Optimizes images using pingo/jpegtran

optimize.go

package main

import (
	"fmt"
	"github.com/h2non/filetype"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
)

func main() {
	var files []string

	folder := os.Args[1]

	filepath.Walk(folder, func(path string, info os.FileInfo, err error) error {
		if info.IsDir() {
			return nil
		}
		files = append(files, path)
		return nil
	})

	fileList, _ := os.Create("file_list.args")

	workers := 5
	sem := make(chan bool, workers)

	for i, file := range files {
		sem <- true
		go func(i int, file string) {
			defer func() { <-sem }()
			buf, _ := ioutil.ReadFile(file)

			kind, unknown := filetype.Match(buf)
			if unknown != nil {
				return
			}

			if filetype.IsImage(buf) {
				fmt.Fprintln(fileList, file)
				if (kind.MIME.Value == "image/png") {
					os.MkdirAll("pimgs", 0777)
					os.Symlink(file, "pimgs/" + strconv.Itoa(i) + filepath.Ext(file))
				}

				if (kind.MIME.Value == "image/jpeg") {
					cmd := exec.Command("exiftool" , "-p", "'$colorcomponents'", file)
					out, _ := cmd.CombinedOutput()
					if strings.Trim(strings.TrimSpace(string(out)),`'`) == "1" {
						os.MkdirAll("pimgs", 0777)
						os.Symlink(file, "pimgs/" + strconv.Itoa(i) + filepath.Ext(file))
					} else {
						cmd := exec.Command("jpegtran", "-copy", "none", "-optimize", "-progressive", "-outfile", file, file)
						_, err := cmd.CombinedOutput()
						if err != nil {
							fmt.Println(err)
						}
					}
				}
			}
		}(i, file)
	}

	for i := 0; i < cap(sem); i++ {
		sem <- true
	}

	if _, err := os.Stat("pimgs/"); !os.IsNotExist(err) {
	    cmd := exec.Command("bash", "-c", "wine ~/go/src/optimize/pingo.exe pimgs -s8")
	    out, _ := cmd.CombinedOutput()
	    fmt.Print(string(out))
	}

	out, _ := exec.Command("exiftool", "-overwrite_original", "-all=", "-@", "file_list.args" ).Output()
	fmt.Print(string(out))

	os.RemoveAll("pimgs")
	os.RemoveAll("file_list.args")
}