FAQ

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.

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 new page?

Typing [[my new page]] will create a link to the new page. There's a lot you can do with double bracket links.

Why do some new pages have a title with spaces like "Creating New Pages" and others end up with a WikiWord-like title like "CreatingNewPages"?

The default page title is simply the name of page, which is normally stored as "CreatingNewPages." However, you can override a page's title by using the (:title Creating New Pages:) directive. This is especially useful when there are special characters or capitalization that you want in the title that cannot be used in the page name.

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

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 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 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 can I display a file that lacks a correct extension? (e.g. you are using Cookbook:LinkIcons)

A file can be displayed by addition of a "false" extension to the URL. For example, if the url is https://example.com/dox/mydoc, add a fake query string on the end with the desired extension (e.g., https://example.com/dox/mydoc?format=.docx). If query strings are unsuitable, a fragment identifier should work, e.g. https://example.com/dox/mydoc#.docx.

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).

|| border=1 rules=rows frame=hsides
|| cell 1 || cell 2 || cell 3 ||
|| cell 1 || cell 2 || cell 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.

|| border=1 rules=cols frame=vsides
||! cell 1 ||! cell 2 ||! cell 3 ||
|| cell 1  ||  cell 2 ||  cell 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):

||border="1" style="border-collapse:collapse" 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';

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 do 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.

Alternately, use table directives, which allow specifying styling either directly (style="...") or by a class="..." attribute for CSS.

Is there a simple way to change the table defaults? I prefer a border and I'm tired of adding it to every table.

You can set $SimpleTableDefaultClassName = 'simpletable'; and/or define your own styles in your stylesheet. The "simpletable" class is available in the core skins, and can be redefined or overridden in pub/css/local.css.

Can I define table headers using the table directive markup?

Yes, use (:head:) or (:headnr:) 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.

Is it possible to automatically generate columns or rows in tables, i.e. without having to do a lot of counting?

Yes, this is possible with the Cookbook:CreateColumns recipe - it allows you to specify a certain number of columns, and/or to specify a certain number of items per column. Plus, someone has provided some similar markup on the TableDirectives-Talk page.

Is it possible to use table captions in table directives similar to simple tables? Tried ! Captiontext ! and (:caption:) . Didn#t work. How to do?

Yes, this is possible with the Cookbook:AdvancedTableDirectives recipe - There you will find a (:caption:) directive.

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}:)?

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/>';

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'] = '[[PmWiki/Functions#PSFT|PSFT]]("[=%Y-%m-%d=]", $page["ctime"])';

How can I test if a variable is set and/or not empty?

Use [=(:if ! equal "{$Variable}" "":) $Variable is not empty. (:ifend:)=]. Note that undefined/inexistent variables appear as empty ones.

Categories: PmWiki Developer

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:

What's the difference between a PageList and a WikiTrail?

The pagelist directive dynamically generates a list of pages. There are many ways to generate the list, including using a WikiTrail as the source.
The pagelist directive then displays the pages that match the criteria using an optional template - for example displaying each page name on a separate line as a link or including the entire content.
The pagelist directive currently does not have built-in navigation markup that you can put on the pages in the list.
By contrast, WikiTrails are simply specified via links on an "index" page and you can put previous-next navigation markup on each page. The two serve very different purposes. WikiTrails are useful for specifying the pages in web feeds, for creating a "tour" through a predefined set of pages, and many other things.

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:

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 PHP 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;
include_once("$FarmD/scripts/authuser.php"); 

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.
For security considerations about shared session pools, see the "Session injection" chapter in Cookbook:SessionSecurityAdvice.
To fix the browser-side convenience issue, one easy way is to make sure each wiki uses 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' session cookies independent of each other.

Is it possible to test the password level for display and/or if condition? Example: * (:if WriterPassword:) (display Edit link) (:ifend:)

You can use (:if auth edit:). See ConditionalMarkup.

Can I use (:if …:) to hide secrets in a wiki page?

You can, but usually that's not secure. The recommended strategy is to put secrets in a separate page and restrict all read-related¹ access permissions to those users who are allowed to read the secrets. To display the secrets in another page, you can include (parts of) the secrets page: Users with read access to the secrets will readily see them, whereas other users see nothing or (at your choosing) some other text, e.g. a login link.

