Fs

https://raw.githubusercontent.com/wailsapp/wails/master/v2/internal/fs/fs.go

fs/fs.go

package fs

import (
    "crypto/md5"
    "fmt"
    "io"
    "io/fs"
    "os"
    "path/filepath"
    "runtime"
    "strings"
    "unsafe"

    "github.com/leaanthony/slicer"
)

// LocalDirectory gets the caller's file directory
// Equivalent to node's __DIRNAME
func LocalDirectory() string {
    _, thisFile, _, _ := runtime.Caller(1)
    return filepath.Dir(thisFile)
}

// RelativeToCwd returns an absolute path based on the cwd
// and the given relative path
func RelativeToCwd(relativePath string) (string, error) {
    cwd, err := os.Getwd()
    if err != nil {
        return "", err
    }

    return filepath.Join(cwd, relativePath), nil
}

// Mkdir will create the given directory
func Mkdir(dirname string) error {
    return os.Mkdir(dirname, 0755)
}

// MkDirs creates the given nested directories.
// Returns error on failure
func MkDirs(fullPath string, mode ...os.FileMode) error {
    var perms os.FileMode
    perms = 0755
    if len(mode) == 1 {
        perms = mode[0]
    }
    return os.MkdirAll(fullPath, perms)
}

// MoveFile attempts to move the source file to the target
// Target is a fully qualified path to a file *name*, not a
// directory
func MoveFile(source string, target string) error {
    return os.Rename(source, target)
}

// DeleteFile will delete the given file
func DeleteFile(filename string) error {
    return os.Remove(filename)
}

// CopyFile from source to target
func CopyFile(source string, target string) error {
    s, err := os.Open(source)
    if err != nil {
        return err
    }
    defer s.Close()
    d, err := os.Create(target)
    if err != nil {
        return err
    }
    if _, err := io.Copy(d, s); err != nil {
        d.Close()
        return err
    }
    return d.Close()
}

// DirExists - Returns true if the given path resolves to a directory on the filesystem
func DirExists(path string) bool {
    fi, err := os.Lstat(path)
    if err != nil {
        return false
    }

    return fi.Mode().IsDir()
}

// FileExists returns a boolean value indicating whether
// the given file exists
func FileExists(path string) bool {
    fi, err := os.Lstat(path)
    if err != nil {
        return false
    }

    return fi.Mode().IsRegular()
}

// RelativePath returns a qualified path created by joining the
// directory of the calling file and the given relative path.
//
// Example: RelativePath("..") in *this* file would give you '/path/to/wails2/v2/internal`
func RelativePath(relativepath string, optionalpaths ...string) string {
    _, thisFile, _, _ := runtime.Caller(1)
    localDir := filepath.Dir(thisFile)

    // If we have optional paths, join them to the relativepath
    if len(optionalpaths) > 0 {
        paths := []string{relativepath}
        paths = append(paths, optionalpaths...)
        relativepath = filepath.Join(paths...)
    }
    result, err := filepath.Abs(filepath.Join(localDir, relativepath))
    if err != nil {
        // I'm allowing this for 1 reason only: It's fatal if the path
        // supplied is wrong as it's only used internally in Wails. If we get
        // that path wrong, we should know about it immediately. The other reason is
        // that it cuts down a ton of unnecassary error handling.
        panic(err)
    }
    return result
}

// MustLoadString attempts to load a string and will abort with a fatal message if
// something goes wrong
func MustLoadString(filename string) string {
    data, err := os.ReadFile(filename)
    if err != nil {
        fmt.Printf("FATAL: Unable to load file '%s': %s\n", filename, err.Error())
        os.Exit(1)
    }
    return *(*string)(unsafe.Pointer(&data))
}

// MD5File returns the md5sum of the given file
func MD5File(filename string) (string, error) {
    f, err := os.Open(filename)
    if err != nil {
        return "", err
    }
    defer f.Close()

    h := md5.New()
    if _, err := io.Copy(h, f); err != nil {
        return "", err
    }

    return fmt.Sprintf("%x", h.Sum(nil)), nil
}

// MustMD5File will call MD5File and abort the program on error
func MustMD5File(filename string) string {
    result, err := MD5File(filename)
    if err != nil {
        println("FATAL: Unable to MD5Sum file:", err.Error())
        os.Exit(1)
    }
    return result
}

// MustWriteString will attempt to write the given data to the given filename
// It will abort the program in the event of a failure
func MustWriteString(filename string, data string) {
    err := os.WriteFile(filename, []byte(data), 0755)
    if err != nil {
        fatal("Unable to write file", filename, ":", err.Error())
        os.Exit(1)
    }
}

// fatal will print the optional messages and die
func fatal(message ...string) {
    if len(message) > 0 {
        print("FATAL:")
        for text := range message {
            print(text)
        }
    }
    os.Exit(1)
}

// GetSubdirectories returns a list of subdirectories for the given root directory
func GetSubdirectories(rootDir string) (*slicer.StringSlicer, error) {
    var result slicer.StringSlicer

    // Iterate root dir
    err := filepath.Walk(rootDir, func(path string, info os.FileInfo, err error) error {
        if err != nil {
            return err
        }
        // If we have a directory, save it
        if info.IsDir() {
            result.Add(path)
        }
        return nil
    })
    return &result, err
}

func DirIsEmpty(dir string) (bool, error) {

    // CREDIT: https://stackoverflow.com/a/30708914/8325411
    f, err := os.Open(dir)
    if err != nil {
        return false, err
    }
    defer f.Close()

