Quoting SRIDHARAN Aravind <[EMAIL PROTECTED]>:

> If 'Print' button could be disabled,
> why not 'Save' button?

> What is the technical issue behind this?

I thought it was in the mailing list archives,
but I didn't find it.

> Please let me know as I need to explain my higher officials here who asked
> this.
> I want some in-depth technical details I am in a very crucial stage to
> explain them.

The interpretation of a file is done by a tool: Acrobat
Reader, GhostView,...
These tools follow the PDF specs, so if the PDF specs
allow you to disable actions such as Printing, Copying parts
of the content, Annotate,... These tools will support this.

The transport of the file IS NOT DEPENDENT FROM THE SPECS.
It is not a PDF issue. A server provides a file (ANY FILE,
not just PDF) and it is sent to a client (a browser, a GET
in a telnet session, an application,...) using the HTTP
protocol.

So ANY user can retrieve the document from your server
in different ways and SAVE it. If the document is password
protected, the user may not be able to open it or read it,
but he will always be able to save it.

Most client applications DO SAVE the document EVEN IF
CACHING IS DISABLED. The PDF file is saved in the TEMP
directory.
Before a PDF file can be interpreted the CrossReference Table
has to be read. The CrossReference table tells the Viewer where
to find all the PDF objects (containing content, text, fonts,
images,...). It is always AT THE END of a PDF file (there are
exceptions, but I don't want to get to technical!).

So before the Viewer can show anything, it needs to read the
complete file (to read the X-Reference table at the end)
and then retrieve all the objects that are referenced in
the X-Reference table. A Viewer could keep the complete file
in memory to do this, but most Viewer store it on disk.

> Earnestly awaiting your reply.
> Please do not think that I trouble or disturb you anyway.
 
I sent a copy to the mailing list so other people can
comment on my answer. Paulo Soares and Leo Rosenthal
can give you a lot more details.

Bruno


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