The reason why Conditional Markup isn't suitable for access control is that it only applies for rendering wikitext as a web page, and that's just one of many ways to access a page's text. In order to rely on Conditional Markup for protection of secrets, you'd have to restrict all access methods that can circumvent it. To do so, you'd need to keep track of all methods available. In a default installation of PmWiki, some of the easy methods include: Editing a page, viewing its edit history, its source, or including fragments of it into the edit preview of another page. (Preview: To avoid traces in RecentChanges.) However, this list is far from exhaustive, and could easily grow with Recipes? or future versions of PmWiki.

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 us 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 or in the PITS).

See his post mentioned above for details and rationals.

What about the botnet security advisory at https://isc.sans.edu/diary/Reports+of+Bots+exploiting+pmwiki+and+tikiwiki/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

Assumptions

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';

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'] = pmcrypt('foobar'); }

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

For a single IP, you may use

if($_SERVER['REMOTE_ADDR'] == '127.0.0.1') { # your IP address here
 $_POST['authpw'] = 'xxx';                  # the admin password
}

Please note the security issues: this means that you have your admin passwords in clear in config.php and someone with access to the filesystem can read them (for example a technician of your hosting provider); your IP address may change from time to time (unless you have a fixed IP contract with your ISP). When that happens, someone with your old IP address will be logged in automatically as admin on your wiki. It is extremely unlikely to become a problem, but you should know it is possible; if you are behind a router, all other devices which pass through that router will have the same IP address for PmWiki - your wifi phone, your wife's netbook, a neighbour using your wifi connection, etc. All these people become admins of your wiki. Again, you should evaluate if this is a security risk; In some cases, your ISP will route your traffic through the same proxy as other people. In such a case, thousands of people may have the same IP address.

See also Cookbook:AuthDNS & Cookbook:PersistentLogin

How do I password protect page actions?

See Passwords for setting in config.php

or

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?

See

• instructions for denying public access to the uploads directory
• Cookbook:Secure attachments

How do I hide the IP addresses in the "diff" pages?

If the user fills an author name, the IP address is not displayed. To require an author name, set in config.php such a line:

  $EnablePostAuthorRequired = 1;

The IP address can also be seen in a tooltip title when the mouse cursor is over the author name. To disable the tooltip, set in config.php:

$DiffStartFmt = 
  "<div class='diffbox'><div class='difftime'><a name='diff\$DiffGMT' href='#diff\$DiffGMT'>\$DiffTime</a>
   \$[by] <span class='diffauthor'>\$DiffAuthor</span> - \$DiffChangeSum</div>";

How do I stop some Apache installations executing a file which has ".php", ".pl" or ".cgi" anywhere in the filename

Use $UploadBlacklist

How do I stop random people from viewing the ?action=source (wiki markup) of my pages? I have (:if auth edit:) text that I don't want the world to see.

$HandleAuth['source'] = 'edit'; or $HandleAuth['source'] = 'admin';

How to I secure my cookies?

See $EnableCookieSecure and $EnableCookieHTTPOnly

How do I set a global password to resist spambots, and informed humans of the password?

See Cookbook:OpenPass-Talk

How can I apply CSS styles to a particular group or page?

Simply create a pub/css/Group.css or pub/css/Group.Page.css file containing the custom CSS styles for that group or page. See also Cookbook:LocalCSS.

Why shouldn't passwords be set in group (or page) customization files? Why shouldn't group or page passwords be set in config.php?

The reason for this advice is that per-group customization files are only loaded for the current page. So, if $DefaultPasswords['read'] is set in local/GroupA.php, then someone could use a page in another group to view the contents of pages in GroupA. For example, Main.WikiSandbox could contain:

(:include GroupA.SomePage:)

and because the GroupA.php file wasn't loaded (we're looking at Main.WikiSandbox --> local/Main.php), there's no read password set.

The same is true for page customization files.

Isn't that processing order strange? Why not load per page configuration last (that is after global configuration an per group configuration)?

Many times what we want to do is to enable a certain capability for a group of pages, but disable it on a specific page, as if it was never enabled. If the per-group config file is processed first, then it becomes very difficult/tedious for the per-page one to "undo" the effects of the per-group page. So, we load the per-page file before the per-group.

If a per-page customization wants the per-group customizations to be performed first, it can use the techniques given above (using include_once() or setting $EnablePGCust = 0;).

How do I change the Wiki's default name in the upper left corner of the Main Page?

