ses: Virus protection
4.7 Virus protection
====================
Whenever a formula or printer is read from a file or is pasted into the
spreadsheet, it receives a “needs safety check” marking. Later, when
the formula or printer is evaluated for the first time, it is checked
for safety using the ‘unsafep’ predicate; if found to be “possibly
unsafe”, the questionable formula or printer is displayed and you must
press Y to approve it or N to use a substitute. The substitute always
signals an error.
Formulas or printers that you type in are checked immediately for
safety. If found to be possibly unsafe and you press N to disapprove,
the action is canceled and the old formula or printer will remain.
Besides viruses (which try to copy themselves to other files),
‘unsafep’ can also detect all other kinds of Trojan horses, such as
spreadsheets that delete files, send email, flood Web sites, alter your
Emacs settings, etc.
Generally, spreadsheet formulas and printers are simple things that
don’t need to do any fancy computing, so all potentially-dangerous parts
of the Emacs Lisp environment can be excluded without cramping your
style as a formula-writer. See the documentation in ‘unsafep.el’ for
more info on how Lisp forms are classified as safe or unsafe.
Info Catalog
ses: Import and export
ses: Advanced Features
ses: Spreadsheets with details and summary