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.

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.

Why are separate lines of text in the markup combined into a single line on output?

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 separate lines of markup text 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.

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
me]]
*
[[mailto:myaddress@example.com?subject=Some
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

Is it possible to link an image on PmWiki without using a fully qualified URL?

Yes. For images that are attachments, the general format is Attach:Groupname./image.gif. To link to an image that is on the same server, use Path:/path/to/image.gif.

Can I attach a client image file on PmWiki?

Yes, see Uploads .

How can I include a page from another group that contains an attached image?

Include the page in the normal way, ie (:include GroupName.Pagename:). In the page to be included (that contains the image) change Attach:filename.ext to Attach:{$Group}./filename.ext.

Why, if I put an image with rframe or rfloat and immediatly after that I open a new page section with ! the section title row is below the image instead of on the left side?

Because the CSS for headings such as ! contains an element clear:both which forces this behaviour. Redefine the CSS locally if you want to stop this happening, but I think the bottom border (that underlines the heading) would need further re-definition. I just use bolding for the title, and 4 dashes below ---- to separate a new section, and it saves the effort of fiddling with the core definitions.

Unlike the lframe and rframe directives, cframe does not fully honour the width setting. While the frame itself resizes to match the request, the enclosed image does not, and retains its original width. Effect is the same in IE and Fx. I've added an example beneath the standard example above.

Is it possible to disallow all images? I already disabled uploads but I also want to disallow external images from being shown on my wiki pages.

DisableMarkup('img');
$ImgExtPattern = "$^";

How can I make it so that when I place an image in a page, the block of text it is in is a <p> (paragraph) rather than a <div> (division)?

If you just want it to happen for a single image (instead of all), then try putting [==] at the beginning of the line, as in:

Having [==] at the beginning of a line forces whatever follows to be part of a paragraph.

Is there any way to use relative paths for images?

See Cookbook:RelativeLinks and $EnableLinkPageRelative.

Is there a way to attach a BMP and have it display rather than link?

Add to config.php the following line:
$ImgExtPattern = "\\.(?:gif|jpg|jpeg|png|bmp|GIF|JPG|JPEG|PNG|BMP)";
Note that BMP images are uncompressed and quite heavy. You may wish to convert them to PNG (lossless) or JPG (lossy) format, and thus reduce 5-20 times their filesizes.

Is there a way to have a table to the left or right of an image?

Yes, see TableAndImage.

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" bordercolordark="black"
bordercolorlight="black"
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 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.

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}:)?

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

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.

As of version 2.2.0, the last title in the page overrides previous ones. In future versions, this may be configurable, but for the moment, best is to place your (:title :) directive at the bottom of the page, after any includes.

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 can I get rid of the 'Main' group in urls for pages pointing to Main?

See Cookbook:Get Rid Of Main.

How can I limit the creation of new groups?

See Cookbook:Limit Wiki Groups.

Why doesn't [[St. Giles and St. James]] work as a link? (It doesn't display anything.)

Because it contains periods, and destroys PmWiki's file structure, which saves pages as Group.PageName. Adding those periods disrupts this format. Links may only contain words. If you need a link precisely as shown, the page must be named eg StGilesAndStJames then you can use the (:title:) directive to have the page's title appear with periods (:title St. Giles and St. James:). (Although modern US and UK grammar now tend to drop the period to simplify style).

How can I delete a wiki group?

Normally you can't, as this requires an admin with server-side access to delete the file that makes up the group's RecentChanges page. But there is an option method of making it possible to delete RecentChanges pages from within the wiki if the admin enables the code found on Cookbook:RecentChanges Deletion.

How can I delete a wiki group's Group.RecentChanges page?

Normally you can't, as this requires an admin with server-side access to delete a file. But there is an optional method of making it possible to delete RecentChanges pages from within the wiki if the admin enables the code found on Cookbook:RecentChanges Deletion.

How do I set one header for all pages/groups?