Put the following config.php

The docs/sample-config.php file has an example of changing the title.

How can I embed PmWiki pages inside a web page?

Source them through a PHP page, or place them in a frame.

How do I change the font or background color of the hints block on the Edit Page?

Add a CSS style to pub/css/local.css: .quickref {background:...; color:... }. The hints are provided by the Site.EditQuickReference page, which is in the PmWiki or Site wikigroup. Edit that page, and change the "bgcolor" or specify the font "color" to get the contrast you need.

How do I customize the CSS styling of my PmWiki layout?

See Skins for how to change the default PmWiki skin. See also Skins?, where you will find pre-made templates you can use to customize the appearance of your site. You can also create a file called local.css in the pub/css/ directory and add CSS selectors there (this file gets automatically loaded if it exists). Or, styles can be added directly into a local customization file by using something like:

Where can the mentioned "translation table" be found for adding translated phrases?

See Internationalizations.

Is it possible to have the edit form in full page width, with no sidebar?

If the sidebar is marked with <!--PageLeftFmt-->, adding (:noleft:) to Site.EditForm will hide it when a page is edited.

Can I easily hide the Home Page title from the homepage?

Yes, you can use in the wiki page either (:title Some other title:) to change it or (:notitle:) to hide it.

Is it possible to hide the Search-Bar in the default PmWiki Skin?

Yes, please see Cookbook:HideSearchBar.

How to track errors and know if they come from the PmWiki core or from a local configuration or addon/recipe?

The PHP programming language has recently deprecated or removed a number of functions that were heavily used in the past by PmWiki and many addons/recipes/skins. The PmWiki core no longer relies on these functions but some addons still do -- here is how to track these.

The PmWiki architecture allows addons (recipes, skins) and local configuration to register actions to be performed by PmWiki at a later point of the process. That's why the PHP warning may indicate a line in pmwiki.php, even if this was caused by a recipe.

It is recommended to get the latest versions of PmWiki and of all your addons -- known bugs would have been fixed. This assumes the errors are fixed in the latest versions.

(1) First disable or comment out all addons and local configuration (config.php, farmconfig.php, Group.php) and test your wiki. If the warning persists, please notify us ASAP with some information on how to reproduce the bug and on your installation (PHP version). If the error doesn't appear, go to (2).

(2) Enable one local configuration or one addon and test your wiki to see if the error appears.

(3) If the error doesn't appear, the problem is likely elsewhere. If you have more addons to enable, go back to (2).

(4) If the error appears, it was likely caused by the last configuration or addon that you enabled. Search the documentation and the cookbook for more recent versions, or contact the addon maintainer, or leave a message on the talk page. If that doesn't work, contact us at our issue tracking system. Developers can find documentation on how to update old addons at CustomMarkup and Functions.

(5) Disable again the faulty addon and if you have more addons to enable, go back to (2).

PmWiki has a friendly and reactive community and we may be able to quickly provide fixes.

After a PmWiki upgrade, there are warnings "Token invalid or missing" and the changes are not saved.

Some local customization may need to be updated, please see Upgrades#pmtoken.

After some upgrades to website, hosting, or browser, some skin styles/colors and possibly local styles, recipes, and embedded pictures, have stopped working.

In your local configuration, if you have the variables $PubDirUrl or $FarmPubDirUrl defined with the http:// scheme, replace them with https://. On secure websites, recent browser versions do not load resources from insecure URLs.

After a PHP upgrade, some of my markup rules have been disabled, and a tooltip title says (in English) "Markup rule ... is obsolete and has been disabled. See pmwiki.org/Troubleshooting".

The obsolete markup rule should appear on the tooltip title and should make it easy to identify which custom configuration or addon/recipe caused it. If it is not obvious, follow the steps in the first section. Developers can find documentation on how to update old addons at CustomMarkup and Functions.

My wiki displays warnings "Deprecated: Function create_function() is deprecated".

PHP version 7.2 deprecated a function which PmWiki used for markup definitions and pattern replacements. It is recommended to upgrade to the latest PmWiki version and update all addons and skins from the Cookbook?. Addons in the PHP 7.2 category are reported to be compatible with PHP 7.2. If you need a specific addon that has not yet been updated please contact us. To update your own addons, you probably need to update your calls to Markup(), see the pages Custom markup, Functions and PmWiki:CustomPagelistSortOrder.

