFooter.) The limit can be modified by the wiki administrator via the $MaxIncludes variable.

Is there any way to include from a group of pages without specifying by exact name, e.g. between Anchor X and Y from all pages named IFClass-* ?

This can be achieved using page lists.

There appears to be a viewing issue when the included page contains the (:title:) directive.

In a default installation, the last title in the page overrides previous ones so you can place your (:title :) directive at the bottom of the page, after any includes. See also $EnablePageTitlePriority.

Page specific variables

Is there a variable like $LastModified, but which shows me the creation time?

No, but you can create one in config.php. For instance:

# add page variable {$PageCreationDate} in format yyyy-mm-dd
$FmtPV['$PageCreationDate'] = 'strftime("%Y-%m-%d", $page["ctime"])';

If you like the same format that you define in config.php with $TimeFmt use

 $FmtPV['$Created'] = "strftime(\$GLOBALS['TimeFmt'], \$page['ctime'])";


How do I set the same header or footer for all pages/groups?

The header and footer for each page are controlled by the variables $GroupHeaderFmt and $GroupFooterFmt. If your site-wide header and footer pages are Site.SiteHeader and Site.SiteFooter, you can add this in config.php:

### If you use Site.SiteHeader and Group.GroupHeader
$GroupHeaderFmt = '(:include {$SiteGroup}.SiteHeader'
  . ' basepage={*$FullName}:)(:nl:)' . $GroupHeaderFmt;

### If you use Site.SiteHeader instead of Group.GroupHeader
$GroupHeaderFmt = '(:include {$SiteGroup}.SiteHeader'
  . ' basepage={*$FullName}:)(:nl:)';

### If you use Site.SiteFooter and Group.GroupFooter
$GroupFooterFmt .= '(:nl:)(:include {$SiteGroup}.SiteFooter'
  . ' basepage={*$FullName}:)';

### If you use Site.SiteFooter instead of Group.GroupFooter
$GroupFooterFmt = '(:nl:)(:include {$SiteGroup}.SiteFooter'
  . ' basepage={*$FullName}:)';

Note that single quotes must be used in the lines above.

See also the Cookbook:AllGroupHeader recipe.

Instead of using an additional page, you could set any wiki text in $GroupHeaderFmt, for example:

$GroupHeaderFmt .= "Global message here.";


Is there a way to remove page history from page files?

1. Administrators can clean page histories using the Cookbook:ExpireDiff recipe.

2. Administrators with FTP file access can download individual pages from the wiki.d directory, open them in a text editor, manually remove history, and re-upload the files to wiki.d/ directory. Care must be exercised, when manually editing a page file, to preserve the minimum required elements of the page and avoid corrupting its contents. See PageFileFormat#creating.

3. Edit the page. Select all the contents of the edit text area and cut them to the clipboard. Enter delete into the text area and click on the save and edit button. Select all the contents of the edit text area and paste the contents of the clipboard over them. Click on the save button. This will remove all of the page's history up to the final save in which the pasted material is re-added.

How can I restrict viewing the page history (?action=diff) to people with edit permission?

In the local/config.php file, set

$HandleAuth['diff'] = 'edit';

In case of this restriction is set up on a farm, and you want to allow it on a particular wiki, set in your local/config.php :

$HandleAuth['diff'] = 'read';


How can I password protect all the pages and groups on my site? Do I really have to set passwords page by page, or group by group?

Administrators can set passwords for the entire site by editing the config.php file; they don't have to set passwords for each page or group. For example, to set the entire site to be editable only by those who know an "edit" password, an administrator can add a line like the following to local/config.php:

    $DefaultPasswords['edit'] = crypt('edit_password');

For more information about the password options that are available only to administrators, see PasswordsAdmin.

I get http error 500 "Internal Server Error" when I try to log in. What's wrong?

This can happen if the encrypted passwords are not created on the web server that hosts the PmWiki.
The crypt function changed during the PHP development, e.g. a password encrypted with PHP 5.2 can not be decrypted in PHP 5.1, but PHP 5.2 can decrypt passwords created by PHP 5.1.
This situation normally happens if you prepare everything on your local machine with the latest PHP version and you upload the passwords to a webserver which is running an older version.
The same error occurs when you add encrypted passwords to local/config.php.

