Parse String in a Bash script

jimwelc · 01-20-2005, 04:24 PM

Hello,

I am very new to bash scripting and I am trying to break down a string into a few a few separate strings.

Basically I have a Version string I retrieve from a file( for example sake lets say it is "1.0.65.105" and I would like to break it down and store it into three separte strings/or numbers. I think I might be able to use the awk command and key off of the '.' (period) tag but I can not figure out the usage.

Any suggestions or help will be greatly appreciate.

Best Regards,
-Jim

mjrich · 01-20-2005, 05:09 PM

Yes, you could use any of sed, awk or cut. Have a look at this and this thread for recent discussions of the same problem.

Cheers,

mj

avarus · 01-20-2005, 05:15 PM

And don't forget 'tr'.

foo='1.2.3.4'
bar=(`echo $foo | tr '.' ' '`)
echo ${bar[1]}

TIM

homey · 01-20-2005, 05:49 PM

Quote:

And don't forget 'tr'.

You beat me to it avarus!

Code:

#!/bin/bash
n=0
a=/home/file.txt
for i in `cat ${a} | tr '.' '\n'` ; do
   str=${str},${i}
   let n=$n+1
   var=`echo "var${n}"`
   echo $var is ... ${i}
done

jlinkels · 01-20-2005, 08:51 PM

If you are programming in bash, you can't do without this document:

http://www.tldp.org/LDP/abs/html/

jlinkels

jimwelc · 01-21-2005, 09:06 AM

Thank you everyone for you help. It is all appreciated.

Cheers!

trogersls · 04-01-2009, 01:48 PM

The best way to do this would be:

echo "1.0.65.105" | awk 'BEGIN {FS="."}{print $1, $2, $3, $4}'

The results would be:

1 0 65 105

Or you could use:

echo "1.0.65.105" | tr '.' ' '

The results would be:

1 0 65 105

Constantine · 11-08-2012, 05:09 PM

v=1.2.3.4; IFS='.' a=($v); echo first=${a[0]}, all: ${a[*]};

David the H. · 11-09-2012, 07:47 AM

Code:

$ v='1.0.65.105'

$ IFS=. read -a v <<<"$v"

$ printf '%s\n' "${v[@]}"
1
0
65
105

Doing it this way has an advantage in that the resetting of IFS only applies to the read command, and not the shell as a whole.

There are lots of string manipulations available in bash.

Edit: I just noticed this is an almost 8 year old thread.

@Constantine: Reopening old threads is generally discouraged, although its usually acceptable if you have something substantial to add to that conversation, like you did here. But even then you should at least make it clear that you have re-opened it.

Thanks!