The recipe Cookbook:PccfToPcfOverride may provide a temporary solution until you can update all your add-ons.

Note that PmWiki itself doesn't use that function, but (older) addons can register instructions to be processed at a later point. That's why the warning reports a line in pmwiki.php, even if it was requested by a local configuration or an addon.

How to track down the addons that cause the warnings, see the first section.

My wiki displays warnings "Deprecated: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead".

This is caused by a change in PHP version 5.5 for the preg_replace() function. PmWiki no longer relies on the deprecated feature since version 2.2.56 (it is recommended to upgrade to the latest version) but many recipes do.

Note that PmWiki itself doesn't use that function, but (older) addons can register instructions to be processed at a later point. That's why the warning reports a line in pmwiki.php, even if it was requested by a local configuration or an addon.

Recipes and Skins are currently being updated for PHP 5.5. Check if there are more recent versions published by their maintainers on the Cookbook. If you update your PmWiki and recipes, and still see the warnings, here is how to find out which recipes cause them:

For PmWiki version 2.2.71 or newer, in config.php, enable diagnostic tools:
$EnableDiag = 1;
Then visit your wiki with the action 'ruleset', for example PmWiki:PmWiki?action=ruleset or follow a link like [[HomePage?action=ruleset]]. This page will list all markup rules; those potentially incompatible with PHP 5.5 will be flagged with filenames, line numbers and search patterns triggering the warning.

If the ?action=ruleset page shows no flagged rules, it is possible that either your recipes call the preg_replace() function directly, or they define various search-replace patterns in incompatible ways. In these cases, your warning should display the file name and line number causing problems. Otherwise, to track down the addons that cause the warnings, see the first section.

Note that many hosting providers allow you to run different versions of PHP. See the documentation of your hosting plan to learn how to enable a PHP version earlier than 5.5.

Finally, it is possible to suppress these warnings in PHP 5.5, by setting this line at the beginning of config.php:
error_reporting(E_ALL & ~E_NOTICE & ~E_DEPRECATED);
This should be a temporary solution, left only until your recipes are fixed.

See categories:

My wiki displays warnings "PHP Deprecated: crypt(): Supplied salt is not valid for DES. Possible bug in provided salt format" or "Uncaught ArgumentCountError: crypt() expects exactly 2 arguments, 1 given".

You probably have configuration settings that worked on older PHP versions. Here is how to hunt and try to fix this.

In your (farm)config.php or other local or cookbook files, any call to crypt() can be replaced with pmcrypt(), eg
$DefaultPasswords['edit'] = crypt("my_password"); # DEPRECATED
$DefaultPasswords['edit'] = pmcrypt("my_password"); # OK
$DefaultPasswords['edit'] = array(pmcrypt("pass1"), pmcrypt("pass2")); # OK

Additionally, if there are locked passwords with a star *, you should replace those with @lock:
$DefaultPasswords['edit'] = '*'; # DEPRECATED
$DefaultPasswords['edit'] = '@lock'; # OK (and no pmcrypt)

The $DefaultPasswords variables usually have keys like 'edit', 'attr', 'read', 'upload', 'publish'.

Some of your page files may still have the old star * locking. Files that in the past shipped with the star lock were Site.GroupAttributes, SiteAdmin.GroupAttributes, Site.AuthUser and/or PmWiki.GroupAttributes in the directories wikilib.d and/or wiki.d. You need to edit them in a text editor and replace any line among these:
passwdedit=*
passwdattr=*
passwdread=*
passwdpublish=*
passwdupload=*

Edit the file and replace the star * with the word @lock on every existing line. Do not add these lines if they are not already in the file, and do not change the lines if there is something other than a single star after the = equals sign. Save the file, upload it back to your wiki and the warnings should disappear. (If you run a wiki farm, you may have such files in several wiki.d directories.)

My wiki displays warnings "Compilation failed: invalid range in character class".

A character class range in a regular expression is something in brackets like [A-Z]. An invalid character class may look like [Z-A], where the "Z" character should not be before but after the "A" character. It may not be that obvious, but it would be in brackets with a dash between the wrong characters.

If you want to match an actual dash (minus) rather than identify a character range, you need to place it first or last thing, like:
[-AZ] or [AZ-]

To track the error, see the first question on this page, and check the variables $GroupPattern, $NamePattern, $MakePageNamePatterns, $ROSPatterns and other locally configured core variables that contain "Pattern" or "Patterns" in the name.

