first version

cmd/backlight-control.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"backlight-control/cmd/set"
+	"backlight-control/cmd/status"
+
+	"github.com/spf13/cobra"
+)
+
+var rootCmd *cobra.Command
+
+func main() {
+	rootCmd = &cobra.Command{
+		Use:          "backlight-control",
+		Short:        "backlight control tool",
+		SilenceUsage: true,
+		Run: func(cmd *cobra.Command, args []string) {
+			cmd.Help()
+		},
+	}
+
+	rootCmd.PersistentFlags().String("path", "", "control file directory path (/path/to/dir/{brightness,max_brightness})")
+
+	if err := rootCmd.MarkPersistentFlagRequired("path"); err != nil {
+		panic(err)
+	}
+
+	set.NewCommand(rootCmd)
+	status.NewCommand(rootCmd)
+
+	if err := rootCmd.Execute(); err != nil {
+		panic(err)
+	}
+}

cmd/set/set.go

@@ -0,0 +1,132 @@
+package set
+
+import (
+	"backlight-control/internal/backlight"
+	"errors"
+	"fmt"
+	"regexp"
+	"strconv"
+
+	"github.com/spf13/cobra"
+)
+
+func NewCommand(parent *cobra.Command) {
+	cmd := &cobra.Command{
+		Use:     "set [+/-]VAL[%]",
+		Aliases: []string{"s"},
+		Args:    cobra.ExactArgs(1),
+		RunE:    run,
+		Short:   "set backlight value",
+	}
+
+	parent.AddCommand(cmd)
+}
+
+type operate int
+
+const (
+	None operate = 1 << iota
+	Equal
+	Add
+	Subtract
+)
+
+var changeValueRegex = regexp.MustCompile(`^([+-])?(\d+(\.\d+)?)%?$`)
+
+func parseChange(val string) (op operate, value float32, err error) {
+
+	find := changeValueRegex.FindAllStringSubmatch(val, -1)
+	if find == nil || len(find) < 1 {
+		return None, 0, errors.New("input value pattern invalid")
+	}
+
+	findList := find[0]
+	if len(findList) < 3 {
+		return None, 0, fmt.Errorf("parsed value invalid, %v", findList)
+	}
+
+	opStr := findList[1]
+	valStr := findList[2]
+
+	switch opStr {
+	case "+":
+		op = Add
+	case "-":
+		op = Subtract
+	default:
+		op = Equal
+	}
+
+	f64, err := strconv.ParseFloat(valStr, 32)
+	if err != nil {
+		return None, 0, fmt.Errorf("parse value to float fail: (%w)", err)
+	}
+
+	value = float32(f64)
+
+	return
+}
+
+func run(cmd *cobra.Command, args []string) (err error) {
+	dirPath, err := cmd.Flags().GetString("path")
+	if err != nil {
+		return fmt.Errorf("get directory path from flags fail: (%w)", err)
+	}
+	_ = dirPath
+
+	op, value, err := parseChange(args[0])
+	if err != nil {
+		return err
+	}
+
+	lightInstance, err := backlight.NewInstance(dirPath)
+	if err != nil {
+		return fmt.Errorf("create backlight instance fail: %w", err)
+	}
+
+	cur, err := lightInstance.GetCurrent()
+	if err != nil {
+		return fmt.Errorf("get current brightness fail: %w", err)
+	}
+	max, err := lightInstance.GetMax()
+	if err != nil {
+		return fmt.Errorf("get max brightness fail: %w", err)
+	}
+
+	// cale percentage
+	curP := float32(int(float32(cur)/float32(max)*10000)) / 100
+
+	// 1% base
+	oneP := float32(max) / 100
+
+	finalVal := 0
+
+	switch op {
+	case Add:
+		finalVal = int((curP + value) * oneP)
+		if finalVal > max {
+			finalVal = max
+		}
+	case Subtract:
+		finalVal = int((curP - value) * oneP)
+		if finalVal < 0 {
+			finalVal = 0
+		}
+	case Equal:
+		if value > 100 {
+			value = 100
+		} else if value < 0 {
+			value = 0
+		}
+		finalVal = int((value) * oneP)
+	default:
+		return errors.New("operate invalid")
+	}
+
+	err = lightInstance.SetValue(finalVal)
+	if err != nil {
+		return fmt.Errorf("set backlight to target value fail: %w", err)
+	}
+
+	return
+}

