topic Re: rounding up in awk/shell in Operating System - HP-UX

rounding up in awk/shell

Stefan Farrelly — Tue, 08 Oct 2002 08:54:18 GMT

Hi all,

our usual memory.sh script which uses adb and the kernel to display the system memory total works fine on 10.20 and 11.0 but on 11.11 it computes to an integer instead of a round number, eg;

echo "phys_mem_pages/D" | adb /stand/vmunix /dev/kmem|grep phys|tail -1|awk '{printf $2/256}'

On our server with 768Mb of RAM shows 767.992

My question is how can we round this up in awk (should display 768) or using prinf. Ive tried but cant figure it. I know this can be done the long way in a shell script or probably in perl, definitely in C using round, but Im after a 1 liner using awk and/or printf to do it - and so that it works on servers with different memory sizes.

Thanks,

Stefan

Re: rounding up in awk/shell

Jean-Luc Oudart — Tue, 08 Oct 2002 09:00:45 GMT

Hi

echo "767.99" | awk '{printf("%d\n",$1 + 0.5);}'
768
echo "767.49" | awk '{printf("%d\n",$1 + 0.5);}'
767
echo "767.51" | awk '{printf("%d\n",$1 + 0.5);}'
768

Jean-Luc

Re: rounding up in awk/shell

Dietmar Konermann — Tue, 08 Oct 2002 09:03:27 GMT

What about

echo "phys_mem_pages/D" | adb /stand/vmunix /dev/kmem|tail -1|awk '{printf "%d",$2/256+.5}'

BTW, I dropped the grep... it failed on my 11.11 box.

Regards...
Dietmar.

Re: rounding up in awk/shell

Stefan Farrelly — Tue, 08 Oct 2002 09:12:03 GMT

Hey, come on guys, no simply adding 1 or .5 or whatever to it. I want to round up. Must be able to round with awk, or nawk, or bc or dc or bs ??? anyone ?

Re: rounding up in awk/shell

Dietmar Konermann — Tue, 08 Oct 2002 09:16:32 GMT

Hmmm, Stefan.

What's the differnence between rounding up X and rounding down (X+.5)? Why should a designer include such a redundant functionality? :)

Regards...
Dietmar.

Re: rounding up in awk/shell

H.Merijn Brand (procura — Tue, 08 Oct 2002 09:21:04 GMT

why awk?

# echo 767.992 | perl -ne'printf"%.0f\n",$_'
768
#

Re: rounding up in awk/shell

Stefan Farrelly — Tue, 08 Oct 2002 09:23:06 GMT

sorry, im purely being pedandtic. I want to round up or down using awk or a shell script in a one liner if possible. You can do in C, probably in perl, but not in a simple shell script/command ?

Re: rounding up in awk/shell

Stefan Farrelly — Tue, 08 Oct 2002 09:29:43 GMT

Hi Procura,

That did it! you dont need perl - your printf function is rounding perfectly (>.5 = up, < .5 round down). This now works;

echo "phys_mem_pages/D" | adb /stand/vmunix /dev/kmem|grep phys|tail -1|awk '{printf "%.0f MB\n",$2/256}'

Thanks!

Stefan

Re: rounding up in awk/shell

Jean-Luc Oudart — Tue, 08 Oct 2002 09:40:53 GMT

As far as I knwo round does not exist (in awk)
Well , I build it
You may like it or Not, just try to help

echo $1 | awk '
function round(aa) {
return int( aa + 0.5 )
}
{
printf("%d\n",round($1));
}'

Jean-Luc

Re: rounding up in awk/shell

Pete Randall — Tue, 08 Oct 2002 10:07:41 GMT

Stefan,

Thankyou for asking. I've just been accepting the answer as is and rounding up myself. This is much better.

Eternally grateful,
Pete

Re: rounding up in awk/shell

Tom Danzig — Tue, 08 Oct 2002 12:44:50 GMT

To round up using awk:
echo "767.992" | awk '{printf("%5.0f\n",$0)}'

To round down using awk:
echo "767.992" | awk '{printf("%d\n",$0)}'

Re: rounding up in awk/shell

Tom Danzig — Tue, 08 Oct 2002 12:53:19 GMT

To be more specific in my previous post, Using %5.0f actually will properly round the number up or down as expected. Using %d simply truncates off the decimals printing only the integer portion.

Re: rounding up in awk/shell

Stephen Serbe — Wed, 04 Dec 2002 19:14:14 GMT

Isn't the forum great...
I had the same question and found my answer(s) right here using search. Thanks, Stephen

Re: rounding up in awk/shell

Pete Randall — Wed, 04 Dec 2002 19:16:15 GMT

Psssst - Stephen!!! That's Stefan!

;^)

Pete