How to extract values from a command with multi-line output?

[Oliver Grawert]

hi,
Am Montag, dem 04.04.2022 um 20:40 +0200 schrieb Bo Berglund:
...
> $ fdisk -lu filename.img | tail -n 2
> filename.img1        8192
 532479  524288  256M  c W95 FAT32 (LBA)
> filename.img2      532480
3923967 3391488  1.6G 83 Linux
...
> The response from this command is two lines (one for each partition
> in the
> 
> image) and I am only interested in the 3 numbers on the two lines

you could read the lines with a while loop and assign each column to a
variable:

$ LC_ALL=C sudo fdisk -l jammy-desktop-amd64.iso | tail -3 
jammy-desktop-amd64.iso1      64 6688419 6688356  3.2G Microsoft basic
data
jammy-desktop-amd64.iso2 6688420 6696923    8504  4.2M EFI System
jammy-desktop-amd64.iso3 6696924 6697523     600  300K Microsoft basic
data
$

$ LC_ALL=C sudo fdisk -l jammy-desktop-amd64.iso | tail -3 | while read
-r name start end size type; do echo "$name $size $type"; done
jammy-desktop-amd64.iso1 6688356 3.2G Microsoft basic data
jammy-desktop-amd64.iso2 8504 4.2M EFI System
jammy-desktop-amd64.iso3 600 300K Microsoft basic data
$

just replace the 'echo "$name $size $type"' in that line with the code
you want to process any of the variables with or assign them to some
global variables outside the while loop ...

ciao
	oli
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