directory-1.3.8.5: Platform-agnostic library for filesystem operations

Copyright | (c) The University of Glasgow 2001
License | BSD-style (see the file libraries/base/LICENSE)
Maintainer | libraries@haskell.org
Stability | stable
Portability | portable
Safe Haskell | None
Language | Haskell2010

System.Directory

Contents

- Actions on directories
  - Current working directory
- Pre-defined directories
- Actions on files
- Existence tests
- Symbolic links
- Permissions
- Timestamps
- Deprecated

Description

System-independent interface to directory manipulation (FilePath API).

Synopsis

- createDirectory :: FilePath -> IO ()
- createDirectoryIfMissing :: Bool -> FilePath -> IO ()
- removeDirectory :: FilePath -> IO ()
- removeDirectoryRecursive :: FilePath -> IO ()
- removePathForcibly :: FilePath -> IO ()
- renameDirectory :: FilePath -> FilePath -> IO ()
- listDirectory :: FilePath -> IO [FilePath]
- getDirectoryContents :: FilePath -> IO [FilePath]
- getCurrentDirectory :: IO FilePath
- setCurrentDirectory :: FilePath -> IO ()
- withCurrentDirectory :: FilePath -> IO a -> IO a
- getHomeDirectory :: IO FilePath
- data XdgDirectory
  - = XdgData
  - | XdgConfig
  - | XdgCache
  - | XdgState
- getXdgDirectory :: XdgDirectory -> FilePath -> IO FilePath
- data XdgDirectoryList
  - = XdgDataDirs
  - | XdgConfigDirs
- getXdgDirectoryList :: XdgDirectoryList -> IO [FilePath]
- getAppUserDataDirectory :: FilePath -> IO FilePath
- getUserDocumentsDirectory :: IO FilePath
- getTemporaryDirectory :: IO FilePath
- removeFile :: FilePath -> IO ()
- renameFile :: FilePath -> FilePath -> IO ()
- renamePath :: FilePath -> FilePath -> IO ()
- copyFile :: FilePath -> FilePath -> IO ()
- copyFileWithMetadata :: FilePath -> FilePath -> IO ()
- getFileSize :: FilePath -> IO Integer
- canonicalizePath :: FilePath -> IO FilePath
- makeAbsolute :: FilePath -> IO FilePath
- makeRelativeToCurrentDirectory :: FilePath -> IO FilePath
- doesPathExist :: FilePath -> IO Bool
- doesFileExist :: FilePath -> IO Bool
- doesDirectoryExist :: FilePath -> IO Bool
- findExecutable :: String -> IO (Maybe FilePath)
- findExecutables :: String -> IO [FilePath]
- findExecutablesInDirectories :: [FilePath] -> String -> IO [FilePath]
- findFile :: [FilePath] -> String -> IO (Maybe FilePath)
- findFiles :: [FilePath] -> String -> IO [FilePath]
- findFileWith :: (FilePath -> IO Bool) -> [FilePath] -> String -> IO (Maybe FilePath)
- findFilesWith :: (FilePath -> IO Bool) -> [FilePath] -> String -> IO [FilePath]
- exeExtension :: String
- createFileLink :: FilePath -> FilePath -> IO ()
- createDirectoryLink :: FilePath -> FilePath -> IO ()
- removeDirectoryLink :: FilePath -> IO ()
- pathIsSymbolicLink :: FilePath -> IO Bool
- getSymbolicLinkTarget :: FilePath -> IO FilePath
- data Permissions
- emptyPermissions :: Permissions
- readable :: Permissions -> Bool
- writable :: Permissions -> Bool
- executable :: Permissions -> Bool
- searchable :: Permissions -> Bool
- setOwnerReadable :: Bool -> Permissions -> Permissions
- setOwnerWritable :: Bool -> Permissions -> Permissions
- setOwnerExecutable :: Bool -> Permissions -> Permissions
- setOwnerSearchable :: Bool -> Permissions -> Permissions
- getPermissions :: FilePath -> IO Permissions
- setPermissions :: FilePath -> Permissions -> IO ()
- copyPermissions :: FilePath -> FilePath -> IO ()
- getAccessTime :: FilePath -> IO UTCTime
- getModificationTime :: FilePath -> IO UTCTime
- setAccessTime :: FilePath -> UTCTime -> IO ()
- setModificationTime :: FilePath -> UTCTime -> IO ()
- isSymbolicLink :: FilePath -> IO Bool

