[lug] My script work on real "ksh" but not "bash"

[Jeffrey Haemer]

Dave,

It's not the loop that's biting you, it's the pipe.

$ x=2.718; x=3.14; echo $x
3.14
$ x=6.02e23; x=6 | x = 9; echo $x
6.02e23

Bash runs each piece of a pipeline in its own subshell.

Hope this helps.

On Thu, Sep 4, 2008 at 1:45 PM, Dave Pitts <dpitts at cozx.com> wrote:

> Hello:
>
> I've got a script (below) that works as expected under the Korn Shell (ksh)
> but fails under Bash. It acts as if the variables have some kind of scope
> issues as they are null after exiting the loop.
>
> It's probably something simple; but I can't see the problem...
>
> The script:
>
> #!/bin/bash
> typeset srclist=""
> typeset tarlist=""
>
> if [ "$1" = "" ];then
>  echo "Usage: $0 statusfile"
>  exit 1
> fi
> cat $1 | while read line
> do
>   if [ "${line}xx" = "xx" ]; then
>     break
>   fi
>   tag=`echo $line | awk '{print $2}'`
>   if [ "${tag}xx" = "Volume:xx" ]; then
>       while [ "$line" != "Component Volumes:" ]
>       do
>          read line
>       done
>       endline=""
>       while [[ -z "${endline}" ]]
>       do
>           read line
>           if [[ "$?" -ne 0 ]]; then
>               echo "ReadStatusFailed:"
>               exit 1
>           fi
>           case "${line}" in
>               *\ SOURCE\ *|*\ SOURCE)
>                   srcvol=`echo $line | awk '{print $1}'`
>                   ;;
>               *\ UPTODATE\ *|*\ UPTODATE)
>                   tarvol=`echo $line | awk '{print $1}'`
>                   endline="TARGET"
>                  ;;
>               *\ SCRATCH\ *|*\ SCRATCH)
>                   endline="TARGET"
>                  ;;
>
>           esac
>       done
>       srclist="$srclist $srcvol"
>       tarlist="$tarlist $tarvol"
>   fi
>   echo "inloop: srclist = " $srclist ", tarlist = " $tarlist
>   echo "    srcvol = " $srcvol ", tarvol = " $tarvol
> done
> echo "outloop: srclist = " $srclist ", tarlist = " $tarlist
> if [[ -z "${srclist}" ]]; then
>  echo "IT's BROKE"
> else
>  echo "It worked"
> fi
> exit
>
> The data:
>
> Group Volume:     Vol1
> Component Volumes:
>  /dev/dasdc1                SOURCE
>  /dev/dasdc2                UPTODATE
>
>
> So, if anybody sees an issue here. Please let me know...
> Thanks.
>
> PS. re: System Load - I FINALLY got it all to work after they replaced the
> disk drive and found some wrongly placed jumpers on the motherboard.
>
> --
> Dave Pitts             PULLMAN: Travel and sleep in safety and comfort.
> dpitts at cozx.com        My other RV IS a Pullman (Colorado Pine).
> http://www.cozx.com
>
> _______________________________________________
> Web Page:  http://lug.boulder.co.us
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>



-- 
Jeffrey Haemer <jeffrey.haemer at gmail.com>
720-837-8908 [cell]
http://goyishekop.blogspot.com
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