open: allow overriding default program

Instead of xdg-open (or open on MacOS), allow forcing a program to open
a message part. The program is determined in that order of priority:

1) If :open has arguments, they will be used as command to open the
   attachment. If the arguments contain the {} placeholder, the
   temporary file will be substituted, otherwise the file path is added
   at the end of the arguments.

2) If a command is specified in the [openers] section of aerc.conf for
   the part MIME type, then it is used with the same rules of {}
   substitution.

3) Finally, fallback to xdg-open/open with the file path as argument.

Update the docs and default config accordingly with examples.

Fixes: https://todo.sr.ht/~rjarry/aerc/64
Co-authored-by: Jason Stewart <support@eggplantsd.com>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Tested-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>

1 files changed, 5 insertions, 3 deletions

diff --git a/commands/msgview/open.go b/commands/msgview/open.go
index 82c1accb..bb22026a 100644
--- a/commands/msgview/open.go
+++ b/commands/msgview/open.go
@@ -48,10 +48,11 @@ func (Open) Execute(aerc *widgets.Aerc, args []string) error {
 
 	mv.MessageView().FetchBodyPart(p.Index, func(reader io.Reader) {
 		extension := ""
+		mimeType := ""
+
 		// try to determine the correct extension based on mimetype
 		if part, err := mv.MessageView().BodyStructure().PartAtIndex(p.Index); err == nil {
-			mimeType := fmt.Sprintf("%s/%s", part.MIMEType, part.MIMESubType)
-
+			mimeType = fmt.Sprintf("%s/%s", part.MIMEType, part.MIMESubType)
 			if exts, _ := mime.ExtensionsByType(mimeType); len(exts) > 0 {
 				extension = exts[0]
 			}
@@ -71,7 +72,8 @@ func (Open) Execute(aerc *widgets.Aerc, args []string) error {
 		}
 
 		go func() {
-			err = lib.XDGOpen(tmpFile.Name())
+			openers := aerc.Config().Openers
+			err = lib.XDGOpenMime(tmpFile.Name(), mimeType, openers, args[1:])
 			if err != nil {
 				aerc.PushError("open: " + err.Error())
 			}