OverlayFile is the path to a text file in the OverlayJSON format. It is the value of the -overlay flag.
var OverlayFile string
func Glob(pattern string) (matches []string, err error)
Glob is like filepath.Glob but uses the overlay file system.
func Init(wd string) error
Init initializes the overlay, if one is being used.
func IsDir(path string) (bool, error)
IsDir returns true if path is a directory on disk or in the overlay.
func IsDirWithGoFiles(dir string) (bool, error)
IsDirWithGoFiles reports whether dir is a directory containing Go files either on disk or in the overlay.
func Lstat(path string) (fs.FileInfo, error)
Lstat implements a version of os.Lstat that operates on the overlay filesystem.
func Open(path string) (*os.File, error)
Open opens the file at or overlaid on the given path.
func OverlayPath(path string) (string, bool)
OverlayPath returns the path to the overlaid contents of the file, the empty string if the overlay deletes the file, or path itself if the file is not in the overlay, the file is a directory in the overlay, or there is no overlay. It returns true if the path is overlaid with a regular file or deleted, and false otherwise.
func ReadDir(dir string) ([]fs.FileInfo, error)
ReadDir provides a slice of fs.FileInfo entries corresponding to the overlaid files in the directory.
func ReadFile(path string) ([]byte, error)
ReadFile reads the file at or overlaid on the given path.
func Stat(path string) (fs.FileInfo, error)
Stat implements a version of os.Stat that operates on the overlay filesystem.
func Trace(op, path string)
Trace emits a trace event for the operation and file path to the trace log, but only when $GODEBUG contains gofsystrace=1. The traces are appended to the file named by the $GODEBUG setting gofsystracelog, or else standard error. For debugging, if the $GODEBUG setting gofsystracestack is non-empty, then trace events for paths matching that glob pattern (using path.Match) will be followed by a full stack trace.
func Walk(root string, walkFn filepath.WalkFunc) error
Walk walks the file tree rooted at root, calling walkFn for each file or directory in the tree, including root.
OverlayJSON is the format overlay files are expected to be in. The Replace map maps from overlaid paths to replacement paths: the Go command will forward all reads trying to open each overlaid path to its replacement path, or consider the overlaid path not to exist if the replacement path is empty.
type OverlayJSON struct {
Replace map[string]string
}