# Documentation

A directory contains a series of entries, each of which is a named reference to a file system object (file, directory etc.). Some entries may be hidden, inaccessible, or have some administrative function (e.g. `.` or `..` under POSIX), but in this standard all such entries are considered to form part of the directory contents. Entries in sub-directories are not, however, considered to form part of the directory contents.

Each file system object is referenced by a path. There is normally at least one absolute path to each file system object. In some operating systems, it may also be possible to have paths which are relative to the current directory.

Unless otherwise documented:

- `IO` operations in this package may throw any `IOError`. No other types of exceptions shall be thrown.
- The list of possible `IOErrorType`s in the API documentation is not exhaustive. The full list may vary by platform and/or evolve over time.

# Actions on directories

createDirectory :: FilePath -> IO () Source #

``createDirectory` dir` creates a new directory `dir` which is initially empty, or as near to empty as the operating system allows.

The operation may fail with:

- `isPermissionError` The process has insufficient privileges to perform the operation. `[EROFS, EACCES]`
- `isAlreadyExistsError` The operand refers to a directory that already exists. `[EEXIST]`
- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` The operand is not a valid directory name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` There is no path to the directory. `[ENOENT, ENOTDIR]`
- `isFullError` Insufficient resources (virtual memory, process file descriptors, physical disk space, etc.) are available to perform the operation. `[EDQUOT, ENOSPC, ENOMEM, EMLINK]`
- `InappropriateType` The path refers to an existing non-directory object. `[EEXIST]`

createDirectoryIfMissing Source #

Arguments

:: Bool | Create its parents too?
-> FilePath | The path to the directory you want to make
-> IO () |

``createDirectoryIfMissing` parents dir` creates a new directory `dir` if it doesn't exist. If the first argument is `True` the function will also create all parent directories if they are missing.

removeDirectory :: FilePath -> IO () Source #

``removeDirectory` dir` removes an existing directory dir. The implementation may specify additional constraints which must be satisfied before a directory can be removed (e.g. the directory has to be empty, or may not be in use by other processes). It is not legal for an implementation to partially remove a directory unless the entire directory is removed. A conformant implementation need not support directory removal in all situations (e.g. removal of the root directory).

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` The operand is not a valid directory name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The directory does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `UnsatisfiedConstraints` Implementation-dependent constraints are not satisfied. `[EBUSY, ENOTEMPTY, EEXIST]`
- `UnsupportedOperation` The implementation does not support removal in this situation. `[EINVAL]`
- `InappropriateType` The operand refers to an existing non-directory object. `[ENOTDIR]`

removeDirectoryRecursive :: FilePath -> IO () Source #

``removeDirectoryRecursive` dir` removes an existing directory dir together with its contents and subdirectories. Within this directory, symbolic links are removed without affecting their targets.

On Windows, the operation fails if dir is a directory symbolic link.

This operation is reported to be flaky on Windows so retry logic may be advisable. See: https://github.com/haskell/directory/pull/108

removePathForcibly :: FilePath -> IO () Source #

Removes a file or directory at path together with its contents and subdirectories. Symbolic links are removed without affecting their targets. If the path does not exist, nothing happens.

Unlike other removal functions, this function will also attempt to delete files marked as read-only or otherwise made unremovable due to permissions. As a result, if the removal is incomplete, the permissions or attributes on the remaining files may be altered. If there are hard links in the directory, then permissions on all related hard links may be altered.

If an entry within the directory vanishes while `removePathForcibly` is running, it is silently ignored.

If an exception occurs while removing an entry, `removePathForcibly` will still try to remove as many entries as it can before failing with an exception. The first exception that it encountered is re-thrown.

