main.go

package main

import (
	"compress/gzip"
	"encoding/csv"
	"flag"
	"log"
	"os"
)

// GZippedCSVWriter combines a file, gz writer, and csv writer
type GZippedCSVWriter struct {
	fout *os.File
	gw   *gzip.Writer
	*csv.Writer
}

func NewGzippedCSVWriter(fname string) (*GZippedCSVWriter, error) {
	fout, err := os.Create(fname)
	if err != nil {
		return nil, err
	}

	gzwr := gzip.NewWriter(fout)
	csvwriter := csv.NewWriter(gzwr)

	return &GZippedCSVWriter{
		fout:   fout,
		gw:     gzwr,
		Writer: csvwriter,
	}, nil
}

func (gz *GZippedCSVWriter) Close() error {
	gz.Flush()

	err := gz.gw.Close()
	if err != nil {
		return err
	}

	err = gz.fout.Close()
	if err != nil {
		return err
	}

	return nil
}

var (
	fname = flag.String("fname", "", "output fname")
)

func main() {
	out, err := NewGzippedCSVWriter(*fname)
	if err != nil {
		log.Fatal(err)
	}

	out.Write([]string{"doom", "doom", "doom"})

	err = out.Close()
	if err != nil {
		log.Fatal(err)
	}
}