topic Re: Reg Previous date calculation in Operating System - HP-UX

Reg Previous date calculation

harikrishna — Tue, 02 Mar 2004 22:48:37 GMT

hi friends,
i am using the following command for calculating the previous date in hp unix server.

$(sh -c "TZ=$(date +%Z)+24; export TZ; date '+%Y%m%d'")

But it is not working now.i dont know why. so if any body plz let me know any command to calculate the prevoius date.it is very urgent to me.

Thanks in Advance

Regards,
HariKrishna

Re: Reg Previous date calculation

Sridhar Bhaskarla — Tue, 02 Mar 2004 22:55:15 GMT

Hi HariKrishna,

Try the following simple script

NOW=$(/usr/contrib/bin/perl -e "printf("%d\n",time())")
(( YES = $NOW - 86400 ))
echo "0d${YES}=Y" |adb

86400 is the number of seconds since yesterday. If you want 'n' days back, then you calculate it by doing n*24*60*60

-Sri

Re: Reg Previous date calculation

harikrishna — Tue, 02 Mar 2004 22:59:48 GMT

hi sri,
thanks for giving the reply.but i want the code in unix script only .

plz let me know if you know it in the unix

Thanking you

regards,
HariKrishna

Re: Reg Previous date calculation

Sridhar Bhaskarla — Tue, 02 Mar 2004 23:03:21 GMT

Hi Harikrishna,

That is unix script. Perl is available in /usr/contrib/bin on any HP-UX and it is used only once to get the epoch seconds. Rest are all HP commands.

-Sri

Re: Reg Previous date calculation

A. Clay Stephenson — Wed, 03 Mar 2004 12:23:23 GMT

Tricks that alter TZ only work over a limited range of TZ's because the offset must remain in the range 0-23. Scripts that violate this only work by accident and can break without warning (e.g. a patch to the date command of libC). Man 5 environ for details. The Perl solution is a valid one but here's a method that will work over any date range --- including those that will kill the Perl solution.

YESTERDAY=$(caljd.sh -s -y $(calhd.sh -p 1))
echo "Yesterday = ${YESTERDAY}"

If you like, you can yank out the cal_jdate and jdate_cal functions and use them inside your own script for a "pure" shell solution.

Re: Reg Previous date calculation

Dave La Mar — Wed, 03 Mar 2004 19:22:18 GMT

The following is used quite a bit here and differs only in the variable value read in.
TZ=PST8PDT+24 date +%A | read Yesterday

But for a robust and solid date routine, A.Clay's has been noted by many to be the top choice.

We also use his. Shucks, now I owe royalties.

Best of luck.

Regards,

dl

Re: Reg Previous date calculation

A. Clay Stephenson — Wed, 03 Mar 2004 19:30:37 GMT

Ooops, you'd think I could get my own command right, should be:

YESTERDAY=$(caljd.sh -s -y $(caljd.sh -p 1))
echo "Yesterday = ${YESTERDAY}"

Invoke as caljd.sh -u for full usage and examples.

Re: Reg Previous date calculation

Jdamian — Thu, 04 Mar 2004 09:40:20 GMT

I miss tools and utilities to handle dates and times.