The header for each page is controlled by the $GroupHeaderFmt variable. Thus a site-wide groupheader can be added with

$GroupHeaderFmt = '(:include {$SiteGroup}.SiteHeader
                   basepage={*$FullName}:)(:nl:)' . $GroupHeaderFmt;

Note that single quotes must be used so that $Group (which is part of the default contents of $GroupHeaderFmt) will be substituted properly by PmWiki, and that this applies to all variables ending in $...Fmt. See also the Cookbook:AllGroupHeader page.

Any form of markup is valid in $GroupHeaderFmt, thus one can do

Would this then work for site footers?

$GroupFooterFmt = '(:include {$SiteGroup}.SiteFooter
                   basepage={*$FullName}:)(:nl:)' . $GroupFooterFmt;

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.

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

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 :

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?

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.

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:

    session_name('XYZSESSID');

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

    session_name('CS559SESSID');

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

Deleting Wiki Groups & Categories: Once I create a Group or Category, how can I get rid of that group or category?

An admin can just remove the unwanted pages from wiki.d/ . Normally, doing it via the wiki doesn't resolve the problem, since it counts as an "update" which causes the Recent Changes? page to be re-created, but it is possible to modify the site's configuration to allow deletion of the group's RecentChanges page -- see Cookbook:RecentChangesDeletion.

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

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).

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.

Is it possible to move wiki.d to /tmp/persistent/foo/wiki.d (a new sourceforge rule)?

Sourceforge suggests moving everything to /tmp/persistent/new-folder-of-your-choice/ and creating a symbolic link to the new folder on /tmp . It works -- see Cookbook:SourceForgeServers.

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

See Cookbook:Standalone or Cookbook:WikiOnAStick.

How can I determine what version of PmWiki I'm running now?

See version - Determining and displaying the current version of PmWiki (pmwiki-2.2.15).

How can I test a new version of PmWiki on my wiki without changing the prior version used by visitors?

The easy way to do this is to install the new version in a separate directory, and for the new version set (in local/config.php):

    $WikiLibDirs = array(&$WikiDir,
      new PageStore('/path/to/existing/wiki.d/{$FullName}'),
      new PageStore('wikilib.d/{$FullName}'));

This lets you test the new version using existing page content without impacting the existing site or risking modification of the pages. (Of course, any recipes or local customizations have to be installed in the new version as well.)

Then, once you're comfortable that the new version seems to work as well as the old, it's safe to upgrade the old version (and one knows of any configuration or page changes that need to be made).

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).

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 (:attachlist:) markup.

How can I find orphaned or missing attachments

See Cookbook:Attachlist enhanced

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 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

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 all common pages in all groups such as recent changes, search, group header, group footer, and so on?

Insert the following lines into your local/config.php file. Editing these pages then requires the admin password.

## Require admin password to edit RecentChanges (etc.) pages.
if ($action=='edit'
    && preg_match('/\\.(Search|Group(Header|Footer)|(All)?RecentChanges)$/', $pagename))
  { $DefaultPasswords['edit'] = crypt('secret phrase'); }

Note that all GroupAttributes pages are protected by the attr password.

Alternative: you can require 'admin' authentication for these pages:

## Require admin password to edit RecentChanges (etc.) pages.
if ($action=='edit' 
    && preg_match('(Search|Group(Header|Footer)|(All)?RecentChanges)', $pagename))
  { $HandleAuth['edit'] = 'admin'; }

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

or

How to make a rule that allows only authors to edit their own wiki page in Profiles? group?

Add this to your local/config.php

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 $EnablePublish, 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
• see Cookbook:Secure attachments

Are InterMap names case sensitive?

Yes, thus eAdmin: is a different InterMap link than EAdmin:.

How can I achieve a localmap.txt mapping with the effect of Pics: Path:/somepathto/pics/?

Use the following:

How can I define an InterMap in PHP?

Use the following:

      $LinkFunctions['PmWikiHome:'] = 'LinkIMap';
      $IMap['PmWikiHome:'] = 'http://pmwiki.org/wiki/$1';

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 <script> statements can be inserted using the $HTMLHeaderFmt array.

How would I create a markup ((:nodiscussion:)) that will set a page variable ({$HideDiscussion}) which can be used by (:if enabled HideDiscussion:) in .PageActions?

