[[!meta robots="noindex, follow"]]
[[!if test="enabled(attachment)"
     then="This wiki has attachments **enabled**."
     else="This wiki has attachments **disabled**."]]

If attachments are enabled, the wiki admin can control what types of
attachments will be accepted, via the `allowed_attachments`
configuration setting.

For example, to limit arbitrary files to 50 kilobytes, but allow
larger mp3 files to be uploaded by joey into a specific directory, and
check all attachments for virii, something like this could be used:
  
	virusfree() and ((user(joey) and podcast/*.mp3 and mimetype(audio/mpeg) and maxsize(15mb)) or (!ispage() and maxsize(50kb)))

The regular [[ikiwiki/PageSpec]] syntax is expanded with thw following
additional tests:

* maxsize(size)

  Tests whether the attachment is no larger than the specified size.
  The size defaults to being in bytes, but "kb", "mb", "gb" etc can be
  used to specify the units.
  
* minsize(size)

  Tests whether the attachment is no smaller than the specified size.

* ispage()

  Tests whether the attachment will be treated by ikiwiki as a wiki page.
  (Ie, if it has an extension of ".mdwn", or of any other enabled page
  format).

  So, if you don't want to allow wiki pages to be uploaded as attachments,
  use `!ispage()` ; if you only want to allow wiki pages to be uploaded
  as attachments, use `ispage()`.

* user(username)

  Tests whether the attachment is being uploaded by a user with the
  specified username. If openid is enabled, an openid can also be put here.

* ip(address)

  Tests whether the attacment is being uploaded from the specified IP
  address.

* mimetype(foo/bar)

  This checks the MIME type of the attachment. You can include a glob
  in the type, for example `mimetype(image/*)`.

* virusfree()

  Checks the attachment with an antiviral program.