After a PHP upgrade, some of the pages on my wiki are completely blank, empty, some have blank or missing sections, but the sidebar and the action links are visible.

Sometimes this may be caused by insufficient file permissions on the server. The PHP process needs "read/write (rw)" access to all files in the directories "wiki.d" and "uploads"; "read (r)" access to those in the "wikilib.d" directory; "list/search (x)" for the directories themselves. Search the documentation of your hosting provider for more information.

Alternatively, this may be caused by a change in PHP 5.4 which affects the function htmlspecialchars().

The easiest temporary fix would be in your php.ini, or in .user.ini to change the default_charset directive to an 8-bit charset, for example cp1252:
default_charset = "Windows-1252";

Or, this may sometimes work in local/config.php:
ini_set("default_charset", "Windows-1252");

A more permanent fix would be to upgrade your installation to a more recent PmWiki version, your recipes, and in your own recipes or modules replace all calls to htmlspecialchars() with PHSC(), a PmWiki helper function for such cases.

The "blank" pages come from the fact that in PHP 5.4 the default encoding switched from an 8-bit encoding to variable-bit validated UTF-8, and that an incorrect UTF-8 string will be rejected. If your wiki uses an 8-bit encoding, it is virtually certain that it is not valid UTF-8. Worse, even if you do use UTF-8 some browsers may submit invalid bits. So the PHSC() function always pretends that it converts an 8-bit encoding where all bits are allowed.

Very long pages with thousands of lines may appear blank after adding a few additional lines. This may be preformatted text, table, or text inside conditional markup, or text in a custom markup directive.

This may be caused by the PHP limits on how far to look forward, and loop back, when searching for matches of regular expressions. You may want to split the very long page into several pages, or the very long markup into separate sections/blocks, or you can increase the PHP limits by adding this to local/config.php:
@ini_set('pcre.backtrack_limit', 10000000);

Why am I seeing strange errors after upgrading?

Make sure all of the files were updated, in particular pmwiki.php and all files in the scripts/ directory.

This question sometimes arises when an administrator hasn't followed the advice, which used to be less prominent, on the installation and initial setup tasks pages and has renamed pmwiki.php instead of creating an index.php wrapper script. If you have renamed pmwiki.php to index.php, then the upgrade procedure won't have updated your index.php file. Delete the old version and create a wrapper script so it won't happen again.

Sometimes an FTP or other copy program will fail to transfer all of the files properly. One way to check for this is by comparing file sizes.

Be sure all of the files in the wikilib.d/ directory were also upgraded. Sometimes it's a good idea to simply delete the wikilib.d/ directory before upgrading. (Local copies of pages are stored in wiki.d/ and not wikilib.d/.)

Make sure that the file permissions are correct. The official files have a restricted set of permissions that might not match your site's needs.

If you use a custom pattern for $GroupPattern make sure that it includes Site ($SiteGroup) and since PMWiki 2.2 also SiteAdmin ($SiteAdminGroup). Otherwise migration may fail (e.g. missing SiteAdmin for PMWiki 2.2 and later) and/or login does not work.
Additionally Main ($DefaultGroup) should be included too.

I'm suddenly getting messages like "Warning: fopen(wiki.d/.flock): failed to open stream: Permission denied..." and "Cannot acquire lockfile"... what's wrong?

Something (or someone) has changed the permissions on the wiki.d/.flock file or the wiki.d/ directory such that the webserver is no longer able to write the lockfile. The normal solution is to simply delete the .flock file from the wiki.d/ directory -- PmWiki will then create a new one. Also be sure to check the permissions on the wiki.d/ directory itself. (One can easily check and modify permissions of the wiki.d/ directory in FileZilla (open-source FTP app) by right-clicking on the file > File attributes)

My links in the sidebar seem to be pointing to non-existent pages, even though I know I created the pages. Where are the pages?

Links in the SideBar normally need to be qualified by a WikiGroup in order to work properly (use [[Group/Page]] instead of [[Page]]).
Also: Make sure you type SideBar with a capital B.

Why am I seeing "PHP Warning: Cannot modify header information - headers already sent by ..." messages at the top of my page.

