Re: shell script

From: Chris F.A. Johnson (cfajohnson_at_gmail.com)
Date: 07/16/04 

Date: 16 Jul 2004 09:43:07 GMT

On 2004-07-16, tibo wrote:
> Hello.
>
> I'm making a shell script that analyse this result of a command :
>
> bridge name bridge id STP enabled interfaces
> bridge0 8000.0090270d3c6a no eth0
>
> eth1
>
> eth2
> bridge1 8000.000000000000 no
>
> On this result, you can see that interface eth0, eth1 and eth2 are
> attached to bridge0 and that bridge1 has not interfaces attached.
>
> I'd like to do this analyse with a script.
>
> I tried with grep and awk stuff. But I have two problems :
>
> 1)
> On first line, "eth0" is in the 4th column
> On second and third lines, "eth1" and "eth2" are on the first column
>
> 2)
> The other problem is that I'd like to do something like :
>
> scan 4th column or 1st colum (to see "eth0", "eth1", "eth2") of each line
> after bridge0 until I meet "bridge1" on first column. But there's no "until"
> loop in shell script !
>
> Does anyone have an idea, some tip to give me ? Thanks a lot for your
> answers.

man bash:

    while list; do list; done
    until list; do list; done
          The while command continuously executes the do list as long as
          the last command in list returns an exit status of zero. The
          until command is identical to the while command, except that the
          test is negated; the do list is executed as long as the last
          command in list returns a non-zero exit status. The exit status
          of the while and until commands is the exit status of the last
          do list command executed, or zero if none was executed.
    ............

    But I don't think that's what you really want.

    Try (this is just a skeleton):

<COMMAND> | { read header ## discard first line
  while read col1 col2 col3 col4
  do
      case $col1 in
          bridge[0-9]*) : ;;
          *) ;;
      esac
  done
} 

-- 
    Chris F.A. Johnson                  http://cfaj.freeshell.org/shell
    ===================================================================
    My code (if any) in this post is copyright 2004, Chris F.A. Johnson
    and may be copied under the terms of the GNU General Public License

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