From owner-freebsd-questions  Sat Jan 22  7: 6:12 2000
Delivered-To: freebsd-questions@freebsd.org
Received: from dorifer.heim3.tu-clausthal.de (dorifer.heim3.tu-clausthal.de [139.174.243.252])
	by hub.freebsd.org (Postfix) with ESMTP id CF15B15546
	for <freebsd-questions@FreeBSD.ORG>; Sat, 22 Jan 2000 07:06:07 -0800 (PST)
	(envelope-from olli@dorifer.heim3.tu-clausthal.de)
Received: (from olli@localhost)
	by dorifer.heim3.tu-clausthal.de (8.9.3/8.9.3) id QAA14283;
	Sat, 22 Jan 2000 16:06:03 +0100 (CET)
	(envelope-from olli)
Date: Sat, 22 Jan 2000 16:06:03 +0100 (CET)
Message-Id: <200001221506.QAA14283@dorifer.heim3.tu-clausthal.de>
From: Oliver Fromme <olli@dorifer.heim3.tu-clausthal.de>
To: freebsd-questions@FreeBSD.ORG, cjclark@home.com
Reply-To: freebsd-questions@FreeBSD.ORG
Subject: Re: sh(1) Messing with My Mind
X-Newsgroups: list.freebsd-questions
In-Reply-To: <868r13$2gq9$1@atlantis.rz.tu-clausthal.de>
User-Agent: tin/1.4.1-19991201 ("Polish") (UNIX) (FreeBSD/3.4-19991219-STABLE (i386))
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
Sender: owner-freebsd-questions@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

Crist J. Clark <cjc@cc942873-a.ewndsr1.nj.home.com> wrote in list.freebsd-questions:
 > But since we're having so much fun with all of this, maybe I should
 > try this one on all of you. Given Ben's code above, how would _you_
 > determine how long ago $DATE was from the present time?

I'd first convert the date string to a time_t value.  The
easiest way to accomplish that is probably to install GNU
date:

   DATE="Fri 21 Jan 2000 00:15:59 GMT"
   TIMET=`gdate -d "$DATE" +%s`

$TIMET will then contain the number 948413759.  You can get
the current time (int time_t format) like this:

   NOW=`date +%s`

This works both with GNU date and BSD date (but BSD date
doesn't support something like the -d option of GNU date
above, AFAIK).

Now it is easy to make claculations and comparisons with the
time_t values, using "awk" or "expr" or whatever you like,
e.g.:

   ONE_DAY=86400      #   24 * 60 * 60
   YESTERDAY=`expr $NOW - $ONE_DAY`
   if [ $TIMET -lt $YESTERDAY ]; then
           echo "previous backup is older than one day"
           ...
   fi

You get the idea.  :)

Regards
   Oliver

-- 
Oliver Fromme, Leibnizstr. 18/61, 38678 Clausthal, Germany
(Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de)

"In jedem Stück Kohle wartet ein Diamant auf seine Geburt"
                                         (Terry Pratchett)


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message