cmd/status/status.go

@@ -0,0 +1,66 @@
+package status
+
+import (
+	"backlight-control/internal/backlight"
+	"encoding/json"
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+func NewCommand(parent *cobra.Command) {
+	cmd := &cobra.Command{
+		Use:     "status",
+		Aliases: []string{"st"},
+		RunE:    run,
+		Short:   "get backlight status (current,max,percentage)",
+	}
+
+	parent.AddCommand(cmd)
+}
+
+type backlightStatus struct {
+	Current    int     `json:"current"`
+	Max        int     `json:"max"`
+	Percentage float32 `json:"percentage"`
+}
+
+func run(cmd *cobra.Command, args []string) (err error) {
+	dirPath, err := cmd.Flags().GetString("path")
+	if err != nil {
+		return fmt.Errorf("get directory path from flags fail: (%w)", err)
+	}
+
+	lightInstance, err := backlight.NewInstance(dirPath)
+	if err != nil {
+		return fmt.Errorf("create backlight instance fail: %w", err)
+	}
+
+	cur, err := lightInstance.GetCurrent()
+	if err != nil {
+		return fmt.Errorf("get current brightness fail: %w", err)
+	}
+	max, err := lightInstance.GetMax()
+	if err != nil {
+		return fmt.Errorf("get max brightness fail: %w", err)
+	}
+
+	status := backlightStatus{
+		Current: cur,
+		Max:     max,
+	}
+
+	// cale percentage
+	f := float32(int(float32(cur)/float32(max)*10000)) / 100
+
+	status.Percentage = f
+
+	b, err := json.Marshal(status)
+	if err != nil {
+		return err
+	}
+
+	fmt.Println(string(b))
+
+	return
+}

go.mod

@@ -0,0 +1,13 @@
+module backlight-control
+
+go 1.19
+
+require (
+	git.trj.tw/golang/utils v0.0.0-20190225142552-b019626f0349
+	github.com/spf13/cobra v1.6.1
+)
+
+require (
+	github.com/inconshreveable/mousetrap v1.0.1 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+)

go.sum

@@ -0,0 +1,12 @@
+git.trj.tw/golang/utils v0.0.0-20190225142552-b019626f0349 h1:V6ifeiJ3ExnjaUylTOz37n6z5uLwm6fjKjnztbTCaQI=
+git.trj.tw/golang/utils v0.0.0-20190225142552-b019626f0349/go.mod h1:yE+qbsUsijCTdwsaQRkPT1CXYk7ftMzXsCaaYx/0QI0=
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/inconshreveable/mousetrap v1.0.1 h1:U3uMjPSQEBMNp1lFxmllqCPM6P5u/Xq7Pgzkat/bFNc=
+github.com/inconshreveable/mousetrap v1.0.1/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.6.1 h1:o94oiPyS4KD1mPy2fmcYYHHfCxLqYjJOhGsCHFZtEzA=
+github.com/spf13/cobra v1.6.1/go.mod h1:IOw/AERYS7UzyrGinqmz6HLUo219MORXGxhbaJUqzrY=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/backlight/backlight.go

@@ -0,0 +1,71 @@
+package backlight
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"git.trj.tw/golang/utils"
+)
+
+type Backlight struct {
+	Directory string
+}
+
+const currentValueFile = "brightness"
+const maxValueFile = "max_brightness"
+
+func NewInstance(path string) (*Backlight, error) {
+	bl := &Backlight{Directory: path}
+
+	if !utils.CheckExists(path, true) {
+		return nil, fmt.Errorf("backlight class directory check fail")
+	}
+
+	// check brightness and max_brightness file exists
+	brightnessFile := filepath.Join(path, currentValueFile)
+	maxBrightnessFile := filepath.Join(path, maxValueFile)
+
+	if !utils.CheckExists(brightnessFile, false) {
+		return nil, fmt.Errorf("brightness file check fail")
+	}
+	if !utils.CheckExists(maxBrightnessFile, false) {
+		return nil, fmt.Errorf("max_brightness file check fail")
+	}
+
+	return bl, nil
+}
+
+func readBrightnessValue(file string) (val int, err error) {
+	cnt, err := os.ReadFile(file)
+	if err != nil {
+		return 0, err
+	}
+
+	val, err = strconv.Atoi(strings.TrimSpace(string(cnt)))
+	if err != nil {
+		return 0, err
+	}
+
+	return
+}
+
+func (b *Backlight) GetCurrent() (val int, err error) {
+	return readBrightnessValue(filepath.Join(b.Directory, currentValueFile))
+}
+
+func (b *Backlight) GetMax() (val int, err error) {
+	return readBrightnessValue(filepath.Join(b.Directory, maxValueFile))
+}
+
+func (b *Backlight) SetValue(val int) (err error) {
+	brightness := filepath.Join(b.Directory, "brightness")
+
+	if err := os.WriteFile(brightness, []byte(fmt.Sprintf("%d", val)), 0644); err != nil {
+		return err
+	}
+
+	return
+}