Since: directory-1.2.7.0

renameDirectory :: FilePath -> FilePath -> IO () Source #

``renameDirectory` old new` changes the name of an existing directory from old to new. If the new directory already exists, it is atomically replaced by the old directory. If the new directory is neither the old directory nor an alias of the old directory, it is removed as if by `removeDirectory`. A conformant implementation need not support renaming directories in all situations (e.g. renaming to an existing directory, or across different physical devices), but the constraints must be documented.

On Win32 platforms, `renameDirectory` fails if the new directory already exists.

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` Either operand is not a valid directory name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The original directory does not exist, or there is no path to the target. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `isFullError` Insufficient resources are available to perform the operation. `[EDQUOT, ENOSPC, ENOMEM, EMLINK]`
- `UnsatisfiedConstraints` Implementation-dependent constraints are not satisfied. `[EBUSY, ENOTEMPTY, EEXIST]`
- `UnsupportedOperation` The implementation does not support renaming in this situation. `[EINVAL, EXDEV]`
- `InappropriateType` Either path refers to an existing non-directory object. `[ENOTDIR, EISDIR]`

listDirectory :: FilePath -> IO [FilePath] Source #

``listDirectory` dir` returns a list of all entries in dir without the special entries (`.` and `..`).

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` The operand is not a valid directory name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The directory does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EACCES]`
- `isFullError` Insufficient resources are available to perform the operation. `[EMFILE, ENFILE]`
- `InappropriateType` The path refers to an existing non-directory object. `[ENOTDIR]`

Since: directory-1.2.5.0

getDirectoryContents :: FilePath -> IO [FilePath] Source #

Similar to `listDirectory`, but always includes the special entries (`.` and `..`). (This applies to Windows as well.)

The operation may fail with the same exceptions as `listDirectory`.

## Current working directory

getCurrentDirectory :: IO FilePath Source #

Obtain the current working directory as an absolute path.

In a multithreaded program, the current working directory is a global state shared among all threads of the process. Therefore, when performing filesystem operations from multiple threads, it is highly recommended to use absolute rather than relative paths (see: `makeAbsolute`).

Note that `getCurrentDirectory` is not guaranteed to return the same path received by `setCurrentDirectory`. On POSIX systems, the path returned will always be fully dereferenced (not contain any symbolic links). For more information, refer to the documentation of getcwd.

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `isDoesNotExistError` There is no path referring to the working directory. `[EPERM, ENOENT, ESTALE...]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EACCES]`
- `isFullError` Insufficient resources are available to perform the operation.
- `UnsupportedOperation` The operating system has no notion of current working directory.

setCurrentDirectory :: FilePath -> IO () Source #

Change the working directory to the given path.

In a multithreaded program, the current working directory is a global state shared among all threads of the process. Therefore, when performing filesystem operations from multiple threads, it is highly recommended to use absolute rather than relative paths (see: `makeAbsolute`).

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` The operand is not a valid directory name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The directory does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EACCES]`
- `UnsupportedOperation` The operating system has no notion of current working directory, or the working directory cannot be dynamically changed.
- `InappropriateType` The path refers to an existing non-directory object. `[ENOTDIR]`

withCurrentDirectory Source #

Arguments

:: FilePath | Directory to execute in
-> IO a | Action to be executed
-> IO a |

Run an `IO` action with the given working directory and restore the original working directory afterwards, even if the given action fails due to an exception.

The operation may fail with the same exceptions as `getCurrentDirectory` and `setCurrentDirectory`.

Since: directory-1.2.3.0

# Pre-defined directories

getHomeDirectory :: IO FilePath Source #

Returns the current user's home directory.

The directory returned is expected to be writable by the current user, but note that it isn't generally considered good practice to store application-specific data here; use `getXdgDirectory` or `getAppUserDataDirectory` instead.

On Unix, `getHomeDirectory` behaves as follows:

- Returns $HOME env variable if set (including to an empty string).
- Otherwise uses home directory returned by `getpwuid_r` using the UID of the current proccesses user. This basically reads the etcpasswd file. An empty home directory field is considered valid.

On Windows, the system is queried for a suitable path; a typical path might be `C:/Users/<user>`.