If this is the first or only error message you're seeing, it's usually an indication that there are blank lines, spaces, or other characters before the <?php or after the ?> in a local customization files such as config.php. Double-check the file and make sure there is nothing before the initial <?php. It's often easiest and safest to eliminate any closing ?> altogether.

When you save the file, the encoding/charset should be either cp1252/Windows1252 or UTF-8 without Byte Order Mark. NotePad++ is an editor that can do this.

When you transfer the files, tell your FTP manager to use text mode transfer, or, if that doesn't help, binary mode transfer.

If the warning is appearing after some other warning or error message, then resolve the other error and this warning may go away.

How do I make a PHP Warning about function.session-write-close go away?

If you are seeing an error similar to this

Warning: session_write_close() [function.session-write-close]:
open(/some/filesystem/path/to/a/directory/sess_[...]) failed: No such file
or directory (2) in /your/filesystem/path/to/pmwiki.php on line NNN

PmWiki sometimes does session-tracking using PHP's session-handling functions. For session-tracking to work, some information needs to be written in a directory on the server. That directory needs to exist and be writable by the webserver software. For this example, the webserver software is configured to write sessions in this directory

but the directory doesn't exist. The solution is to do at least one of these:

• Create the directory and make sure it's writable by the webserver software
• Provide a session_save_path value that points to a directory that is writable by the server, e.g. in config.php:

Why is PmWiki prompting me multiple times for a password I've already entered?

This could happen like out of nowhere if your hosting provider upgrades to PHP version 5.3, and you run an older PmWiki release. Recent PmWiki releases fix this problem.

Alternatively, this may be an indication that the browser isn't accepting cookies, or that PHP's session handling functions on the server aren't properly configured. If the browser is accepting cookies, then try setting $EnableDiag=1; in local/config.php, run PmWiki using ?action=phpinfo, and verify that sessions are enabled and that the session.save_path has a reasonable value. Note that several versions of PHP under Windows require that a session_save_path be explicitly set (this can be done in the local/config.php file). You might also try setting session.auto_start to 1 in your php.ini.

See also the question I have to log in twice below.

I edited config.php, but when I look at my wiki pages, all I see is "Parse error: parse error, unexpected T_VARIABLE in somefile on line number."

You've made a mistake in writing the PHP that goes into the config.php file. The most common mistake that causes the T_VARIABLE error is forgetting the semi-colon (;) at the end of a line that you added. The line number and file named are where you should look for the mistake.

Searches and pagelists stopped working after I upgraded -- no errors are reported, but links to other pages do not appear (or do not appear as they should) -- what gives?

Be sure all of the files in the wikilib.d/ directory were also upgraded. In particular, it sounds as if the Site.PageListTemplates page is either missing (if no links are displayed) or is an old version (if the links do not appear as they should). Also make sure that read-permissions (attr) are set for the pages Site.PageListTemplates and Site.Search.

Some of my posts are coming back with "403 Forbidden", "406 Not Acceptable", or "418 I'm a teapot" errors, or "Internal Server Error". This happens with some posts but not others.

Your webserver probably has mod_security enabled. The mod_security "feature" scans all incoming posts for forbidden words or phrases that might indicate someone is trying to hack the system, and if any of them are present then Apache returns the 403 Forbidden or 406 Not Acceptable error. Common phrases that tend to trigger mod_security include "curl ", "wget", "file(", and "system(", although there are many others (depending on the configuration, percent signs, html tags, international characters).

Since mod_security intercepts the requests and sends the "forbidden" message before PmWiki ever gets a chance to run, it's not a bug in PmWiki, and there's little that PmWiki can do about it. Instead, one has to alter the webserver configuration to disable mod_security or reconfigure it to allow whatever word it is forbidding. Some sites may be able to disable mod_security by placing SecFilterEngine off in a .htaccess file.

Alternatively, you may try the recipe Cookbook:EncodePost.

I get the following message when attempting to upload an image, what do I do?

Warning: move_uploaded_file(): SAFE MODE Restriction in effect. The script whose uid is 1929 is not allowed to access /home/onscolre/public_html/pmwikiuploads/Photos owned by uid 33 in /home/onscolre/public_html/pmwiki/scripts/upload.php on line 198

PmWiki can't process your request

?cannot move uploaded file to /home/onscolre/public_html/pmwikiuploads/Photos/FoundationPupilsIn1958.jpeg

We are sorry for any inconvenience.

