cmd/app: optionally override configured command

Useful for multiple applications sharing state.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/app/app.go

@@ -80,7 +80,7 @@ func parse(id string, base *check.Absolute, r io.Reader) (*hst.Config, error) {
 			Shell:    shell,
 			Home:     home,
 			Path:     shell,
-			Args:     []string{"zsh", "-c"},
+			Args:     []string{"zsh", "-ic"},
 
 			Flags: hst.FCoverRun,
 		},

cmd/app/app_test.go

@@ -118,7 +118,7 @@ talk com.canonical.Unity
 				Home:     hst.AbsPrivateTmp.Append("home"),
 				Path:     fhs.AbsRoot.Append("bin", "zsh"),
 				Args: []string{
-					"zsh", "-c",
+					"zsh", "-ic",
 					"exec Discord --ozone-platform-hint=wayland",
 				},
 

cmd/app/main.go

@@ -141,6 +141,10 @@ func main() {
 		)
 	}
 
+	{
+		var (
+			flagCommand string
+		)
 		c.NewCommand(
 			"run", "Start the named application",
 			func(args []string) error {
@@ -189,9 +193,19 @@ func main() {
 					return err
 				}
 
+				if flagCommand != "" {
+					config.Container.Args[2] = flagCommand
+				}
+
 				return run(ctx, msg, config)
 			},
+		).
+			Flag(
+				&flagCommand,
+				"command", command.StringFlag(""),
+				"Override configured command",
 			)
+	}
 
 	c.MustParse(os.Args[1:], func(err error) {
 		if e, ok := errors.AsType[*exec.ExitError](err); ok && e != nil {