memfs

README

memfs: A simple in-memory io/fs.FS filesystem

memfs is an in-memory implementation of Go's io/fs.FS interface. The goal is to make it easy and quick to build an fs.FS filesystem when you don't have any complex requirements.

io/fs docs: https://tip.golang.org/pkg/io/fs/

Usage

package main

import (
	"fmt"
	"io/fs"

	"gomodules.xyz/memfs"
)

func main() {
	rootFS := memfs.New()

	err := rootFS.MkdirAll("dir1/dir2", 0777)
	if err != nil {
		panic(err)
	}

	err = rootFS.WriteFile("dir1/dir2/f1.txt", []byte("incinerating-unsubstantial"), 0755)
	if err != nil {
		panic(err)
	}

	err = fs.WalkDir(rootFS, ".", func(path string, d fs.DirEntry, err error) error {
		fmt.Println(path)
		return nil
	})
	if err != nil {
		panic(err)
	}

	content, err := fs.ReadFile(rootFS, "dir1/dir2/f1.txt")
	if err != nil {
		panic(err)
	}
	fmt.Printf("%s\n", content)
}

Documentation

Index

• type FS
  • func New() *FS
  • func (rootFS *FS) MkdirAll(path string, perm os.FileMode) error
  • func (rootFS *FS) Open(name string) (fs.File, error)
  • func (rootFS *FS) WriteFile(path string, data []byte, perm os.FileMode) error
• type File
  • func (f *File) Close() error
  • func (f *File) Read(b []byte) (int, error)
  • func (f *File) Stat() (fs.FileInfo, error)

Examples

• New

Types

type FS

type FS struct {
	// contains filtered or unexported fields
}

FS is an in-memory filesystem that implements io/fs.FS

func New

func New() *FS

New creates a new in-memory FileSystem.

Example

package main

import (
	"fmt"
	"io/fs"

	"gomodules.xyz/memfs"
)

func main() {
	rootFS := memfs.New()

	err := rootFS.MkdirAll("dir1/dir2", 0777)
	if err != nil {
		panic(err)
	}

	err = rootFS.WriteFile("dir1/dir2/f1.txt", []byte("incinerating-unsubstantial"), 0755)
	if err != nil {
		panic(err)
	}

	err = fs.WalkDir(rootFS, ".", func(path string, d fs.DirEntry, err error) error {
		fmt.Println(path)
		return nil
	})
	if err != nil {
		panic(err)
	}

	content, err := fs.ReadFile(rootFS, "dir1/dir2/f1.txt")
	if err != nil {
		panic(err)
	}
	fmt.Printf("%s\n", content)
}

func (*FS) MkdirAll

func (rootFS *FS) MkdirAll(path string, perm os.FileMode) error

MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error. The permission bits perm (before umask) are used for all directories that MkdirAll creates. If path is already a directory, MkdirAll does nothing and returns nil.

func (*FS) Open

func (rootFS *FS) Open(name string) (fs.File, error)

Open opens the named file.

func (*FS) WriteFile

func (rootFS *FS) WriteFile(path string, data []byte, perm os.FileMode) error

WriteFile writes data to a file named by filename. If the file does not exist, WriteFile creates it with permissions perm (before umask); otherwise WriteFile truncates it before writing, without changing permissions.

type File

type File struct {
	// contains filtered or unexported fields
}

func (*File) Close

func (f *File) Close() error

func (*File) Read

func (f *File) Read(b []byte) (int, error)

func (*File) Stat

func (f *File) Stat() (fs.FileInfo, error)