You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: head.go
    path of file: ./repos/sliver/client/command/filesystem
    
    the code of the file until where you have to start completion: package filesystem

/*
	Sliver Implant Framework
	Copyright (C) 2023  Bishop Fox

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

import (
	"context"
	"fmt"

	"github.com/bishopfox/sliver/client/console"
	"github.com/bishopfox/sliver/protobuf/clientpb"
	"github.com/bishopfox/sliver/protobuf/sliverpb"
	"github.com/spf13/cobra"
	"google.golang.org/protobuf/proto"
)

func HeadCmd(cmd *cobra.Command, con *console.SliverClient, args []string, head bool) {
	session, beacon := con.Act
    
func HeadCmd(cmd *cobra.Command, con *console.SliverClient, args []string, head bool) {
	session, beacon := con.ActiveTarget.GetInteractive()
	if session == nil && beacon == nil {
		return
	}

	var filePath string
	var fetchBytes bool
	var fetchSize int64
	var operationName string
	var download *sliverpb.Download
	var err error

	if len(args) > 0 {
		filePath = args[0]
	}
	if filePath == "" {
		con.PrintErrorf("Missing parameter: file name\n")
		return
	}

	if cmd.Flags().Changed("bytes") {
		fetchBytes = true
		fetchSize, _ = cmd.Flags().GetInt64("bytes")
		if fetchSize < 0 {
			// Cannot fetch a negative number of bytes
			con.PrintErrorf("The number of bytes specified must be positive.")
			return
		}
		if fetchSize == 1 {
			operationName = "byte"
		} else {
			operationName = "bytes"
		}
	} else if cmd.Flags().Changed("lines") {
		fetchBytes = false
		fetchSize, _ = cmd.Flags().GetInt64("lines")
		if fetchSize < 0 {
			// Cannot fetch a negative number of lines
			con.PrintErrorf("The number of lines specified must be positive.")
			return
		}
		if fetchSize == 1 {
			operationName = "line"
		} else {
			operationName = "lines"
		}
	} else {
		con.PrintErrorf("A number of bytes or a number of lines must be specified.")
		return
	}

	ctrl := make(chan bool)
	con.SpinUntil(fmt.Sprintf("Retrieving %d %s from %s ...", fetchSize, operationName, filePath), ctrl)

	// A tail is a negative head
	if !head {
		fetchSize *= -1
	}

	if fetchBytes {
		download, err = con.Rpc.Download(context.Background(), &sliverpb.DownloadReq{
			Request:          con.ActiveTarget.Request(cmd),
			Path:             filePath,
			MaxBytes:         fetchSize,
			RestrictedToFile: true,
		})
	} else {
		download, err = con.Rpc.Download(context.Background(), &sliverpb.DownloadReq{
			Request:          con.ActiveTarget.Request(cmd),
			Path:             filePath,
			MaxLines:         fetchSize,
			RestrictedToFile: true,
		})
	}

	ctrl <- true
	<-ctrl
	if err != nil {
		con.PrintErrorf("%s\n", err)
		return
	}
	if download.Response != nil && download.Response.Async {
		con.AddBeaconCallback(download.Response.TaskID, func(task *clientpb.BeaconTask) {
			err = proto.Unmarshal(task.Response, download)
			if err != nil {
				con.PrintErrorf("Failed to decode response %s\n", err)
				return
			}
			PrintCat(download, cmd, con)
		})
		con.PrintAsyncResponse(download.Response)
	} else {
		PrintCat(download, cmd, con)
	}
}