Documentation
¶
Overview ¶
Package util provides utility functions for interacting with filesystems.
Index ¶
- Constants
- Variables
- func Atomic(path string, fn func(path string) error) error
- func CopyFile(source, sink string) error
- func CopyFileRangeTo(path string, offset, length int64, writer io.Writer) error
- func CopyFileTo(path string, writer io.Writer) error
- func Create(path string) (*os.File, error)
- func CreateFile(path string, flags int, mode os.FileMode) (*os.File, error)
- func DirExists(path string) (bool, error)
- func FileExists(path string) (bool, error)
- func FileSize(path string) (uint64, error)
- func Mkdir(path string, mode os.FileMode, parents, ignoreExists bool) error
- func OpenRandAccess(path string, start, end int64) (*os.File, error)
- func OpenSeqAccess(path string, start, end int64) (*os.File, error)
- func ReadIfProvided(path string) ([]byte, error)
- func ReadJSONFile(path string, data any) error
- func Remove(path string, ignoreNotExists bool) error
- func RemoveAll(path string) error
- func Sync(path string) error
- func Touch(path string) error
- func WriteAt(path string, data []byte, offset int64) error
- func WriteFile(path string, data []byte, mode os.FileMode) error
- func WriteJSONFile(path string, data any, mode os.FileMode) error
- func WriteTempFile(dir string, data []byte) (string, error)
- func WriteToFile(path string, reader io.Reader, mode os.FileMode) error
Constants ¶
const ( // DefaultFileMode represents the default file mode which will be used if a zero value file mode is provided for // operations which create new files. DefaultFileMode os.FileMode = 0o660 // DefaultDirMode represents the default file mode which will be used if a zero value file mode is provided for // operations which create new directories. DefaultDirMode os.FileMode = 0o770 )
Variables ¶
var ( // ErrNotFile is returned by 'FileExists' if a directory exists at the provided path. ErrNotFile = errors.New("not a file") // ErrNotDir is returned by 'DirExists' if a file exists at the provided path. ErrNotDir = errors.New("not a directory") )
Functions ¶
func Atomic ¶
Atomic will perform the provided function in an "atmoic" fashion. It's required that the provided function create the file at the given path if it doesn't already exist.
NOTE: This only works to the degree that the underlying operating system guarantees that renames are atomic.
func CopyFile ¶
CopyFile copies the source file to the sink file truncating it if it already exists.
NOTE: The sink file will be given the same permissions as the source file.
func CopyFileRangeTo ¶
CopyFileRangeTo is similar to 'CopyFileTo' but allows specifying an offset/length.
func CopyFileTo ¶
CopyFileTo copies all the data from the file at the provided path into the given writer.
func Create ¶
Create a new file at the provided path in read/write mode, any existing file will be truncated when opening.
func CreateFile ¶
CreateFile creates a new file (or truncates an existing one) at the provided path using the given flags/mode.
NOTE: If a zero value file mode is suppled, the default will be used.
func DirExists ¶
DirExists returns a boolean indicating whether a directory at the provided path exists.
func FileExists ¶
FileExists returns a boolean indicating whether a file at the provided path exists.
func Mkdir ¶
Mkdir creates a new directory with the provided mode and may optionally create all parent directories.
NOTE: If a zero value file mode is suppled, the default will be used.
func OpenRandAccess ¶
OpenRandAccess opens the provided file whilst advising the kernel that we'll be accessing the byte range from start to end with a random access pattern; this should decrease the pre-fetch amount and avoid bloating the page cache with data that we'll only be using once. If a zero start/end is provided kernels after 2.6.6 will treat this as "all the bytes through to the end of the file".
NOTE: This is advise to the kernel, the kernel provides no guarantees that it will honor/action the advise.
func OpenSeqAccess ¶
OpenSeqAccess opens the provided file whilst advising the kernel that we'll be accessing the byte range from start to end sequentially; this should increase the pre-fetch amount for this file. If a zero start/end is provided kernels after 2.6.6 will treat this as "all the bytes through to the end of the file".
NOTE: This is advise to the kernel, the kernel provides no guarantees that it will honor/action the advise.
func ReadIfProvided ¶
ReadIfProvided is the equvilent to 'os.ReadFile' but will return <nil>, <nil> if no path is provided.
func ReadJSONFile ¶
ReadJSONFile unmarshals data from the provided file into the given interface.
func Touch ¶
Touch is analogous to the unix 'touch' command, it updates the access/modified times of the file at the provided path creating it if it doesn't exist.
func WriteAt ¶
WriteAt writes data to the given offset in the file at the provided path.
NOTE: The file at the given path must already exist.
func WriteJSONFile ¶
WriteJSONFile marshals the provided interface and writes it to a file at the given path.
func WriteTempFile ¶
WriteTempFile writes out the provided data to a temporary file in the given directory (OS temporary directory if omitted) and returns the path to that file.
NOTE: It's the job of the caller to correctly handle cleaning up the file.
Types ¶
This section is empty.
Source Files