how to insert random error in a programming

[Roy Smith]

In article 
<d391c7a4-41ab-4992-84cb-cacd1550d022 at a4g2000pbc.googlegroups.com>,
 rusi <rustompmody at gmail.com> wrote:

> On Oct 15, 9:00 pm, John Gordon <gor... at panix.com> wrote:
> > In <mailman.2205.1350309347.27098.python-l... at python.org> Debashish Saha 
> > <silid... at gmail.com> writes:
> >
> > > how to insert random error in a programming?
> >
> > Open the program source file and replace the Nth character with a random
> > character.
> 
> I'm reminded of a description of vi:
> 
> A program with two modes, one in which it beeps and the other in which
> it corrupts your file.

All the vi you need to know:  <esc> : q ! <return>