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Rizla

01-26-2011 11:54 AM

Creating array from command output (bash shell script)

Hi, I have a command that outputs n lines of text, and I want to place each line into an array element, but I can't seem to get the syntax correct

so my command is this:
cat $configfile | sed -n '/cluster:'$clustername'/,/cluster/ p' | awk /host/

which produces many lines depending on the value of $clustername. I'd like to get each line as elements of an array,

any help would be much appreciated,

Thanks

crts	01-26-2011 12:42 PM

Quote:

Originally Posted by Rizla (Post 4238452)

Hi,

you also need to fix your sed statement and the excessive piping.

Code:

#!/bin/bash

declare -a ARRAY

count=0

while read -r line; do

  var[((count++))]="$line"

done < <(sed -n "/cluster:$clustername/,/cluster/ {/host/ p}" "${configfile}")

everToulouse

01-26-2011 02:54 PM

Code:

#!/bin/bash



configfile=/path/to/file

clustername=whatever



while read -r line 

do

  [[ $line =~ cluster ]] && flag=0



  [[ $line =~ cluster:${clustername} ]] && flag=1



  if ((flag)) && [[ $line =~ host ]]; then Array+=("$line"); fi



done < "${configfile}"



printf '%s\n' "$Array[@]}"

I prefer not use external commands when I can avoid them.
without a representative sample of $configfile, it's hard to do better.
perhaps it's posible to do it without regexes.

colucix

01-26-2011 03:10 PM

Another way is by setting the IFS variable to newline only (and restore it to the default later). Following the suggestion by crts:

Code:

OLD_IFS=${IFS}

IFS=$'\n'

ARRAY=( $(sed -n "/cluster:$clustername/,/cluster/ {/host/ p}" "${configfile}") )

IFS=${OLD_IFS}

grail

01-26-2011 06:53 PM

@everToulouse - your Array is a string and not an Array. Try changing @ for a 1 and you will see there is no value stored there. Easy fix though, throw in some
brackets and your all good:

Code:

if ((flag)) && [[ $line =~ host ]]; then Array+=("$line"); fi

everToulouse

01-26-2011 10:47 PM

Hi grail,

oops!
corrected, thx.

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