[ILUG] grep or awk

[Chris Higgins]

> there is no plan to upgrade anytime soon.

TCSH has an environment variable REMOTEHOST which is set to
identify the machine the connection is coming from (so that you
can set your DISPLAY environment variable for X easily).

You might prefer to use something like that, rather than
executing external apps to generate the info.

If you look at the solutions that have been found to the 
'I want to set my automatically X display to the host I've 
logged in from' - you might find a class of solutions that
suit (or more importantly, those situations where you can't
rely on the values you see in utmp)

Chris

> 
> the reason that i am looking to do this is that we have a lot of users
> who connect to an oracle database over telnet and print by going thru a
> menu of printers.
> 
> this list is getting crowded, (about 8 or so), so i want to provide
> different menus for the users depending on their ip address. ie
> 172.200.20.x = mis printers, 172.200.30.x = administration printers.
> 
> -----Original Message-----
> From: Chris Higgins [mailto:chris.higgins at horizon.ie]
> Sent: Monday, September 10, 2001 4:53 PM
> To: Irish Linux Users Group (E-mail)
> Subject: Re: [ILUG] grep or awk 
> 
> 
> We're talking about the contents of the wtmp/utmp files, as interpreted
> by
> the command 'who'
> 
> If you upgrade your version of who, and the formatting changes slightly,
> you run the risk of breaking your scripts (in strange and wonderful
> ways).
> 
> Would it not make more sense to query the files directly so that 
> you can be sure that the information is more reliable than grep'ing
> from 'who'
> 
> Chris (just my e0.02) - (see: man utmp)
> 
> > Fergal Daly wrote:
> > > sed 's/.*(\(.*\)).*\|.*/\1/'
> > > 
> > > will turn lines that don't have a matching pair of brackets into
> blanks,
> > > 
> > > > >     xxxxxxx     ttyqb       Sep 10 11:33
> > > > > (xxx.xxx.xxx.xxx)
> > 
> > I think 
> > sed -e 's/^[^(]*(\([^)]*\)).*$/\1/'
> > is slightly better, in that it will pick up the first matching pair of
> > brackets, rather than (on this line, say) printing (for example) "on
> > this line, say) printing (for example" rather than "on this line, say"
> -
> > but that's a matter of choice, if you're guaranteed that you'll only
> > have one pair of brackets.
> > 
> > Cheers,
> > Dave 
> > 
> > -- 
> > David Neary,               E-Mail dave.neary at palamon.ie
> > Palamon Technologies Ltd.  Phone +353-1-634-5059
> > 
> > -- 
> > Irish Linux Users' Group: ilug at linux.ie
> > http://www.linux.ie/mailman/listinfo/ilug for (un)subscription
> information.
> > List maintainer: listmaster at linux.ie
> 
> -- 
> ** Chris Higgins                         e: chris.higgins at horizon.ie
> **
> ** Technical Business Development        tel: +353-1-6204916
> **
> ** Horizon Technology Group              fax: +353-1-6204949
> **
> 
> 
> 
> -- 
> Irish Linux Users' Group: ilug at linux.ie
> http://www.linux.ie/mailman/listinfo/ilug for (un)subscription
> information.
> List maintainer: listmaster at linux.ie
> 
> -- 
> Irish Linux Users' Group: ilug at linux.ie
> http://www.linux.ie/mailman/listinfo/ilug for (un)subscription information.
> List maintainer: listmaster at linux.ie

-- 
** Chris Higgins                         e: chris.higgins at horizon.ie **
** Technical Business Development        tel: +353-1-6204916            **
** Horizon Technology Group              fax: +353-1-6204949            **