Convert easily a CSV into a JSON using Go

csv2json.go

package main

import (
	"encoding/csv"
	"encoding/json"
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strconv"
	"strings"
)

func string2realtype(thing string) any {
	if real, err := strconv.Atoi(thing); err == nil {
		return real
	}

	if real, err := strconv.ParseFloat(thing, 64); err == nil {
		return real
	}

	if real, err := strconv.ParseBool(thing); err == nil {
		return real
	}

	return thing
}

func csvname2jsonname(basename string) string {
	nameWithoutExtension := strings.TrimSuffix(basename, filepath.Ext(basename))
	return nameWithoutExtension + ".json"
}

func main() {
	var inputFilename, outputFilename string
	flag.StringVar(&inputFilename, "i", "", "Path to the input CSV")
	flag.StringVar(&outputFilename, "o", "", "Path to the output JSON")
	flag.Parse()

	if inputFilename == "" {
		flag.Usage()
		fmt.Println("Input csv is mandatory")
		return
	}

	if outputFilename == "" {
		outputFilename = csvname2jsonname(inputFilename)
	}

	csvfile, err := os.Open(inputFilename)
	if err != nil {
		fmt.Println("Error opening CSV file:", err)
		return
	}
	defer csvfile.Close()

	reader := csv.NewReader(csvfile)
	records, err := reader.ReadAll()
	if err != nil {
		fmt.Println("Error reading CSV records:", err)
		return
	}

	var jsonData []map[string]any
	for _, record := range records[1:] {
		entry := make(map[string]any)
		for i, value := range record {
			entry[records[0][i]] = string2realtype(value)
		}
		jsonData = append(jsonData, entry)
	}

	jsonfile, err := os.Create(outputFilename)
	if err != nil {
		fmt.Println("Error creating file:", err)
		return
	}

	err = json.NewEncoder(jsonfile).Encode(jsonData)
	if err != nil {
		fmt.Println("Error encoding JSON:", err)
		return
	}
}