open: simplify code

There is no need for convoluted channels and other async fanciness.
Expose a single XDGOpen static function that runs a command and returns
an error if any.

Caller is responsible of running this in an async goroutine if needed.

Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>

commands/msg/unsubscribe.go

@@ -183,9 +183,11 @@ func unsubscribeHTTP(aerc *widgets.Aerc, u *url.URL) error {
 			aerc.CloseDialog()
 			switch option {
 			case "Yes":
-				if err := lib.NewXDGOpen(u.String()).Start(); err != nil {
-					aerc.PushError("Unsubscribe:" + err.Error())
-				}
+				go func() {
+					if err := lib.XDGOpen(u.String()); err != nil {
+						aerc.PushError("Unsubscribe:" + err.Error())
+					}
+				}()
 			default:
 				aerc.PushError("Unsubscribe: link will not be opened")
 			}

commands/msgview/open.go

@@ -5,11 +5,9 @@ import (
 	"io"
 	"mime"
 	"os"
-	"time"
 
 	"git.sr.ht/~rjarry/aerc/commands"
 	"git.sr.ht/~rjarry/aerc/lib"
-	"git.sr.ht/~rjarry/aerc/logging"
 	"git.sr.ht/~rjarry/aerc/widgets"
 )
 
@@ -40,8 +38,8 @@ func (Open) Execute(aerc *widgets.Aerc, args []string) error {
 	if args[0] == "open-link" && len(args) > 1 {
 		if link := args[1]; link != "" {
 			go func() {
-				if err := lib.NewXDGOpen(link).Start(); err != nil {
-					aerc.PushError(fmt.Sprintf("%s: %s", args[0], err.Error()))
+				if err := lib.XDGOpen(link); err != nil {
+					aerc.PushError("open: " + err.Error())
 				}
 			}()
 		}
@@ -64,34 +62,20 @@ func (Open) Execute(aerc *widgets.Aerc, args []string) error {
 			aerc.PushError(err.Error())
 			return
 		}
-		defer tmpFile.Close()
 
 		_, err = io.Copy(tmpFile, reader)
+		tmpFile.Close()
 		if err != nil {
 			aerc.PushError(err.Error())
 			return
 		}
 
-		xdg := lib.NewXDGOpen(tmpFile.Name())
-		// pass through any arguments the user provided to the underlying handler
-		if len(args) > 1 {
-			xdg.SetArgs(args[1:])
-		}
-		err = xdg.Start()
-		if err != nil {
-			aerc.PushError(err.Error())
-			return
-		}
 		go func() {
-			defer logging.PanicHandler()
-
-			err := xdg.Wait()
+			err = lib.XDGOpen(tmpFile.Name())
 			if err != nil {
-				aerc.PushError(err.Error())
+				aerc.PushError("open: " + err.Error())
 			}
 		}()
-
-		aerc.PushStatus("Opened", 10*time.Second)
 	})
 
 	return nil

lib/open.go

@@ -1,65 +1,25 @@
 package lib
 
 import (
+	"fmt"
 	"os/exec"
 	"runtime"
 
 	"git.sr.ht/~rjarry/aerc/logging"
 )
 
-var openBin string = "xdg-open"
-
-func init() {
+func XDGOpen(uri string) error {
+	openBin := "xdg-open"
 	if runtime.GOOS == "darwin" {
 		openBin = "open"
 	}
-}
-
-type xdgOpen struct {
-	args  []string
-	errCh chan (error)
-	cmd   *exec.Cmd
-}
-
-// NewXDGOpen returns a handler for opening a file via the system handler xdg-open
-// or comparable tools on other OSs than Linux
-func NewXDGOpen(filename string) *xdgOpen {
-	errch := make(chan error, 1)
-	return &xdgOpen{
-		errCh: errch,
-		args:  []string{filename},
-	}
-}
-
-// SetArgs sets additional arguments to the open command prior to the filename
-func (xdg *xdgOpen) SetArgs(args []string) {
-	args = append([]string{}, args...) // don't overwrite array of caller
-	filename := xdg.args[len(xdg.args)-1]
-	xdg.args = append(args, filename) //nolint:gocritic // intentional append to different slice
-}
-
-// Start the open handler.
-// Returns an error if the command could not be started.
-// Use Wait to wait for the commands completion and to check the error.
-func (xdg *xdgOpen) Start() error {
-	xdg.cmd = exec.Command(openBin, xdg.args...)
-	err := xdg.cmd.Start()
+	args := []string{openBin, uri}
+	logging.Infof("running command: %v", args)
+	cmd := exec.Command(args[0], args[1:]...)
+	out, err := cmd.CombinedOutput()
+	logging.Debugf("command: %v exited. err=%v out=%s", args, err, out)
 	if err != nil {
-		xdg.errCh <- err // for callers that just check the error from Wait()
-		close(xdg.errCh)
-		return err
+		return fmt.Errorf("%v: %w", args, err)
 	}
-	go func() {
-		defer logging.PanicHandler()
-
-		xdg.errCh <- xdg.cmd.Wait()
-		close(xdg.errCh)
-	}()
 	return nil
 }
-
-// Wait for the xdg-open command to complete
-// The xdgOpen must have been started
-func (xdg *xdgOpen) Wait() error {
-	return <-xdg.errCh
-}