open: run commands with sh -c

Allow running shell commands in openers.

Changelog-changed: `:open` commands are now executed with `sh -c`.
Requested-by: Vitaly Ovchinnikov <v@postbox.nz>
Signed-off-by: Robin Jarry <robin@jarry.cc>
Reviewed-by: Koni Marti <koni.marti@gmail.com>
Tested-by: Moritz Poldrack <moritz@poldrack.dev>
Tested-by: Inwit <inwit@sindominio.net>

8 files changed, 30 insertions, 38 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd8e3259..4551909e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -61,6 +61,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   *.default=true
   *.normal=true
   ```
+- Openers commands are not executed in with `sh -c`.
 
 ### Deprecated
 
diff --git a/commands/msg/unsubscribe.go b/commands/msg/unsubscribe.go
index a489b3b9..6fef16f5 100644
--- a/commands/msg/unsubscribe.go
+++ b/commands/msg/unsubscribe.go
@@ -180,7 +180,7 @@ func unsubscribeHTTP(u *url.URL) error {
 				go func() {
 					defer log.PanicHandler()
 					mime := fmt.Sprintf("x-scheme-handler/%s", u.Scheme)
-					if err := lib.XDGOpenMime(u.String(), mime, nil); err != nil {
+					if err := lib.XDGOpenMime(u.String(), mime, ""); err != nil {
 						app.PushError("Unsubscribe:" + err.Error())
 					}
 				}()
diff --git a/commands/msgview/open-link.go b/commands/msgview/open-link.go
index ad2a7cc2..55aee08c 100644
--- a/commands/msgview/open-link.go
+++ b/commands/msgview/open-link.go
@@ -12,7 +12,7 @@ import (
 
 type OpenLink struct {
 	Url *url.URL `opt:"url" action:"ParseUrl"`
-	Cmd []string `opt:"..." required:"false"`
+	Cmd string   `opt:"..." required:"false"`
 }
 
 func init() {
diff --git a/commands/msgview/open.go b/commands/msgview/open.go
index bab46bd7..0d6db5b0 100644
--- a/commands/msgview/open.go
+++ b/commands/msgview/open.go
@@ -13,8 +13,8 @@ import (
 )
 
 type Open struct {
-	Delete bool     `opt:"-d"`
-	Cmd    []string `opt:"..." required:"false"`
+	Delete bool   `opt:"-d"`
+	Cmd    string `opt:"..." required:"false"`
 }
 
 func init() {
diff --git a/config/aerc.conf b/config/aerc.conf
index 18c6decc..06cfb2d1 100644
--- a/config/aerc.conf
+++ b/config/aerc.conf
@@ -548,9 +548,10 @@ message/rfc822=colorize
 # actions on a per-MIME-type basis. The :open-link URL scheme is used to
 # determine the MIME type as follows: x-scheme-handler/<scheme>.
 #
-# {} is expanded as the temporary filename to be opened. If it is not
-# encountered in the command, the temporary filename will be appened to the end
-# of the command.
+# {} is expanded as the temporary filename or URL to be opened with proper
+# shell quoting. If it is not encountered in the command, the filename/URL will
+# be appended to the end of the command. The command will then be executed with
+# `sh -c`.
 #
 # Like [filters], openers support basic shell globbing. The first opener which
 # matches the part's MIME type (or URL scheme handler MIME type) will be used,
@@ -558,7 +559,7 @@ message/rfc822=colorize
 #
 # Examples:
 # x-scheme-handler/irc=hexchat
-# x-scheme-handler/http*=firefox
+# x-scheme-handler/http*=printf '%s' {} | wl-copy
 # text/html=surf -dfgms
 # text/plain=gvim {} +125
 # message/rfc822=thunderbird
diff --git a/config/openers.go b/config/openers.go
index e246ea64..31d99e9c 100644
--- a/config/openers.go
+++ b/config/openers.go
@@ -1,17 +1,15 @@
 package config
 
 import (
-	"fmt"
 	"strings"
 
 	"git.sr.ht/~rjarry/aerc/log"
 	"github.com/go-ini/ini"
-	"github.com/google/shlex"
 )
 
 type Opener struct {
 	Mime string
-	Args []string
+	Args string
 }
 
 var Openers []Opener
@@ -24,14 +22,7 @@ func parseOpeners(file *ini.File) error {
 
 	for _, key := range openers.Keys() {
 		mime := strings.ToLower(key.Name())
-		if args, err := shlex.Split(key.Value()); err != nil {
-			return err
-		} else {
-			if len(args) == 0 {
-				return fmt.Errorf("opener command empty for %s", mime)
-			}
-			Openers = append(Openers, Opener{Mime: mime, Args: args})
-		}
+		Openers = append(Openers, Opener{Mime: mime, Args: key.Value()})
 	}
 
 out:
diff --git a/doc/aerc-config.5.scd b/doc/aerc-config.5.scd
index 0e86e56b..a45e2443 100644
--- a/doc/aerc-config.5.scd
+++ b/doc/aerc-config.5.scd
@@ -900,9 +900,10 @@ actions on a per-MIME-type basis. The *:open-link* URL scheme is used to
 determine the MIME type as follows: _x-scheme-handler/<scheme>_. They are
 configured in the *[openers]* section of _aerc.conf_.
 
-_{}_ is expanded as the temporary filename or URL to be opened. If it is not
-encountered in the command, the filename/URL will be appened to the end of the
-command. Environment variables are also expanded. Tilde is not expanded.
+_{}_ is expanded as the temporary filename or URL to be opened with proper shell
+quoting. If it is not encountered in the command, the filename/URL will be
+appended to the end of the command. The command will then be executed with
+_sh -c_.
 
 Like *[filters]*, openers support basic shell globbing. The first opener which
 matches the part's MIME type (or URL scheme handler MIME type) will be used, so
@@ -913,7 +914,7 @@ Example:
 ```
 [openers]
 x-scheme-handler/irc=hexchat
-x-scheme-handler/http\*=firefox
+x-scheme-handler/http\*=printf '%s' {} | wl-copy
 text/html=surf -dfgms
 text/plain=gvim {} +125
 message/rfc822=thunderbird
diff --git a/lib/open.go b/lib/open.go
index b60c4165..21bee748 100644
--- a/lib/open.go
+++ b/lib/open.go
@@ -6,19 +6,21 @@ import (
 	"runtime"
 	"strings"
 
