An example of using GridFS in MongoDB.

main.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"labix.org/v2/mgo"
	"os"
	"path"
	"strings"
)

func main() {
	// Initialize the mongodb connection.
	session, err := mgo.Dial("localhost")
	if err != nil {
		fmt.Printf("initializing session:", err)
		return
	}
	defer session.Close()

	// Get our GridFS collection.
	gfs := session.DB("test").GridFS("")

	scanner := bufio.NewScanner(os.Stdin)
	quit := false

	for !quit {
		fmt.Print("gfs> ")

		if !scanner.Scan() {
			break
		}

		line := scanner.Text()
		parts := strings.Split(line, " ")
		cmd := parts[0]
		args := parts[1:]

		switch cmd {
		// List and find are the same. They only differ in the filter.
		case "put":
			file, err := os.Open(args[0])
			if err != nil {
				fmt.Println("opening file:", err)
				continue
			}

			gfile, err := gfs.Create(path.Base(args[0]))
			if err != nil {
				fmt.Println("creating grid file:", err)
				file.Close()
				continue
			}

			io.Copy(gfile, file)
			file.Close()
			gfile.Close()
		case "get":
			gfile, err := gfs.Open(args[0])
			if err != nil {
				fmt.Println("getting file:", err)
				continue
			}

			io.Copy(os.Stdout, gfile)
			gfile.Close()
		case "quit":
			quit = true
		default:
			fmt.Println("unrecognized command:", cmd, args)
		}
	}

	if err := scanner.Err(); err != nil {
		fmt.Println("reading stdin:", err)
	}
}