Files
moby/pkg/fileutils/fileutils.go
Sebastiaan van Stijn c93f18e0b8 pkg/fileutils: remove // import comments
These comments were added to enforce using the correct import path for
our packages ("github.com/docker/docker", not "github.com/moby/moby").
However, when working in go module mode (not GOPATH / vendor), they have
no effect, so their impact is limited.

Remove these imports in preparation of migrating our code to become an
actual go module.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2025-05-30 15:59:17 +02:00

76 lines
1.9 KiB
Go

package fileutils
import (
"fmt"
"io"
"os"
"path/filepath"
)
// CopyFile copies from src to dst until either EOF is reached
// on src or an error occurs. It verifies src exists and removes
// the dst if it exists.
func CopyFile(src, dst string) (int64, error) {
cleanSrc := filepath.Clean(src)
cleanDst := filepath.Clean(dst)
if cleanSrc == cleanDst {
return 0, nil
}
sf, err := os.Open(cleanSrc)
if err != nil {
return 0, err
}
defer sf.Close()
if err := os.Remove(cleanDst); err != nil && !os.IsNotExist(err) {
return 0, err
}
df, err := os.Create(cleanDst)
if err != nil {
return 0, err
}
defer df.Close()
return io.Copy(df, sf)
}
// ReadSymlinkedDirectory returns the target directory of a symlink.
// The target of the symbolic link may not be a file.
func ReadSymlinkedDirectory(path string) (realPath string, _ error) {
var err error
realPath, err = filepath.Abs(path)
if err != nil {
return "", fmt.Errorf("unable to get absolute path for %s: %w", path, err)
}
realPath, err = filepath.EvalSymlinks(realPath)
if err != nil {
return "", fmt.Errorf("failed to canonicalise path for %s: %w", path, err)
}
realPathInfo, err := os.Stat(realPath)
if err != nil {
return "", fmt.Errorf("failed to stat target '%s' of '%s': %w", realPath, path, err)
}
if !realPathInfo.Mode().IsDir() {
return "", fmt.Errorf("canonical path points to a file '%s'", realPath)
}
return realPath, nil
}
// CreateIfNotExists creates a file or a directory only if it does not already exist.
func CreateIfNotExists(path string, isDir bool) error {
if _, err := os.Stat(path); err != nil {
if os.IsNotExist(err) {
if isDir {
return os.MkdirAll(path, 0o755)
}
if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
return err
}
f, err := os.OpenFile(path, os.O_CREATE, 0o755)
if err != nil {
return err
}
_ = f.Close()
}
}
return nil
}