What does the /dev/NULL file do?

[Paul Rybski]

Hi,
I was wondering what the purpose of the NULL file was and
whether it was extraordinarly manditory for anything. It seems to be
just a blank file that serves no real purpose... of course, I could just
be extraordinarily dense on this one. Can anyone shed some light on
this?

Thanks

-Paul E. Rybski
ryb...@edsi.plexus.com
--

[Trammell B. Hudson]

In article <1993Jul17....@edsi.plexus.COM>, ryb...@edsi.plexus.COM (Paul Rybski) writes:
|> I was wondering what the purpose of the NULL file was and
|> whether it was extraordinarly manditory for anything. It seems to be
|> just a blank file that serves no real purpose... of course, I could just
|> be extraordinarily dense on this one. Can anyone shed some light on
|> this?

/dev/null is a special device file, normally called the "bit bucket".
Anything you send into it is ignored. The main use is to redirect output to
it if you don't want to it or send stderr there for the equivilant of a -quiet
option on nasty programs that don't have one.

Direct all comments to this group or:
tbhu...@whale.st.usm.eduu lshu...@nsula.edu tramm_...@agwbbs.us
tr...@bourbon.ee.tulane.edu tr...@lsmsa.nsula.edu ro...@192.102.223.10

Direct all complaints to /dev/null at the site of your choice.

GCS/T/M/E d--- -p+ c+++ l+++ m++ s-/! !g++ w+++ t+ r x-

[Marcus J. Ranum]

> /dev/null is a special device file, normally called the "bit bucket".
>Anything you send into it is ignored. The main use is to redirect output to
>it if you don't want to it or send stderr there for the equivilant of a -quiet
>option on nasty programs that don't have one.

Most systems managers have a cron job that empties their null
device every so often.

I've been lucky. I bought one of the newer Cygnetix NullDevs
and now I don't have to empty it hardly at all. I think I last emptied
it 4 months ago, when there was that big flame-war in the OSI group
and my news software logged a lot of stuff to /dev/null and it almost
overflowed. Remember back in the old days of UNIX? Shoot, the PDP-11s
had those wimpy little 8-bit null devices that could only transfer
something like 50kb/sec. Nowadays with the newer IPI null devices
you can bitbucket data at almost bus speed.

mjr.
--
C++ -> C :: cancer -> lung