Re: write(1)

[jauderho () NETCOM COM (Jauder Ho)]

        to do the beep....

try \cG

print(JIM "\cG\nMessage from $ARGV[1]\@$host on $terminal at $time ...\n");


--Jauder (Perl is your friend!)

On Wed, 21 May 1997, test wrote:

> Program Effected: write(1)
> Impact: Mostly Harmless
>
>         It is trivial to spoof a write from one user to the next locally
>         on a system by faking an "EOF".  This ofcourse does not effect
>         users who have turned off their write permissions.  It's also
>         fairly noticeable by the lack of any beep.
>
>
> print(JIM "\nMessage from $ARGV[1]\@$host on $terminal at $time ...\n");
> foreach $line (@to_write){
>         sleep $delay;
>         print (JIM "$line\n");
>         }
> $| = 0;
> close(JIM);
> -------------------------------swrite----------------------------------------
>
>         example usage...
>
>         Un*x % echo The System is going down IMMIDIATELY\! | ./swrite \
>         user root console
>
>
>         If your an absolute paranoid, here are the diff's of an incomplete
>         patch for write.c.. it's a start anyhow.
>
> 281c281,284
> <       while (fgets(line, sizeof(line), stdin) != NULL)
> ---
> >       while (fgets(line, sizeof(line), stdin) != NULL){
> >               if(!strcmp(line, "EOF\n")){
> >                       (void)strcpy(line, "EOF <-- Warning: Not End of File.\n");
> >               }
> 282a286
> >       }
>
>
>         It'll work for "EOF" just not for "EOF " or "EOF  " etc...


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