Your server is configured with PHP Safe Mode enabled (removed as of PHP 5.4.0). Configure your wiki to use a site-wide uploads prefix, then create the uploads/ directory manually and set 777 permissions on it (rather than letting PmWiki create the directory).

I'm starting to see "Division by zero error in pmwiki.php..." on my site. What's wrong?

It's a bug in PmWiki that occurs only with the tables markup and only for versions of PHP >= 4.4.6 or >= 5.2.0. Often it seems to occur "out of nowhere" because the server administrator has upgraded PHP. Try upgrading to a later version of PmWiki to remove the error, or try setting the following in local/config.php:

    $TableRowIndexMax = 1;

I have to log in twice (two times) (2 times). -or- My password is not being required even though it should. -or- I changed the password but the old password is still active. -or- My config.php password is not over-riding my farmconfig.php password.

It could happen if (farm)config.php, or an included recipe, directly calls the functions CondAuth(), or RetrieveAuthPage(), PageTextVar(), PageVar() and possibly others, before defining all passwords and before including AuthUser (if required).

The order of config.php is very significant.

When editing an existing page, The "Save" causes a no-response of your server (not a blank page, no response at all, an endless connexion try). To get back the hand, it is necessary to request for another page (by clicking on its link in the menu for instance). And horror!, the ...?action=edit is then inhibited, it becomes impossible to edit any page.

When the editing of a page is initiated a file names .flock is created in the wiki.d repository. As long as this file exists it is impossible to edit any page. This file denotes an edition in progress and is automatically destroyed when leaving successfully an edit action by "Save". In case of a crash of the editing, this file is not destroyed. The remedy is, with an FTP client parameterized to show hidden files, to remove the .flock file. And all get back OK. This behavior is typically caused by a bug which provokes (directly or indirectly), an endless loop in a recipe concerned by the edited page.

I get the error "Data Mismatch - Locking FAILED!"

This is probably not a PmWiki error. PmWiki cannot create a lock file due to an underlying file system problem. For example the disk quota has been exceeded (e.g. by an error log file or file uploads), or there are problems with file system permissions.

Can I specify authorization group memberships from with local/config.php?

Yes -- put the group definition into the $AuthUser array (in config.php):

Can I have multiple admin groups?

Yes, define the groups with array('@admins', '@moderators'); like this:

$DefaultPasswords['admin'] = array( pmcrypt('masterpass'), # global password
    '@admins', '@moderators', # +users in these groups
    'id:Fred', 'id:Barney');  # +users Fred and Barney

I'm running multiple wikis under the same domain name, and logins from one wiki are appearing on other wikis. Shouldn't they be independent?

This is caused by the way that PHP treats sessions. See PmWiki.AuthUser#sessions for more details.

Is there any way to record the time of the last login for each user when using AuthUser? I need a way to look for stale accounts.

See Cookbook:UserLastAction.

Though every setting seems correct, authentication against LDAP is not working. There is nothing in ldap log, what's wrong?

Be sure ldap php module is installed ( on debian apt-get install php(4|5)-ldap ; apache(2)ctl graceful )

The login form asks for username and password, but only password matters.

Make sure you are not entering the admin password when testing the account because, if the password is equal to the admin password, it will authenticate directly through the config.php file and skip any other system.

Do note that even with AuthUser activated you can still log in with a blank username and only entering the password. In that case any password you enter will be "accepted" but only passwords which authenticate in the given context will actually give you any authorization rights. Using this capability AuthUser comfortably coexists with the default password-based system.

If you want to require both username and password, then you need to set an admin id before including authuser.php:

## Define usernames and passwords.
$AuthUser['carol'] = '$1$CknC8zAs$dC8z2vu3UvnIXMfOcGDON0';

## Enable authentication based on username.
include_once('scripts/authuser.php');

# $DefaultPasswords['admin'] = pmcrypt('secret');
$DefaultPasswords['admin'] = 'id:carol';

A username and password will then be required before login is successful.

Is there any way to hide IP addresses once someone has logged in so that registered users can keep their IP addresses invisible to everyone except administrators? - X 1/18/07

Yes, see solution provided at PITS:00400.

Is there a way that people could self-register through AuthUser?

You can see HtpasswdForm or UserAdmin for recipes providing this feature.

