fsx

Extended filesystem abstractions for golang!

About

fsx provides a package that extends the io/fs package from the standard library with functionality to create and modify files and directories.

The package defines an interface fsx.FS that embeds fs.FS and adds methods to modify files and directories. Those methods have been modeled after the corresponding functions from the os package. In addition an interface fsx.File embeds fs.File and adds methods found on os.File type.

Similar to fs, which defines additional interfaces for implementations that provide specific functionality (i.e. to read a directory, such as fs.ReadDirFS) this package defines extra interfaces for operations like

• create file
• write file
• create symlink
• remove file
• remove dir

Installation

go get github.com/halimath/fsx

Usage examples

osfs

The following example demonstrates how to use the osfs subpackage which provides fsx compatible abstractions using the os package to access files and directories from the local fs.

// Create a temporary directory to use as a root
dir, err := os.MkdirTemp("", "fsx_example_*")
if err != nil {
    panic(err)
}
// Make sure the directory is removed at the end of the test.
defer os.RemoveAll(dir)

// Create a fsx.FS using the temp dir.
fsys := osfs.DirFS(dir)

// Create a file inside the fsys.
f, err := fsx.Create(fsys, "test.md")
if err != nil {
    panic(err)
}

// Write some content to the file.
if _, err := f.Write([]byte("# fsx example test\n\nThis is just an example.")); err != nil {
    panic(err)
}

if err := f.Close(); err != nil {
    panic(err)
}

// Create a symlink inside the fsys
if err := fsys.Symlink("test.md", "README.md"); err != nil {
    panic(err)
}

// Now try to read the symlinked file using os functions.
content, err := os.ReadFile(filepath.Join(dir, "README.md"))
if err != nil {
    panic(err)
}

memfs

The subpackage memfs provides an in-memory implementation of fsx interfaces.

// Create a fsx.FS using the temp dir.
fsys := memfs.New()

// Create a file inside the fsys.
f, err := fsx.Create(fsys, "test.md")
if err != nil {
    panic(err)
}

// Write some content to the file.
if _, err := f.Write([]byte("# fsx example test\n\nThis is just an example.")); err != nil {
    panic(err)
}

if err := f.Close(); err != nil {
    panic(err)
}

// Create a symlink inside the fsys
if err := fsys.Symlink("test.md", "README.md"); err != nil {
    panic(err)
}

// Now try to read the symlinked file using fs.ReadFile
content, err := fs.ReadFile(fsys, "README.md")
if err != nil {
    panic(err)
}

License

Copyright 2023 Alexander Metzner.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.