As a number of the commenters have said, using the shell for this kind of conversion is a horrible idea. And, it would be nigh impossible to do it with just bash builtins; and shell scripts are used to combine standard unix commands like sed, awk, cut, etc. anyway. You should choose a better language that's built for that kind of iterative parsing/processing to solve your problem.
However, because it's late and I've had too much coffee, I threw together a bash script (with a few bits of sed thrown in for parsing help) that takes the example .csv data you have and outputs the JSON in the format you noted. Here's the script:
#! /bin/bash
# Initial input file format:
#
# Africa,Kenya,NAI,281
# Africa,Kenya,NAA,281
# Asia,India,NSI,100
# Asia,India,BSE,160
# Asia,Pakistan,ISE,100
# Asia,Pakistan,ANO,100
# European Union,United Kingdom,LSE,100
#
# Intermediate file format for parsing to JSON:
#
# Africa|Kenya:NAI=281
# Asia|India:BSE=160&NSI=100|Pakistan:ISE=100&ANO=100
# European Union|United Kingdom:LSE=100
#
# Call as:
#
# $ ./script INPUTFILE.csv >OUTPUTFILE.json
#
# temporary files for output/parsing
TMP="./tmp.dat"
TMP2="./tmp2.dat"
>$TMP
>$TMP2
# read through initial file and output intermediate format
while read line
do
region=$(echo $line | cut -d, -f1)
country=$(echo $line | cut -d, -f2)
code=$(echo $line | cut -d, -f3)
size=$(echo $line | cut -d, -f4)
# region record already started
if grep "^$region" $TMP 2>&1 >/dev/null ;then
>$TMP2
while read rec
do
if echo $rec | grep "^$region" 2>&1 >/dev/null
then
if echo "$rec" | grep "\|$country:" 2>&1 >/dev/null
then
echo "$rec" | sed -e 's/\('"$country"':[^\|][^\|]*\)/\1\&'"$code"'='"$size"'/' >>$TMP2
else
echo "$rec|$country:$code=$size" >>$TMP2
fi
else
echo $rec >>$TMP2
fi
done < $TMP
mv $TMP2 $TMP
else
# new region
echo "$region|$country:$code=$size" >>$TMP
fi
done < $1
# Parse through our intermediary format and output JSON to standard out
echo "["
country_count=$(cat $TMP | wc -l)
while read line
do
country=$(echo $line | cut -d\| -f1)
echo "{ \"name\": \"$country\", "
echo " \"children\": ["
region_count=$(echo $line | cut -d\| -f2- | sed -e 's/|/\n/g' | wc -l)
echo $line | cut -d\| -f2- | sed -e 's/|/\n/g' |
while read region
do
name=$(echo $region | cut -d: -f1)
echo " { \"name\": \"$name\", "
echo " \"children\": ["
code_count=$(echo $region | sed -e 's/^'"$name"'://' -e 's/&/\n/g' | wc -l)
echo $region | sed -e 's/^'"$name"'://' -e 's/&/\n/g' |
while read code_size
do
code=$(echo $code_size | cut -d= -f1)
size=$(echo $code_size | cut -d= -f2)
code_count=$((code_count - 1))
COMMA=""
if [ $code_count -gt 0 ]; then
COMMA=","
fi
echo " { \"name\": \"$code\", \"size\": \"$size\" }$COMMA "
done
echo " ]"
region_count=$((region_count - 1))
if [ $region_count -gt 0 ]; then
echo " },"
else
echo " }"
fi
done
echo " ]"
country_count=$((country_count - 1))
COMMA=""
if [ $country_count -gt 0 ]; then
COMMA=","
fi
echo "}$COMMA"
done < $TMP
echo "]"
exit 0
And, here's the resulting output from the above script:
[
{ "name": "Africa",
"children": [
{ "name": "Kenya",
"children": [
{ "name": "NAI", "size": "281" },
{ "name": "NAA", "size": "281" }
]
}
]
},
{ "name": "Asia",
"children": [
{ "name": "India",
"children": [
{ "name": "NSI", "size": "100" },
{ "name": "BSE", "size": "160" }
]
},
{ "name": "Pakistan",
"children": [
{ "name": "ISE", "size": "100" },
{ "name": "ANO", "size": "100" }
]
}
]
},
{ "name": "European Union",
"children": [
{ "name": "United Kingdom",
"children": [
{ "name": "LSE", "size": "100" }
]
}
]
}
]
Please don't use code like the above in any production environment.
