---+ Package =TWiki::Sandbox=

This object provides an interface to the outside world. All calls to
system functions, or handling of file names, should be brokered by
this object.

NOTE: TWiki creates a singleton sandbox that is *shared* by all TWiki
runs under a single mod_perl instance. If any TWiki run modifies the
sandbox, that modification will carry over in to subsequent runs.
Be very, very careful!


%TOC%

---++ ClassMethod *new* <tt>($os,$realOS)</tt>

Construct a new sandbox suitable for $os, setting
flags for platform features that help.  $realOS distinguishes
Perl variants on platforms such as Windows.



---++ ObjectMethod *finish* <tt>()</tt>
Break circular references.



---++ StaticMethod *untaintUnchecked* <tt>($string) -> $untainted</tt>

Untaints $string without any checks (dangerous).  If $string is
undefined, return undef.

The intent is to use this routine to be able to find all untainting
places using grep.



---++ StaticMethod *normalizeFileName* <tt>($string) -> $filename</tt>

Errors out if $string contains filtered characters.

The returned string is not tainted, but it may contain shell
metacharacters and even control characters.



---++ StaticMethod *sanitizeAttachmentName* <tt>($fname) -> ($fileName,$origName)</tt>

Given a file name received in a query parameter, sanitise it. Returns
the sanitised name together with the basename before sanitisation.

Sanitisation includes filtering illegal characters and mapping client
file names to legal server names.



---++ ObjectMethod *sysCommand* <tt>($template,@params) -> ($data,$exit)</tt>

Invokes the program described by $template
and @params, and returns the output of the program and an exit code.
STDOUT is returned. STDERR is THROWN AWAY.

The caller has to ensure that the invoked program does not react in a
harmful way to the passed arguments.  sysCommand merely
ensures that the shell does not interpret any of the passed arguments.


