Format output of multiple bash commands into columns

Question

What I want to do is simple enough, but I cannot get it done without several commands. This is what it looks like so far. I'd love to be able to do this in one sloppy looking line that just passes all the commands at once.

# cat /sys/class/scsi_host/host*/device/fc_host:host*/port_name >port
# cat /sys/class/scsi_host/host*/device/fc_host:host*/speed >speed
# cat /sys/class/scsi_host/host*/device/fc_host:host*/port_state >state
# paste -d ' ' port speed state
0x218000e01a0002d2 8 Gbit Online
0x218100e01a2002d2 8 Gbit Online

I've tried to do this with sub shells, variables, etc. The format ends up misaligned, or worse.

# echo "$port_name" "$speed" "$state"
0x218000e01a0002d2
0x218100e01a2002d2 8 Gbit
8 Gbit Online
Online

# paste -d ' ' "$(cat /sys/class/scsi_host/host*/device/fc_host:host*/port_name)" "$(cat /sys/class/scsi_host/host*/device/fc_host:host*/speed)"
paste: 0x218000e01a0002d2
0x218100e01a2002d2: No such file or directory

chepner · Accepted Answer · 2013-03-06 15:09:18Z

2

Instead of command substitution, try process substitution:

paste -d ' ' <(cat /sys/class/scsi_host/host*/device/fc_host:host*/port_name) \
             <(cat /sys/class/scsi_host/host*/device/fc_host:host*/speed) \
             <(cat /sys/class/scsi_host/host*/device/fc_host:host*/port_state)

answered Mar 6, 2013 at 15:09

chepner

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1 Comment

gNU.be Over a year ago

I have read up on process substitution before with tee, but that was confusing me. This puts it into an easier context.

demon_86_rm · Accepted Answer · 2014-04-16 11:02:02Z

-1

What about this?

for i in /sys/class/fc_host/host*; do (cd $i; echo -e "$(cat port_name)\t$(cat port_state)\t$(cat speed)"); done

edited Apr 16, 2014 at 11:02

answered Apr 16, 2014 at 9:25

demon_86_rm

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