Add the following section of code to your config.php

SDV($HideDiscussion, 0); 	#define var name
Markup('hideDiscussion', '<{$var}',
 '/\\(:nodiscussion:\\)/e', 'setHideDiscussion(true)'); 
function setHideDiscussion($val) { 
  global $HideDiscussion; 
  $HideDiscussion = $val;
} 

This will enable the (:if enabled HideDiscussion:) markup to be used. If you want to print the current value of {$HideDiscussion} (for testing purposes) on the page, you'll also need to add the line:
$FmtPV['$HideDiscussion'] = '$GLOBALS["HideDiscussion"]';

PmWiki only supports tool tips for external links, can I use custom markup to add tool tips to internal links?

Yes, add the following custom markup to your config.php:
Markup('%title%', 'inline', '/%title%(.*?)"(.*?)"(.*?)%%/', '<span title="$2">$1$3</span>'); # Add tool tips to internal links, Example: %title%[[link"tool tip"]]%%

Use the markup with internal links such as:
%title%[[CookBook "cool" | Example]]%%

See also Cookbook:LinkTitles.

It appears that (.*?) does not match newlines in these functions, making the above example inoperable if the text to be wrappen in <em> contains new lines.

If you include the "s" modifier on the regular expression then the dot (.) will match newlines. Thus your regular expression will be "/STUFF(.*?)/s". That s at the very end is what you are looking for. If you start getting into multi-line regexes you may be forced to look at the m option as well - let's anchors (^ and $) match not begin/end of strings but also begin/end of lines (i.e., right before/after a newline).

How do I get started writing recipes and creating my own custom markup?

(alternate) Introduction to custom markup for Beginners

If my wiki is internationalized by config.php, how do I revert a specific group to English?

Use $XLLangs = array('en'); in the group's group customization file.

If my wiki is in English and I want just one page, or group, in Spanish do I say XLPage('es','PmWikiEs.XLPage'); in the group or page configuration file?

Yes, that is usually the best method. If you were doing this with many scattered pages, or with several languages, you might find it easier to maintain if you load the translations all in config.php like this:

   XLPage('es','PmWikiEs.XLPage');
   XLPage('fr','PmWikiFr.XLPage');
   XLPage('ru','PmWikiRu.XLPage');
   $XLLangs = array('en');

Then in each group or page configuration file, you'd just use $XLLangs = array('es'); to set the language to use (in this case, Spanish). Note that though this method is easier to maintain, its somewhat slower because it loads all the dictionaries for each page view, even if they won't be used.

What does the first parameter of this function stand for? How can it be used?

The XLPage mechanism allows multiple sets of translations to be loaded, and the first parameter is used to distinguish them.

For example, suppose I want to have translations for both normal French and "Canadian" French. Rather than maintain two entirely separate sets of pages, I could do:

    XLPage('fr', 'PmWikiFr.XLPage');
    XLPage('fr-ca', 'PmWikiFrCa.XLPage');

PmWikiFr.XLPage would contain all of the standard French translations, while PmWikiFrCA.XLPage would only need to contain "Canada-specific" translations -- i.e., those that are different from the ones in the French page.

The first parameter distinguishes the two sets of translations. In addition, a config.php script can use the $XLLangs variable to adjust the order of translation, so if there was a group or page where I only wanted the standard French translation, I can set

    $XLLangs = array('fr', 'en');

and PmWiki will use only the 'fr' and 'en' translations (in that order), no matter how many translations have been loaded with XLPage().

Tools for PmWiki Localization

You can help to localize PmWiki in your language in the original site:

• Localization
• Translation Portal

There's no "config.php"; it's not even clear what a "local customisation file" is!

The "sample-config.php" file in the "docs" folder, is given as an example. Copy it to the "local" folder and rename it to "config.php". You can then remove the "#" symbols or add other commands shown in the documentation. See also Group Customizations.

Can I change the default page something other than Main.HomePage ($DefaultPage)?

Yes, just set the $DefaultPage variable to the name of the page you want to be the default. You might also look at the $DefaultGroup and $DefaultName configuration variables.

