From: "Russ Cox" <rsc@swtch.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
Subject: Re: [9fans] venti backup example vs. 2GB
Date: Mon, 25 Sep 2006 20:49:45 -0400 [thread overview]
Message-ID: <ee9e417a0609251749u4d654339u37548e813f3bae08@mail.gmail.com> (raw)
In-Reply-To: <432bc0dde71c69a75de5f60bf55915ec@tombob.com>
You can use %.0f to print the number from awk.
Russ
On 9/25/06, Robert Raschke <rrplan9@tombob.com> wrote:
> Hi,
>
> I've been using a backup script modelled on the example in
> /sys/src/cmd/venti/backup.example and the other day it "just" stopped
> working. On debugging I found that I have now reached the beginning
> of the fifth 500MB arena. The script uses awk to calculate the
> starting byte offset and that fails with a floating point error (!)
> when we go beyond the 2G mark.
>
> I resorted to a fairly brutal use of bc(1) and that seems to work.
> Here's what I use now (I flipped the 2nd and 3rd parameter to the x fn
> to make printing from bc easier):
>
> #!/bin/rc
>
> rfork e
> . bkup.info
> fn x {
> echo x $*
> y=$1
> if(~ $#$y 0){
> $y=0
> }
> echo venti/wrarena -h venti_backup_server -o $3 $2 $$y
> end=`{venti/wrarena -h venti_backup_server -o $3 $2 $$y | grep '^end offset ' | sed 's/^end offset //'}
> if(~ $#end 1 && ! ~ $$y $end){
> $y=$end
> echo '#' `{date} >>bkup.info
> whatis $y >>bkup.info
> }
> }
> hget http://127.1:8000/index |
> awk '
> /^index=/ { blockSize=0+substr($3, 11); }
> /^arena=/ { arena=substr($1, 7); }
> /^ arena=/ {
> start=substr($5, 2, index($5, ",")-2);
> printf("\"x \"; \"%s \"; \"%s \"; s=%s-%s; print s;", arena, $3, start, blockSize);
> }
> ' |bc -s |rc
>
>
> Robby
>
>
prev parent reply other threads:[~2006-09-26 0:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-09-25 21:11 Robert Raschke
2006-09-25 21:28 ` geoff
2006-09-25 21:53 ` geoff
2006-09-26 0:09 ` erik quanstrom
2006-09-26 0:12 ` geoff
2006-09-26 0:18 ` erik quanstrom
2006-09-26 0:49 ` Russ Cox [this message]
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