alternative to readarray, because it does not work on mac os x

Question

I have a varsValues.txt file

cat varsValues.txt
aa=13.7
something=20.6
countries=205
world=1
languages=2014
people=7.2
oceans=3.4

And I would like to create 2 arrays, vars and values. It should contain

echo ${vars[@]}
aa something countries world languages people oceans

echo ${values[@]}
13.7 20.6 205 1 2014 7.2 3.4

I use

Npars=7

readarray -t vars < <(cut -d '=' -f1 varsValues.txt)
readarray -t values < <(cut -d '=' -f2 varsValues.txt)

for (( yy=0; yy<$Npars; yy++ )); do
eval ${vars[$yy]}=${values[$yy]}
done

echo $people
7.2

But I would like it without readarray which does not work on Mac (os x) and IFS (interfield separater).

Any other solution? awk? perl? which I can use in my bash script.

Thanks.

Solution 1

Here's the awk version. Note that NPars is not hardcoded.

vars=($(awk -F= '{print $1}' varsValues.txt))
values=($(awk -F= '{print $2}' varsValues.txt))

Npars=${#vars[@]}

for ((i=0; i<$Npars; i++)); do
    eval ${vars[$i]}=${values[$i]}
done

echo $people

Solution 2

You could use a read loop.

while IFS=\= read var value; do
    vars+=($var)
    values+=($value)
done < VarsValues.txt

Solution 3

You can use declare bulletin:

declare -a vars=( $(cut -d '=' -f1 varsValues.txt) )
declare -a values=( $(cut -d '=' -f2 varsValues.txt) )

Solution 4

Let's start with this:

$ awk -F'=' '{values[$1]=$2} END{print values["people"]}' file
7.2

$ awk -F'=' '{values[$1]=$2} END{for (name in values) print name, values[name]}' file
languages 2014
oceans 3.4
world 1
something 20.6
countries 205
people 7.2
aa 13.7

Now - what else do you need to do?

Solution 5

perl -0777 -nE '@F= split /[=\r\n]/; say "@F[grep !($_%2), 0..$#F]"; say "@F[grep $_%2, 0..$#F]"' varsValues.txt

or by reading same file twice,

perl -F'=' -lane 'print $F[0]' varsValues.txt
perl -F'=' -lane 'print $F[1]' varsValues.txt

View more solutions

Comments

[msw]

And then what? These doesn't populate shell variables as the sample script does.

[Jotne]

It should work without the declare, just: vars=($(cut -d '=' -f1 varsValues.txt)) work fine on my Ubuntu.

[anubhava]

That's right it should work without declare -a also.

[chepner]

+1 This would be preferred even if readarray were available, as it avoids external processes and a second pass through the file.

[amc]

In my implementation the code works without values+=($value) to create an array, where array items can be listed with ${vars[@]}.

[blubb]

This solution works perfectly, but pay attention to (the absence of) whitespace in vars+=($var). Using vars += ($var) does not work, which surprised me a bit.