+	"git.sr.ht/~rjarry/go-opt"
+	"github.com/danwakefield/fnmatch"
+
 	"git.sr.ht/~rjarry/aerc/config"
 	"git.sr.ht/~rjarry/aerc/log"
-	"github.com/danwakefield/fnmatch"
 )
 
 func XDGOpenMime(
-	uri string, mimeType string, args []string,
+	uri string, mimeType string, args string,
 ) error {
 	if len(args) == 0 {
 		// no explicit command provided, lookup opener from mime type
 		for _, o := range config.Openers {
 			if fnmatch.Match(o.Mime, mimeType, 0) {
-				args = append(args, o.Args...)
+				args = o.Args
 				break
 			}
 		}
@@ -26,28 +28,24 @@ func XDGOpenMime(
 	if len(args) == 0 {
 		// no opener defined in config, fallback to default
 		if runtime.GOOS == "darwin" {
-			args = append(args, "open")
+			args = "open"
 		} else {
-			args = append(args, "xdg-open")
+			args = "xdg-open"
 		}
 	}
 
-	i := 0
-	for ; i < len(args); i++ {
-		if strings.Contains(args[i], "{}") {
-			break
-		}
-	}
-	if i < len(args) {
+	// Escape URI special characters
+	uri = opt.QuoteArg(uri)
+	if strings.Contains(args, "{}") {
 		// found {} placeholder in args, replace with uri
-		args[i] = strings.Replace(args[i], "{}", uri, 1)
+		args = strings.Replace(args, "{}", uri, 1)
 	} else {
 		// no {} placeholder in args, add uri at the end
-		args = append(args, uri)
+		args = args + " " + uri
 	}
 
 	log.Tracef("running command: %v", args)
-	cmd := exec.Command(args[0], args[1:]...)
+	cmd := exec.Command("sh", "-c", args)
 	out, err := cmd.CombinedOutput()
 	log.Debugf("command: %v exited. err=%v out=%s", args, err, out)
 	if err != nil {