From: Peter Stephenson <pws@ibmth.df.unipi.it>
To: Phil Pennock <phil@athenaeum.demon.co.uk>
Cc: zsh-workers@math.gatech.edu
Subject: Re: Bug? in 'integer' behaviour
Date: Mon, 05 Oct 1998 09:47:44 +0200 [thread overview]
Message-ID: <9810050747.AA12241@ibmth.df.unipi.it> (raw)
In-Reply-To: "Phil Pennock"'s message of "Mon, 05 Oct 1998 00:18:03 DFT." <199810042318.AAA05187@athenaeum.demon.co.uk>
Phil Pennock wrote:
> In the distribution is Functions/randline which purports to show a
> random line from a file. The problem seems to be caused by a variable
> declared integer not stripping off leading whitespace when assigned to.
>
> randline:
> # get a random line from a file
> integer z=$(wc -l <"$1")
> sed -n $[RANDOM%z+1]p "$1"
>
> This produces a divide by zero error, as 'z' is always zero. Removing
> the 'integer' keyword solves this, as does wrapping the RHS of the
> assignment in $[...].
I think it's the trailing characters after the number which are causing
the problem. From wc you get something like
128 .zshrc
and if you do
integer z=" 128 .zshrc"
you get
zsh: bad math expression: illegal character: .
But I get that from the $[...] expression too. I get the same
behaviour in ksh, except that there is an error message from the
$(...), so it looks standard. As a workaround you could do:
integer z=${$(wc -l <"$1")%"$1"}
or in a more standard way
y=$(wc -l <"$1")
integer z=${y%"$1"}
--
Peter Stephenson <pws@ibmth.df.unipi.it> Tel: +39 050 844536
WWW: http://www.ifh.de/~pws/
Gruppo Teorico, Dipartimento di Fisica
Piazza Torricelli 2, 56100 Pisa, Italy
next prev parent reply other threads:[~1998-10-05 8:09 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-10-04 23:18 Phil Pennock
1998-10-05 7:47 ` Peter Stephenson [this message]
1998-10-05 9:20 ` Bart Schaefer
1998-10-05 9:33 ` Peter Stephenson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=9810050747.AA12241@ibmth.df.unipi.it \
--to=pws@ibmth.df.unipi.it \
--cc=phil@athenaeum.demon.co.uk \
--cc=zsh-workers@math.gatech.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/zsh/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).