Merge pull request #3 from jtbg/i2c_search

move i2c search into main function

dasung/utils.go

@@ -6,10 +6,15 @@ import (
  "os/exec"
  "strings"
  "log"
+ "context"
+ "time"
 )
 
 func FindDasungI2CDevicePaths() ([]string, error) {
- cmd := exec.Command("ddcutil", "detect", "--verbose")
+ ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+ defer cancel()
+ cmd := exec.CommandContext(ctx, "ddcutil", "detect", "--verbose")
+ //cmd := exec.Command("ddcutil", "detect", "--verbose")
  var out bytes.Buffer
  cmd.Stdout = &out
  err := cmd.Run()

go.mod

@@ -2,4 +2,4 @@ module github.com/jtbg/paperlike-go
 
 go 1.18
 
-require golang.org/x/exp v0.0.0-20230419192730-864b3d6c5c2c
+require golang.org/x/exp v0.0.0-20230419192730-864b3d6c5c2c

paperlike-cli/main.go

@@ -37,6 +37,20 @@ func init() {
 }
 
 func main() {
+ flag.Parse()
+
+ if *flagDevicePath == "" {
+ path, err := dasung.FindDasungI2CDevicePaths()
+ if err != nil {
+ log.Fatal("Failed to find Dasung Paperlike display:", err)
+ }
+ *flagDevicePath = path[0]
+ }
+
+ if !strings.HasPrefix(filepath.Clean(*flagDevicePath), "/dev/i2c-") {
+ log.Fatal("invalid device path (must start with /dev/i2c-)")
+ }
+
  d, err := dasung.NewDasungControl(*flagDevicePath)
  if err != nil {
  log.Fatal(err)