Solution: Create the passwords on the system with the oldest PHP version and use them on all other systems.

How can I create private groups for users, so that each user can edit pages in their group, but no one else (other than the admin) can?

Modify the edit attribute for each group to id:username, e.g. set the edit attribute in JaneDoe.GroupAttributes to id:JaneDoe.

There is a more automatic solution, but it's probably not a good idea for most wikis. Administrators can use the AuthUser recipe and add the following few lines to their local/config.php file to set this up:

    $group = FmtPageName('$Group', $pagename); 
$DefaultPasswords['edit'] = 'id:'.$group;

This automatically gives edit rights to a group to every user who has the same user name as the group name. Unfortunately it also gives edit rights to such a user who is visiting a same-named group not just for pages in that group, but for any page on the wiki that relies on the site's default edit password. This can create security holes.

How come when I switch to another wiki within a farm, I keep my same authorization?

PmWiki uses PHP sessions to keep track of authentication/authorization information, and by default PHP sets things up such that all interactions with the same server are considered part of the same session.

An easy way to fix this is to make sure each wiki is using a different cookie name for its session identifier. Near the top of one of the wiki's local/config.php files, before calling authuser or any other recipes, add a line like:


You can pick any alphanumeric name for XYZSESSID; for example, for the cs559-1 wiki you might choose


This will keep the two wikis' sessions independent of each other.

PmWiki Installation

Should I rename pmwiki.php to index.php?

Renaming pmwiki.php is not recommended. Instead, create an index.php file that contains this single line

<?php include_once('pmwiki.php');

How do I make pmwiki.php the default page for a website?

Create an index.php file that runs PmWiki from a subdirectory (pmwiki/ for example) and place it in the site's web document root (the main directory for the website).

<?php chdir('pmwiki'); include_once('pmwiki.php');

Note: You will also need to explicitly set the $PubDirUrl variable (e.g. to "http://example.com/pmwiki/pub") in local/config.php .

How do I enable "Clean URLs" that are shorter and look like paths to my wiki pages? Why does pmwiki.org appear to have a directory structure rather than "?n=pagename" in URLs?

See Cookbook:CleanUrls.

How can I run PmWiki on a standalone (offline, portable) machine ?

See Cookbook:Standalone or Cookbook:WikiOnAStick.

Uploads Administration

How do I disable uploading of a certain type of file?

Here's an example of what to add to your local/config.php file to disable uploading of .zip files, or of files with no extension:

$UploadExtSize['zip'] = 0;  # Disallow uploading .zip files
$UploadExtSize[''] = 0;     # Disallow files with no extension

How do I attach uploads to individual pages or the entire site, instead of organizing them by wiki group?

Use the $UploadPrefixFmt variable (see also the Cookbook:UploadGroups recipe).

$UploadPrefixFmt = '/$FullName'; # per-page, in Group.Name directories
$UploadPrefixFmt = '/$Group/$Name'; # per-page, in Group directories with Name subdirectories
$UploadPrefixFmt = ''; # site-wide

For $UploadDirQuota - can you provide some units and numbers? Is the specification in bytes or bits? What is the number for 100K? 1 Meg? 1 Gig? 1 Terabyte?

Units are in bytes.

   $UploadDirQuota = 100*1024;         # limit uploads to 100KiB
   $UploadDirQuota = 1000*1024;        # limit uploads to 1000KiB
   $UploadDirQuota = 1024*1024;        # limit uploads to 1MiB
   $UploadDirQuota = 25*1024*1024;     # limit uploads to 25MiB
   $UploadDirQuota = 2*1024*1024*1024; # limit uploads to 2GiB

Is there a way to allow file names with Unicode or addtiional characters?

Yes, see $UploadNameChars

Where is the list of attachments stored?

It is generated on the fly by the


    How can I find orphaned or missing attachments

    For older versions of PmWiki, see Cookbook:Attachlist enhanced "",
    for version 2.2 or higher see Cookbook:Attachtable ""

    How can I prevent hotlinking of my uploaded images

    See Cookbook:Prevent Hotlinking

    I have limited the max upload size to 8 MB in config.php, however only files smaller than 2MB can be uploaded.

