Is there a way to create key-value pairs in Bash s

Question

I am trying to create a dictionary of key value pair using Bash script. I am trying using this logic:

declare -d dictionary
defaults write "$dictionary" key -string "$value"

...where $dictionary is a variable, but this is not working.

Is there a way to create key-value pairs in Bash script?

Answer 1

In bash version 4 associative arrays were introduced.

declare -A arr

arr["key1"]=val1

arr+=( ["key2"]=val2 ["key3"]=val3 )

The arr array now contains the three key value pairs. Bash is fairly limited what you can do with them though, no sorting or popping etc.

for key in ${!arr[@]}; do
    echo ${key} ${arr[${key}]}
done

Will loop over all key values and echo them out.

Answer 2

If you can use a simple delimiter, a very simple oneliner is this:

for i in a,b c_s,d ; do 
  KEY=${i%,*};
  VAL=${i#*,};
  echo $KEY" XX "$VAL;
done

Hereby i is filled with character sequences like "a,b" and "c_s,d". each separated by spaces. After the do we use parameter substitution to extract the part before the comma , and the part after it.

Answer 3

For persistent key/value storage, you can use kv-bash, a pure bash implementation of key/value database available at https://github.com/damphat/kv-bash

Usage

git clone https://github.com/damphat/kv-bash
source kv-bash/kv-bash

Try create some permanent variables

kvset myName  xyz
kvset myEmail [e-mail]

#read the varible
kvget myEmail

#you can also use in another script with $(kvget keyname)
echo $(kvget myEmail)