Bash Parse File And Sort Strings: Key="number"

#!/bin/bash

# Youni Bash tutorial
# Parse File And Sort Strings: Key="number"
# cat db
# a="1110"
# b="100"
# C="1000"
#
# Expected result:
# b="100"
# C="1000"
# a="1110"


file='db'

#parse database file and fill arrays of keys and values
i=0
while IFS= read -r line
do
    i=$((i+1))
    echo "Pasrse line: $line";
    #key=$(echo $line | cut -d= -f1 | sed 's/[^_0-9A-Za-z]*\([_0-9A-Za-z]*\)[^_0-9A-Za-z]*/\1/')
    key=$(echo $line | cut -d= -f1 | grep -Po -m1 '[_A-Za-z]*')
    value=$(echo $line | cut -d= -f2 | grep -Po '[0-9]*' | head -n1)
    #value=$(echo $line | cut -d= -f2 | awk -F'[^0-9]*' '$0=$2')
    if [ -z $key ] || [ -z $value ]
    then
        echo Line $i is not valid
        exit 1
    fi
    echo "  key: $key"
    echo "  value: $value"
    arr_keys[$i]=$key
    arr_values[$i]=$value
done < $file

qnty=$i

#sort array by values numbers ascending
i=0
while [ $i -lt $qnty ]
do
    i=$((i+1))
    j=$i
    while [ $j -lt $qnty ]
    do
        j=$((j+1))
        if [[ ${arr_values[$j]} -lt ${arr_values[$i]} ]]
        then
            #swap
            key=${arr_keys[$i]}
            value=${arr_values[$i]}
            arr_keys[$i]=${arr_keys[$j]}
            arr_values[$i]=${arr_values[$j]}
            arr_keys[$j]=$key
            arr_values[$j]=$value
        fi
    done
done

#print result array
echo
echo 'Result array:'
i=0
while [ $i -lt $qnty ]
do
    i=$((i+1))
    echo ${arr_keys[$i]}'="'${arr_values[$i]}'"'
    #put the result to file
    # touch __tmp__
    # echo ${arr_keys[$i]}'="'${arr_values[$i]}'"' >> __tmp__
done
# mv __tmp__ $file