CODEWITHSUNDEEP
linuxshellvariablesunixawk
Narkon
Narkon

Reputation: 398

Read variable from AWK

I'm trying to get memory info by this command:

#!/bin/bash
set -x
cat /proc/meminfo | grep "MemFree" | tail -n 1 | awk '{ print $2 $4 }' | read numA numB
echo $numA

I'm getting this

+ awk '{ print $2 $4 }'
+ read numA numB
+ tail -n 1
+ grep MemFree
+ cat /proc/meminfo
+ echo

My attempts to read these data to variable were unsuccessful. My question is how I can read this to variables? I want to read how many memory is free like: 90841312 KB

Regards

Upvotes: 3

Views: 1053

Answers (4)

Ed Morton
Ed Morton

Reputation: 204731

arr=( $(awk '/MemFree/{split($0,a)} END{print a[2], a[4]}' /proc/meminfo) )
echo "${arr[0]}"
echo "${arr[1]}"

Upvotes: 0

dawg
dawg

Reputation: 104111

BTW: If you print multiple vales from awk, you need a separator:

$ echo "11 22" | awk '{print $1 }'
11
$ echo "11 22" | awk '{print $2}'
22
$ echo "11 22" | awk '{print $1 $2}'
1122
 ^ note no space there...

You either need a comma:

$ echo "11 22" | awk '{print $1,$2}'
11 22

Or physicality:

$ echo "11 22" | awk '{print $1"    "$2}'
11    22

Because without separation, the command substitution not read what you intend:

$ read -r f1 f2 <<< $(echo "11 22" | awk '{print $1 $2}')
$ echo $f1
1122
echo $f2

# f1 got two fields and nada for f2

Upvotes: 0

anubhava
anubhava

Reputation: 786359

Using BASH you can reduce your complex commands to this:

read -r _ numA _ numB < <(grep MemFree /proc/meminfo | tail -n 1)

Upvotes: 3

Beggarman
Beggarman

Reputation: 896

Assign the output directly to your variable:

var=$(cat /proc/meminfo | grep "MemFree" | tail -n 1 | awk '{ print $2 $4 }')
echo $var

Upvotes: 4

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