Re: cut(1) and space delimiters

[Mike McClain <mike.junk@nethere.com>]

On Fri, Mar 19, 2010 at 09:34:47PM -0500, Ron Johnson wrote:
> Googled and followed examples, which work, but my specific problem 
> doesn't work...
> 
> WORKS:
> $ service="http mail ssh"
> $ echo $service | cut -d\  -f2
> mail
> $ echo $service | cut -d' ' -f2
> mail
> dpkg --get-selections | grep -v deinstall$ | awk '{print $1}'
> 
> 
> DOES NOT WORK:
> $ dpkg --get-selections | grep -v deinstall$ | cut -d' ' -f1
> $ dpkg --get-selections | grep -v deinstall$ | cut -d\  -f1
> 
> 
> Is the problem that there's so *much* whitespace in the dpkg listing?

Two things are biting you.
First, on my system, 
'dpkg --get-selections | head -n1 | hd' shows tabs not spaces.

so use dpkg --get-selections | grep -v deinstall$ | cut -f1
The cut man page says tab is the default delimiter

Second, "cut -d' '" requires one space separating each field.

You could also use either of these:
dpkg --get-selections | grep -v deinstall$ | awk '{print $1;}'
dpkg --get-selections | grep -v deinstall$ | perl -nale' print $F[0];'

Mike
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