commands: Cleanup Requests after command execution returns

command.go

@@ -97,6 +97,14 @@ func (c *Command) Call(req Request) Response {
 		return res
 	}
 
+	// clean up the request (close the readers, e.g. fileargs)
+	// NOTE: this means commands can't expect to keep reading after cmd.Run returns (in a goroutine)
+	err = req.Cleanup()
+	if err != nil {
+		res.SetError(err, ErrNormal)
+		return res
+	}
+
 	res.SetOutput(output)
 	return res
 }

request.go

@@ -3,6 +3,7 @@ package commands
 import (
 	"errors"
 	"fmt"
+	"io"
 	"reflect"
 	"strconv"
 
@@ -28,6 +29,7 @@ type Request interface {
 	Context() *Context
 	SetContext(Context)
 	Command() *Command
+	Cleanup() error
 
 	ConvertOptions() error
 }
@@ -119,6 +121,20 @@ func (r *request) Command() *Command {
 	return r.cmd
 }
 
+func (r *request) Cleanup() error {
+	for _, arg := range r.arguments {
+		closer, ok := arg.(io.Closer)
+		if ok {
+			err := closer.Close()
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
 type converter func(string) (interface{}, error)
 
 var converters = map[reflect.Kind]converter{