Add shelldash Option to Disable -- Appending in Shell Commands

eval.go

@@ -377,6 +377,8 @@ func (e *setExpr) eval(app *app, _ []string) {
 			return
 		}
 		gOpts.shellopts = strings.Split(e.val, ":")
+	case "shelldash", "noshelldash", "shelldash!":
+		err = applyBoolOpt(&gOpts.shelldash, e)
 	case "sizeunits":
 		switch e.val {
 		case "binary", "decimal":

opts.go

@@ -101,6 +101,7 @@ var gOpts struct {
 	shell            string
 	shellflag        string
 	shellopts        []string
+	shelldash        bool
 	showbinds        bool
 	sizeunits        string
 	smartcase        bool
@@ -264,6 +265,7 @@ func init() {
 	gOpts.shell = gDefaultShell
 	gOpts.shellflag = gDefaultShellFlag
 	gOpts.shellopts = nil
+	gOpts.shelldash = true
 	gOpts.showbinds = true
 	gOpts.sizeunits = "binary"
 	gOpts.smartcase = true

os.go

@@ -138,7 +138,11 @@ func shellCommand(s string, args []string) *exec.Cmd {
 		s = fmt.Sprintf("IFS='%s'; %s", gOpts.ifs, s)
 	}
 
-	args = append([]string{gOpts.shellflag, s, "--"}, args...)
+	if gOpts.shelldash {
+		args = append([]string{gOpts.shellflag, s, "--"}, args...)
+	} else {
+		args = append([]string{gOpts.shellflag, s}, args...)
+	}
 
 	args = append(gOpts.shellopts, args...)