The operation may fail with:

- `UnsupportedOperation` The operating system has no notion of home directory.
- `isDoesNotExistError` The home directory for the current user does not exist, or cannot be found.

data XdgDirectory Source #

Special directories for storing user-specific application data, configuration, and cache files, as specified by the XDG Base Directory Specification.

Note: On Windows, `XdgData` and `XdgConfig` usually map to the same directory.

Since: directory-1.2.3.0

Constructors

XdgData | For data files (e.g. images). It uses the `XDG_DATA_HOME` environment variable. On non-Windows systems, the default is `~/.local/share`. On Windows, the default is `%APPDATA%` (e.g. `C:/Users/<user>/AppData/Roaming`). Can be considered as the user-specific equivalent of `/usr/share`.
XdgConfig | For configuration files. It uses the `XDG_CONFIG_HOME` environment variable. On non-Windows systems, the default is `~/.config`. On Windows, the default is `%APPDATA%` (e.g. `C:/Users/<user>/AppData/Roaming`). Can be considered as the user-specific equivalent of `/etc`.
XdgCache | For non-essential files (e.g. cache). It uses the `XDG_CACHE_HOME` environment variable. On non-Windows systems, the default is `~/.cache`. On Windows, the default is `%LOCALAPPDATA%` (e.g. `C:/Users/<user>/AppData/Local`). Can be considered as the user-specific equivalent of `/var/cache`.
XdgState | For data that should persist between (application) restarts, but that is not important or portable enough to the user that it should be stored in `XdgData`. It uses the `XDG_STATE_HOME` environment variable. On non-Windows sytems, the default is `~/.local/state`. On Windows, the default is `%LOCALAPPDATA%` (e.g. `C:/Users/<user>/AppData/Local`). Since: directory-1.3.7.0

#### Instances

Instances details

Bounded XdgDirectory Source # |
Instance details Defined in System.Directory.Internal.Common Methods minBound :: XdgDirectory # maxBound :: XdgDirectory #
Enum XdgDirectory Source # |

Instance details

Defined in System.Directory.Internal.Common

Methods

succ :: XdgDirectory -> XdgDirectory #

pred :: XdgDirectory -> XdgDirectory #

toEnum :: Int -> XdgDirectory #

fromEnum :: XdgDirectory -> Int #

enumFrom :: XdgDirectory -> [XdgDirectory] #

enumFromThen :: XdgDirectory -> XdgDirectory -> [XdgDirectory] #

enumFromTo :: XdgDirectory -> XdgDirectory -> [XdgDirectory] #

enumFromThenTo :: XdgDirectory -> XdgDirectory -> XdgDirectory -> [XdgDirectory] #

Read XdgDirectory Source # |
Instance details Defined in System.Directory.Internal.Common Methods readsPrec :: Int -> ReadS XdgDirectory # readList :: ReadS [XdgDirectory] # readPrec :: ReadPrec XdgDirectory # readListPrec :: ReadPrec [XdgDirectory] #
Show XdgDirectory Source # |
Instance details Defined in System.Directory.Internal.Common Methods showsPrec :: Int -> XdgDirectory -> ShowS # show :: XdgDirectory -> String # showList :: [XdgDirectory] -> ShowS #
Eq XdgDirectory Source # |
Instance details Defined in System.Directory.Internal.Common Methods (==) :: XdgDirectory -> XdgDirectory -> Bool # (/=) :: XdgDirectory -> XdgDirectory -> Bool #
Ord XdgDirectory Source # |

Instance details

Defined in System.Directory.Internal.Common

Methods

compare :: XdgDirectory -> XdgDirectory -> Ordering #

(<) :: XdgDirectory -> XdgDirectory -> Bool #

(<=) :: XdgDirectory -> XdgDirectory -> Bool #

(>) :: XdgDirectory -> XdgDirectory -> Bool #

(>=) :: XdgDirectory -> XdgDirectory -> Bool #

max :: XdgDirectory -> XdgDirectory -> XdgDirectory #

min :: XdgDirectory -> XdgDirectory -> XdgDirectory #

getXdgDirectory Source #

Arguments

:: XdgDirectory | which special directory
-> FilePath | a relative path that is appended to the path; if empty, the base path is returned
-> IO FilePath |

Obtain the paths to special directories for storing user-specific application data, configuration, and cache files, conforming to the XDG Base Directory Specification. Compared with `getAppUserDataDirectory`, this function provides a more fine-grained hierarchy as well as greater flexibility for the user.