How do I get the group / page name in a local configuration file (e.g. local/config.php)?

Use the following markup in pmwiki-2.1.beta21 or newer:

## Get the group and page name
$pagename = ResolvePageName($pagename);
$page = PageVar($pagename, '$FullName');
$group = PageVar($pagename, '$Group');
$name = PageVar($pagename, '$Name');

Can I remove items from the wikilib.d folder on my site?

Yes, the files in wikilib.d/ can be safely removed. They'll reappear again when you upgrade, however.

How do I customize my own 404 error page for non-existent pages?

To change the text of the message, try editing the Site.PageNotFound page.

Is the order of customizations in config.php important? Are there certain things that should come before or after others in that file? ^[1]

Yes, the following has been recommended on the mailing list:

• define $ScriptUrl and $PubDirUrl, if needed,
• define any custom PageStore class, like SQLite, CompressedPageStore or PerGroupSubDirectories,
• next include_once scripts/xlpage-utf-8.php,
• next call XLPage() which needs the definitive (rw) $WikiDir already set in order to find the wiki page containing the translations,
• next include authuser.php (if needed), because PmWiki caches some group and page authorization levels when a page is accessed,
• next include any other scripts and recipes,
• any direct function call in config.php, like ResolvePageName(), CondAuth(), PageTextVar(), PageVar(), RetrieveAuthPage(), or others, if possible, should be done near the end of config.php.

Note, each part is not required, but if your wiki needs it, this is the recommended order in config.php.

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.

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

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 in PmWiki.GroupCustomizations (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 Cookbook: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 do I include text from the page (whole page, or first X characters) in the feed body? (note: markup NOT digested)

    function MarkupExcerpt($pagename) {
      $page = RetrieveAuthPage($pagename, 'read', false);
      return substr(@$page['text'], 0, 200);
    }

    $FmtPV['$MarkupExcerpt'] = 'MarkupExcerpt($pn)';
    $FeedFmt['rss']['item']['description'] = '$MarkupExcerpt';

Q:Does this mean if I want to include the time in the rss title and "summary" to rss body I call $FeedFmt twice like so:

$FeedFmt['rss']['item']['description'] = '$LastSummary'; 
$FeedFmt['rss']['item']['title'] = '{$Group} / {$Title} @ $ItemISOTime';

How can I use the RSS <enclosure> tag for podcasting?

For podcasting of mp3 files, simply attach an mp3 file to the page with the same name as the page (i.e., for a page named Podcast.Episode4, one would attach to that page a file named "Episode4.mp3"). The file is automatically picked up by ?action=rss and used as an enclosure.

The set of potential enclosures is given by the $RSSEnclosureFmt array, thus

allows podcasting in mp3, wma, and ogg formats.

How to add "summary" to the title in a rss feed (ie. with ?action=rss)?

Add this line in you local/config.php

How to add "description" to the title in an rss feed, and summary to the body?

Add these lines to your local/config.php

NOTES:

• you need to replicate these lines for each type (atom, rdf, dc) of feed you provide.
• the RSS description-tag is not equivalent to the pmWiki $Description variable, despite the confusing similarity.

Some of my password-protected pages aren't appearing in the feed... how do I work around this?

From a similar question on the newsgroup, Pm's reply:

The last time I checked, RSS and other syndication protocols didn't really have a well-established interface or mechanism for performing access control (i.e., authentication). As far as I know this is still the case.

PmWiki's WebFeeds capability is built on top of pagelists, so it could simply be that the $EnablePageListProtect option is preventing the updated pages from appearing in the feed. You might try setting $EnablePageListProtect=0; and see if the password-protected pages start appearing in the RSS feed.

The "downside" to setting $EnablePageListProtect to zero is that anyone doing a search on your site will see the existence of the pages in the locked section. They won't be able to read any of them, but they'll know they are there!

You could also set $EnablePageListProtect to zero only if ?action=rss:

    if ($action == 'rss') $EnablePageListProtect = 0;

This limits the ability to see the protected pages to RSS feeds; normal pagelists and searches wouldn't see them.

