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

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.

Answer 1

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

Answer 2

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

Answer 3

You can use declare builtin:
declare -a vars=( $(cut -d '=' -f1 varsValues.txt) )
declare -a values=( $(cut -d '=' -f2 varsValues.txt) )
Although, as commenters have pointed out declare -a is superfluous.
vars=( $(cut -d '=' -f1 varsValues.txt) )
values=( $(cut -d '=' -f2 varsValues.txt) )
Works just as well.

Answer 4

Try:
IFS=$'\n' vars=($(cut -d '=' -f1 varsValues.txt))
IFS=$'\n' values=($(cut -d '=' -f2 varsValues.txt))

Answer 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

Answer 6

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?

Answer 7

Figured I'd toss this in here: https://raw.githubusercontent.com/AdrianTP/new-environment-setup/master/utils/readarray.sh
#!/bin/bash
# from: https://peniwize.wordpress.com/2011/04/09/how-to-read-all-lines-of-a-file-into-a-bash-array/
readarray() {
local __resultvar=$1
declare -a __local_array
let i=0
while IFS=$'\n' read -r line_data; do
__local_array[i]=${line_data}
((++i))
done < $2
if [[ "$__resultvar" ]]; then
eval $__resultvar="'${__local_array[#]}'"
else
echo "${__local_array[#]}"
fi
}
I keep this in a "utils" folder in my "new-environment-setup" Github repo, and I just clone it down and import it whenever I need to read a file into an array of lines an array get a new computer or wipe my drive. It should thus act as a backfill for readarray's shortcomings on Mac.
Import looks like:
# From: https://stackoverflow.com/a/12694189/771948
DIR="${BASH_SOURCE%/*}"
if [[ ! -d "$DIR" ]]; then DIR="$PWD"; fi
. "$DIR/utils/readarray.sh"
Usage looks like readarray "<output_var_name>" "<input_file_name>".
Yes it's a little rough. Sorry about that. It may not even work correctly anymore, but it did at one point, so I thought I would share it here to plant the idea of simply...writing your own backfill.

Answer 8

Mac uses an outdated version of bash (due to licencing reasons) by default which is lacking the readarray command.
This solution worked best for me (Mac user):
Check version of bash (probably version 3 from 2007)
bash --version
Download latest version of bash
brew install bash
Open a new terminal (which will load the new environment), then check the new version of bash (should be version 5 or higher)
bash --version
Check location(s) of bash
which -a bash
Output:
/usr/local/bin/bash
/bin/bash
You can see that you now have two versions of bash. Usually, both of these paths are in your PATH variable.
Check PATH variable
echo $PATH
The /usr/local/bin/bash should be standing before the /bin/bash in this variable. The shell is searching for executables in the order of occurrence in the PATH variable and takes the first one it finds.
Make sure to use a bash shell (rather than zsh) when using this command.
Try out the readarray command by e.g. redirecting the output of the ls
command with command substitution to the readarray command to generate an array containing a list with the filenames of the current folder:
readarray var < <(ls); echo ${var[#]}
Also, if you want to write a bash script make sure to use the correct Shebang:
#!/usr/local/bin/bash