    _, err = f.Readdirnames(1) // Or f.Readdir(1)
    if err == io.EOF {
        return true, nil
    }
    return false, err // Either not empty or error, suits both cases
}

// CopyDir recursively copies a directory tree, attempting to preserve permissions.
// Source directory must exist, destination directory must *not* exist.
// Symlinks are ignored and skipped.
// Credit: https://gist.github.com/r0l1/92462b38df26839a3ca324697c8cba04
func CopyDir(src string, dst string) (err error) {
    src = filepath.Clean(src)
    dst = filepath.Clean(dst)

    si, err := os.Stat(src)
    if err != nil {
        return err
    }
    if !si.IsDir() {
        return fmt.Errorf("source is not a directory")
    }

    _, err = os.Stat(dst)
    if err != nil && !os.IsNotExist(err) {
        return
    }
    if err == nil {
        return fmt.Errorf("destination already exists")
    }

    err = MkDirs(dst)
    if err != nil {
        return
    }

    entries, err := os.ReadDir(src)
    if err != nil {
        return
    }

    for _, entry := range entries {
        srcPath := filepath.Join(src, entry.Name())
        dstPath := filepath.Join(dst, entry.Name())

        if entry.IsDir() {
            err = CopyDir(srcPath, dstPath)
            if err != nil {
                return
            }
        } else {
            // Skip symlinks.
            if entry.Type()&os.ModeSymlink != 0 {
                continue
            }

            err = CopyFile(srcPath, dstPath)
            if err != nil {
                return
            }
        }
    }

    return
}

// CopyDirExtended recursively copies a directory tree, attempting to preserve permissions.
// Source directory must exist, destination directory must *not* exist. It ignores any files or
// directories that are given through the ignore parameter.
// Symlinks are ignored and skipped.
// Credit: https://gist.github.com/r0l1/92462b38df26839a3ca324697c8cba04
func CopyDirExtended(src string, dst string, ignore []string) (err error) {

    ignoreList := slicer.String(ignore)
    src = filepath.Clean(src)
    dst = filepath.Clean(dst)

    si, err := os.Stat(src)
    if err != nil {
        return err
    }
    if !si.IsDir() {
        return fmt.Errorf("source is not a directory")
    }

    _, err = os.Stat(dst)
    if err != nil && !os.IsNotExist(err) {
        return
    }
    if err == nil {
        return fmt.Errorf("destination already exists")
    }

    err = MkDirs(dst)
    if err != nil {
        return
    }

    entries, err := os.ReadDir(src)
    if err != nil {
        return
    }

    for _, entry := range entries {
        if ignoreList.Contains(entry.Name()) {
            continue
        }
        srcPath := filepath.Join(src, entry.Name())
        dstPath := filepath.Join(dst, entry.Name())

        if entry.IsDir() {
            err = CopyDir(srcPath, dstPath)
            if err != nil {
                return
            }
        } else {
            // Skip symlinks.
            if entry.Type()&os.ModeSymlink != 0 {
                continue
            }

            err = CopyFile(srcPath, dstPath)
            if err != nil {
                return
            }
        }
    }

    return
}

// MoveDirExtended recursively moves a directory tree, attempting to preserve permissions.
// Source directory must exist, destination directory must *not* exist. It ignores any files or
// directories that are given through the ignore parameter.
// Symlinks are ignored and skipped.
func MoveDirExtended(src string, dst string, ignore []string) (err error) {

    ignoreList := slicer.String(ignore)
    src = filepath.Clean(src)
    dst = filepath.Clean(dst)

    si, err := os.Stat(src)
    if err != nil {
        return err
    }
    if !si.IsDir() {
        return fmt.Errorf("source is not a directory")
    }

    _, err = os.Stat(dst)
    if err != nil && !os.IsNotExist(err) {
        return
    }
    if err == nil {
        return fmt.Errorf("destination already exists")
    }

    err = MkDirs(dst)
    if err != nil {
        return
    }

    entries, err := os.ReadDir(src)
    if err != nil {
        return
    }

    for _, entry := range entries {
        if ignoreList.Contains(entry.Name()) {
            continue
        }
        srcPath := filepath.Join(src, entry.Name())
        dstPath := filepath.Join(dst, entry.Name())

        // Skip symlinks.
        if entry.Type()&os.ModeSymlink != 0 {
            continue
        }

        err := os.Rename(srcPath, dstPath)
        if err != nil {
            return err
        }
    }

    return
}

func FindPathToFile(fsys fs.FS, file string) (string, error) {
    stat, _ := fs.Stat(fsys, file)
    if stat != nil {
        return ".", nil
    }
    var indexFiles slicer.StringSlicer
    err := fs.WalkDir(fsys, ".", func(path string, d fs.DirEntry, err error) error {
        if err != nil {
            return err
        }
        if strings.HasSuffix(path, file) {
            indexFiles.Add(path)
        }
        return nil
    })
    if err != nil {
        return "", err
    }

    if indexFiles.Length() > 1 {
        selected := indexFiles.AsSlice()[0]
        for _, f := range indexFiles.AsSlice() {
            if len(f) < len(selected) {
                selected = f
            }
        }
        path, _ := filepath.Split(selected)
        return path, nil
    }
    if indexFiles.Length() > 0 {
        path, _ := filepath.Split(indexFiles.AsSlice()[0])
        return path, nil
    }
    return "", fmt.Errorf("no index.html found")
}