Lastly, it's also possible to configure the webfeeds to obtain the authentication information from the url directly, as in:

    .../Site/AllRecentChanges?action=rss&authpw=secret

The big downside to this is that the cleartext password will end up traveling across the net with every RSS request, and may end up being recorded in Apache's access logs.

How to add feed image?

Add the following to local/config.php (this example is for ?action=rss):

$FeedFmt['rss']['feed']['image'] =
" <title>Logo title</title>
 <link>http://example.com/</link>
 <url>http://example.com/images/logo.gif</url>
 <width>120</width>
 <height>60</height>";

How do I insert RSS news feeds into PmWiki pages?

See Cookbook:RssFeedDisplay.

How can I specify default feed options in a configuration file instead of always placing them in the url?

For example, if you want ?action=rss to default to ?action=rss&group=News&order=-time&count=10, try the following in a local customization file:

   if ($action == 'rss')
     SDVA($_REQUEST, array(
       'group' => 'News',
       'order' => '-time',
       'count' => 10));

Are there ways to let people easily subscribe to a feed?

$HTMLHeaderFmt['feedlinks'] = '<link rel="alternate" type="application/rss+xml" 
  title="$WikiTitle" href="$ScriptUrl?n=Site.AllRecentChanges&amp;action=rss" />
<link rel="alternate" type="application/atom+xml" title="$WikiTitle"
  href="$ScriptUrl?n=Site.AllRecentChanges&amp;action=atom" />';

You can also add such a link, for example in your SideBar, [[Site.AllRecentChanges?action=atom | Subscribe to feed]].

Can I create an RSS feed for individual page histories?

See Cookbook:PageFeed.

How do I create a custom FeedPage similar to RecentChanges or AllRecentChanges, but with only certain groups or pages recorded?

See Cookbook:CustomRecentChanges. In a nutshell, you'll declare a $RecentChangesFmt variable with your dedicated FeedPage, and then wrap it in a condition of your choice. For example:

   if (PageVar($pagename, '$Group')!='ForbiddenGroup') {
     $RecentChangesFmt['Site.MyFeedPage'] =
       '* [[{$FullName}]]  . . . $CurrentTime $[by] $AuthorLink: [=$ChangeSummary=]';
   }

How can I update my RSS feed to show every edit for pages on that feed, not just new pages added to the feed?

Add unique guid links for each edit to your to congif.php file (see PITS entry):

   $FeedFmt['rss']['item']['guid'] = '{$PageUrl}?guid=$ItemISOTime';

Alternatively, you can create the option for edit monitoring by adding a qualifier for RSS links. This allows the user to choose between default new pages RSS feeds and new edits RSS feeds (pmwiki.org has this option enabled).

   ## For new pages updates: http://example.com/wiki/HomePage?action=rss
   ## For edits updates: http://example.com/wiki/HomePage?action=rss&edits=1
   if(@$_REQUEST['edits'] && $action == 'rss')
     $FeedFmt['rss']['item']['guid'] = '{$PageUrl}?guid=$ItemISOTime';

Why am I seeing strange errors after upgrading?

Make sure all of the files were updated, in particular pmwiki.php.

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/.)

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 "Warning: Cannot modify header information - headers already sent ..." 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 or spaces before the <?php or after the ?> in a local customization file. Double-check the file and make sure there aren't any blank lines or spaces before the initial <?php. It's often easiest and safest to eliminate any closing ?> altogether. On Windows, it may be necessary to use a hex editor to convert LFCR line endings to LF line endings in the local\config.php file.

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.

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

Usually this is 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.

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). Allso 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" errors, "Not Acceptable", 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 error. Common phrases that tend to trigger mod_security include "curl ", "wget", "file(", and "system(", although there are many others.

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.

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. 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.

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.

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

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

        $AuthUser['@editors'] = array('alice', 'carol', 'bob');

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 settings seem correct, authentication against LDAP is not working, and 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'] = crypt('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

Not yet.

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

You can see Cookbook:AuthUserSignup for a recipe about this problem.

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.

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 crypt() 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:UserAuth.

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.