Why is Ferdora listening?

[Rick Stevens]

John Mahowald wrote:
> On Wed, 30 Mar 2005 20:31:19 +0200, Dotan Cohen <dotancohen at gmail.com> wrote:
> 
>>When I reset the computer this morning, I discovered this waiting for me:
>>
>>KWrited - listening on device /dev/pts/2
>>
>>(this is a translation of the hebrew message that I got, original message here):
>>KWrited - מקשיב בהתקן /dev/pts/2
>>
>>Is this something that should worry me? 
>>
> 
> 
> If you mean worry about network security, no. That  is a local device,
> for a virtual terminal I believe.

IIRC, kwrited is a kernel daemon that allows KDE desktop users to
receive messages sent via the "write" command from users on other
pseudoTTYs, serial ports, network logins, and X sessions.

/dev/pts/2 is a pseudoTTY.  Each time you run a terminal emulator on
your desktop or access it remotely (ssh, telnet, etc.), a pseudoTTY is
allocated to that session and your I/O is handled by it.  If, however,
you don't have a terminal emulator open on your desktop, you can't
receive any "write" messages since you don't have a pseudoTTY.

When KDE starts kwrited, it also grabs a pseudo TTY and uses it to
handle write requests (essentially, it opens a limited terminal
emulator), so when someone does "write fred", the write request will go
to the open /dev/pts/N device and Poof!  It shows up on Fred's X display
in a nice GUI window.

TECH STUFF: Actually, /dev/pts/N is the "slave" or "user" end of a
pseudoTTY while /dev/ptmx is the "master" or "server" end and is
implemented as a multiplexor.  If you want the gory details, see "man
pts(4)" (and yes, I've written LOTS of stuff using pseudoTTYs).

AFAIK, there's no equivalent to kwrited on Gnome, but you can probably
run kwrited under Gnome.  I've never done it, however.
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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-    Overweight:  When you step on your dog's tail...and it dies.    -
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