I would like it that after I have AuthUser turned and a user is authenticated to get on my site, that if I have a password put on a particular page or group that they don't get the AuthUser form to show up (username and password), but only the typical field for password?

See this thread of the mailing list (authuser vs passwords).

How to allow a group or a page for reading or editing, only to signed-in users?

You can set the password fields to id:*. Navigate to Group.Page?action=attr (for a single page) or to Group.GroupAttributes?action=attr (for the whole group) and fill the fields "New read password" and "New edit password" with id:* then save the form.

There seems to be a default password. What is it?

There isn't any valid password until you set one. Passwords admin describes how to set one.

PmWiki comes "out of the box" with $DefaultPasswords['admin'] set to '*'. This doesn't mean the password is an asterisk, it means that default admin password has to be something that encrypts to an asterisk. Since it's impossible for the pmcrypt() function to ever return a 1-character encrypted value, the admin password is effectively locked until the admin sets one in config.php.

How do I use passwd-formatted files (like .htpasswd) for authentication?

See AuthUser, Cookbook:HtpasswdForm or Cookbook:UserAuth2.

Is there anything I can enter in a GroupAttributes field to say 'same as the admin password'? If not, is there anything I can put into the config.php file to have the same effect?

Enter '@lock' in GroupAttributes?action=attr to require an admin password for that group.

How do I edit protect, say, all RecentChanges pages?

see Security#wikivandalism.

How can I read password protect all pages in a group except the HomePage using configuration files?

As described in PmWiki.GroupCustomizations per-group or per-page configuration files should not be used for defining passwords. The reason is that per-group (or per-page) customization files are only loaded for the current page. So, if $DefaultPasswords['read'] is set in local/GroupA.php, then someone could use a page in another group to view the contents of pages in GroupA. For example, Main.WikiSandbox could contain:

(:include GroupA.SomePage:)

and because the GroupA.php file wasn't loaded (we're looking at Main.WikiSandbox --> local/Main.php), there's no read password set.

How can I password protect the creation of new pages?

See Cookbook:LimitWikiGroups, Cookbook:NewGroupWarning, Cookbook:LimitNewPagesInWikiGroups.

How do I change the password prompt screen?

If your question is about how to make changes to that page... edit Site.AuthForm. If your question is about how to change which page you are sent to when prompted for a password, you might check out the Cookbook:CustomAuthForm for help.

How do I change the prompt on the attributes (?action=attr) screen?

Simply create a new page at Site.AttrForm?, and add the following line of code to config.php:

$PageAttrFmt = 'page:Site.AttrForm';

Note that this only changes the text above the password inputs on the attributes page, but doesn't change the inputs themselves - the inputs have to be dealt with separately. See Cookbook:CustomAttrForm for more info.

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.

I only want users to have to create an 'edit' password, which is automatically used for their 'upload' & 'attr' passwords (without them having to set those independently). How do I do this?

By setting $HandleAuth like so:

$HandleAuth['upload'] = 'edit';
// And to prevent a WikiSandbox from having it's 'attr' permissions changed 
// except by the admin (but allowing editors to change it on their own pages/group)
if(($group=="Site") || ($group=="Main") || ($group=="Category") || 
   ($group=="SiteAdmin") || ($group=="PmWiki") ) {
        $HandleAuth['attr'] = 'admin';  // for all main admin pages, set 'attr' to 'admin' password
} else { 
        $HandleAuth['attr'] = 'edit';  // if you can edit, then you can set attr
}

Why doesn't PmWiki use hierarchical / nested groups?

It essentially comes down to figuring out how to handle page links between nested groups; if someone can figure out an obvious, intuitive way for authors to do that, then nested groups become plausible. See Design Notes and PmWiki:Hierarchical Groups.

Why don't PmWiki's scripts have a closing ?> tag?

All of PmWiki's scripts now omit the closing ?> tag. The tag is not required, and it avoids problems with unnoticed spaces or blank lines at the end of the file. Also, some file transfer protocols may change the newline character(s) in the file, which can also cause problems. See also the Instruction separation page in the PHP manual.

Does PmWiki support WYSIWYG editing (or something like the FCKEditor)?

Short answer: PmWiki provides GUI buttons in a toolbar for common markups, but otherwise does not have WYSIWYG editing. For the reasons why, see PmWiki:WYSIWYG. See also Cookbook:Worse and Cookbook:PmSyntax.

Categories: PmWiki Developer