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Re: the splits



Running lsof | grep seems a bit silly. Can't you just do lsof $mountpoint?

When I want to select columns I usually reach for awk:

 sudo lsof $mountpoint | awk '{print $1, $NF}'

No need to read all text into a variable when you can just send it straight to the screen.

On Tue, May 21, 2024 at 1:43 PM Ray Andrews <rayandrews@xxxxxxxxxxx> wrote:
A function of mine might need to unmount someting.  If there's a problem I try to be helpful:


umount -v "$mountpoint" ||
{
    # Helpful diagnostics if partition won't unmount:
    echo "\nCan't unmount $mountpoint.  Is a terminal logged on?  Or is it one of these programs:?\n(Please wait or press '^C' to quit.)"

    abc=$(lsof | grep $mountpoint)
    abc=( ${(f)abc} )
    for def in $abc[@]; do ghi=( ${=def} ); print -- "$ghi[1]\t$ghi[-1]\n"; done
    return
}       

Typical run:


% mnt ,U sda

Unmounting partitions ...
umount: /mnt/sda/1: target is busy.

Can't unmount /mnt/sda/1.  Is a terminal logged on?  Or is it one of these programs:?
(Please wait or press '^C' to quit.)

zsh      /mnt/sda/1/EFI/BOOT
geany    /mnt/sda/1/EFI/BOOT
geany    /mnt/sda/1/EFI/BOOT
geany    /mnt/sda/1/EFI/BOOT

----------------------------------------------------

... works fine but I'll bet:

abc=$(lsof | grep $mountpoint)
abc=( ${(f)abc} )
for def in $abc[@]; do ghi=( ${=def} ); print -- "$ghi[1]\t$ghi[-1]\n"; done


... is belabored.   Can that be streamlined?  As always my splitting is a problem.  I need to process line by line, but then word by word so as to grab just the first and last words from 'lsof' output.  I'll bet Roman can do all of the above in 20 characters.




--
Mark J. Reed <markjreed@xxxxxxxxx>


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