    Check your php.ini for upload_max_filesize

    upload_max_filesize = 8M

    If you cannot access your php.ini directly try to soften server limits in the root .htaccess file:

    php_value post_max_size 63M
    php_value upload_max_filesize 62M
    php_value memory_limit 64M
    php_value max_execution_time 600
    php_value default_socket_timeout 600

    How can I upload multiple files at once?

    See the following recipes: DragDropMultiUpload, MultiUpload, UploadForm.


    How do I report a possible security vulnerability of PmWiki?

    Pm wrote about this in a post to pmwiki-users from September 2006. In a nutshell he differentiates two cases:

    1. The possible vulnerability isn't already known publicly: In this case please contact Pm by private mail.
    2. The possible vulnerability is already known publicly: In this case feel free to discuss the vulnerability in public (e.g. on pmwiki-users).

    See his post mentioned above for details and rationals.

    What about the botnet security advisory at http://isc.sans.org/diary.php?storyid=1672?

    Sites that are running with PHP's register_globals setting set to "On" and versions of PmWiki prior to 2.1.21 may be vulnerable to a botnet exploit that is taking advantage of a bug in PHP. The vulnerability can be closed by turning register_globals off, upgrading to PmWiki 2.1.21 or later, or upgrading to PHP versions 4.4.3 or 5.1.4.
    In addition, there is a test at PmWiki:SiteAnalyzer that can be used to determine if your site is vulnerable.

    Wiki Vandalism and Spam

    you are using a Blocklist and Url approvals.
    You don't want to resort to password protecting the entire wiki, that's not the point after all.
    Ideally these protections will be invoked in config.php

    How do I stop pages being deleted, eg password protect a page from deletion?

    Use Cookbook:DeleteAction and password protect the page deletion action by adding $DefaultPasswords['delete'] = '*'; to config.php or password protect the action with $HandleAuth['delete'] = 'edit';

    or $HandleAuth['delete'] = 'admin'; to require the edit or admin password respectively.

    How do I stop pages being replaced with an empty (all spaces) page?

    Add block: /^\s*$/ to your blocklist.

    how do I stop pages being completely replaced by an inane comment such as excellent site, great information, where the content cannot be blocked?

    Try using the newer automatic blocklists that pull information and IP addresses about known wiki defacers.

    (OR) Try using Cookbook:Captchas or Cookbook:Captcha (note these are different).

    (OR) Set an edit password, but make it publicly available on the Site.AuthForm template.

    How do I password protect the creation of new groups?

    See Cookbook:Limit Wiki Groups

    How do I password protect the creation of new pages?

    See Cookbook:Limit new pages in Wiki Groups

    How do I take a whitelist approach where users from known or trusted IP addresses can edit, and others require a password?

    Put these lines to local/config.php:

    ## Allow passwordless editing from own turf, pass for others.
    if ($action=='edit'
     && !preg_match("/^90\\.68\\./", $_SERVER['REMOTE_ADDR']) )    
     { $DefaultPasswords['edit'] = crypt('foobar'); }

    Replace 90.68. with the preferred network prefix and foobar with the default password for others.

    How do I password protect page actions?

    See Passwords for setting in config.php

    $HandleAuth['pageactionname'] = 'pageactionname'; # along with :
    $DefaultPasswords['pageactionname'] = crypt('secret phrase');


    $HandleAuth['pageactionname'] = 'anotherpageactionname';

    How do I moderate all postings?

    Enable PmWiki.Drafts

    • Set $EnableDrafts, this relabels the "Save" button to "Publish" and a "Save draft" button appears.
    • Set $EnablePublishAttr, this adds a new "publish" authorization level to distinguish editing from publishing.

    How do I make a read only wiki?

    In config.php set an "edit" password.

    How do I restrict access to uploaded attachments?



    How can I embed JavaScript into a page's output?

    There are several ways to do this. The Cookbook:JavaScript recipe describes a simple means for embedding static JavaScript into web pages using custom markup. For editing JavaScript directly in wiki pages (which can pose various security risks), see the JavaScript-Editable recipe. For JavaScript that is to appear in headers or footers of pages, the skin template can be modified directly, or