[SOLVED] Extract specific words from a line by using Shell

jegadezz · 06-10-2016, 09:28 AM

I hope someone here can help me. I have a line in a text file looking like this:

Disk /dev/mmcblk0: 15.7 GB, 15737028608 bytes, 30736384 sectors

I want to extract only the Size of mmcblk0.

I would prefer the solution being bash using sed or grep.

Thank you in advance,

TB0ne · 06-10-2016, 09:54 AM

Quote:

Originally Posted by jegadezz

I hope someone here can help me. I have a line in a text file looking like this:

Disk /dev/mmcblk0: 15.7 GB, 15737028608 bytes, 30736384 sectors

I want to extract only the Size of mmcblk0. I would prefer the solution being bash using sed or grep.

Ok..we'll be glad to HELP you, so what have you done/tried to do this?? Read the "Question Guidelines" in my posting signature...asking us to do this for you is fairly rude, as is even specifying what you want it done IN.

To start, read the man page on grep, then read the man page on either awk or cut. You can build your own solution from those.

EDIT:
Much like some of your other threads, where you simply asked for a handout:
http://www.linuxquestions.org/questi...in-4175574824/
http://www.linuxquestions.org/questi...er-4175576806/
http://www.linuxquestions.org/questi...nt-4175580501/

grail · 06-10-2016, 10:12 AM

Have to agree here ... at least have a go

jegadezz · 06-10-2016, 10:23 AM

Thank You TB0ne. you Push me to do my self and Finally I found the trick by own.

fdisk -l |grep -w "/dev/mmcblk0" |cut -d':' -f2|cut -c1-5

dab1414 · 06-10-2016, 10:28 AM

I haven't used sed much, but curious if this would this work?

Code:

fdisk -l | sed -n '/mmcblk0:/,/,/p'

grail · 06-10-2016, 01:10 PM

Quote:

Originally Posted by dab1414

I haven't used sed much, but curious if this would this work?

Code:

fdisk -l | sed -n '/mmcblk0:/,/,/p'

You don't have to be curious, try and see what you get? The only thing would be to first check the output of the fdisk command as you may not have an entry with 'mmcblk0' in it

@OP - your current solution assumes you already know the length of the string which refers to your size information, so you might get returned ' 15.7', but this gives you no real
idea of the size as there is no measurement, ie. MB,GB,TB ...

Knowing the format of the data I would use sed or awk as a quick and easy way to get the detail:

Code:

fdisk -l | sed -r '/mmcblk0:/s/^.*: ([^,]*).*/\1/'

fdisk -l | awk -F"[, ]" '/mmcblk0:/{print $3,$4}'