Date: Wed, 3 Mar 2004 10:18:40 -0600 From: Dan Nelson <dnelson@allantgroup.com> To: Wayne Sierke <ws+freebsd-questions@au.dyndns.ws> Cc: freebsd-questions@freebsd.org Subject: Re: Size of variables in awk Message-ID: <20040303161840.GD79860@dan.emsphone.com> In-Reply-To: <1078304560.666.157.camel@ovirt.dyndns.ws> References: <1078286126.666.11.camel@ovirt.dyndns.ws> <20040303080359.GB79860@dan.emsphone.com> <1078304560.666.157.camel@ovirt.dyndns.ws>
next in thread | previous in thread | raw e-mail | index | archive | help
In the last episode (Mar 03), Wayne Sierke said:
> On Wed, 2004-03-03 at 18:34, Dan Nelson wrote:
> > In the last episode (Mar 03), Wayne Sierke said:
> > > It seems I've run into the 32-bit signed number wall in awk
> > > (5.2-RELEASE).
> > >
> > > My totals are maxing out at 2147483648.
> > >
> > > Would anyone happen to know whether that's really the case (that awk is
> > > only implemented with 32-bit number capability - unfortunately I don't
> > > have any other awks nearby to verify nor can I find any reference info
> > > that indicates) and/or can suggest a way around it?
> >
> > Seems to works fine on -current:
> >
> > $ jot 8 30 | awk '{ print 2^$1 }'
>
> Ah, ok. Same for me on 5.2-RELEASE. More info:
>
> I'm using the printf function in awk but something ain't right:
>
> # jot 4 30 | awk '{ printf("%u\n", 2^$1-1) }'
> 2147483648
>
> # jot 4 30 | awk '{ printf("%lu\n", 2^$1-1) }'
> 2147483648
>
> # jot 4 30 | awk '{ printf("%llu\n", 2^$1-1) }'
> 35186519572480
I see nothing wrong here. %u is an unsigned int, and on x86 systems,
an int is 32 bits. %llu is a long long unsigned int, and they are 64
bits. Since there is no way for C to print a number larger than 64
bits, you won't be able to use the numeric specifiers to print large
numbers. You can use %s though. See
/usr/src/contrib/one-true-awk/run.c, the format() function.
--
Dan Nelson
dnelson@allantgroup.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040303161840.GD79860>