Returns json created from pipe

key_value_pipe_to_json.sh

#!/bin/bash

# Example:
# > echo "key1 value1 key2 value2" | ./key_value_pipe_to_json.sh 
# {'key1': value1, 'key2': value2}

arr=();

while read x y; 
do 
    arr=("${arr[@]}" $x $y)
done

vars=(${arr[@]})
len=${#arr[@]}

printf "{"
for (( i=0; i<len; i+=2 ))
do
    printf "\"${vars[i]}\": ${vars[i+1]}"
    if [ $i -lt $((len-2)) ] ; then
        printf ", "
    fi
done
printf "}"
echo