On Windows, `XdgData` and `XdgConfig` usually map to the same directory unless overridden.

Refer to the docs of `XdgDirectory` for more details.

The second argument is usually the name of the application. Since it will be integrated into the path, it must consist of valid path characters. Note: if the second argument is an absolute path, it will just return the second argument.

Note: The directory may not actually exist, in which case you would need to create it with file mode `700` (i.e. only accessible by the owner).

As of 1.3.5.0, the environment variable is ignored if set to a relative path, per revised XDG Base Directory Specification. See #100.

Since: directory-1.2.3.0

data XdgDirectoryList Source #

Search paths for various application data, as specified by the XDG Base Directory Specification.

The list of paths is split using `searchPathSeparator`, which on Windows is a semicolon.

Note: On Windows, `XdgDataDirs` and `XdgConfigDirs` usually yield the same result.

Since: directory-1.3.2.0

Constructors

XdgDataDirs | For data files (e.g. images). It uses the `XDG_DATA_DIRS` environment variable. On non-Windows systems, the default is `/usr/local/share/` and `/usr/share/`. On Windows, the default is `%PROGRAMDATA%` or `%ALLUSERSPROFILE%` (e.g. `C:/ProgramData`).
XdgConfigDirs | For configuration files. It uses the `XDG_CONFIG_DIRS` environment variable. On non-Windows systems, the default is `/etc/xdg`. On Windows, the default is `%PROGRAMDATA%` or `%ALLUSERSPROFILE%` (e.g. `C:/ProgramData`).

#### Instances

Instances details

Bounded XdgDirectoryList Source # |
Instance details Defined in System.Directory.Internal.Common Methods minBound :: XdgDirectoryList # maxBound :: XdgDirectoryList #
Enum XdgDirectoryList Source # |

Instance details

Defined in System.Directory.Internal.Common

Methods

succ :: XdgDirectoryList -> XdgDirectoryList #

pred :: XdgDirectoryList -> XdgDirectoryList #

toEnum :: Int -> XdgDirectoryList #

fromEnum :: XdgDirectoryList -> Int #

enumFrom :: XdgDirectoryList -> [XdgDirectoryList] #

enumFromThen :: XdgDirectoryList -> XdgDirectoryList -> [XdgDirectoryList] #

enumFromTo :: XdgDirectoryList -> XdgDirectoryList -> [XdgDirectoryList] #

enumFromThenTo :: XdgDirectoryList -> XdgDirectoryList -> XdgDirectoryList -> [XdgDirectoryList] #

Read XdgDirectoryList Source # |
Instance details Defined in System.Directory.Internal.Common Methods readsPrec :: Int -> ReadS XdgDirectoryList # readList :: ReadS [XdgDirectoryList] # readPrec :: ReadPrec XdgDirectoryList # readListPrec :: ReadPrec [XdgDirectoryList] #
Show XdgDirectoryList Source # |
Instance details Defined in System.Directory.Internal.Common Methods showsPrec :: Int -> XdgDirectoryList -> ShowS # show :: XdgDirectoryList -> String # showList :: [XdgDirectoryList] -> ShowS #
Eq XdgDirectoryList Source # |
Instance details Defined in System.Directory.Internal.Common Methods (==) :: XdgDirectoryList -> XdgDirectoryList -> Bool # (/=) :: XdgDirectoryList -> XdgDirectoryList -> Bool #
Ord XdgDirectoryList Source # |

Instance details

Defined in System.Directory.Internal.Common

Methods

compare :: XdgDirectoryList -> XdgDirectoryList -> Ordering #

(<) :: XdgDirectoryList -> XdgDirectoryList -> Bool #

(<=) :: XdgDirectoryList -> XdgDirectoryList -> Bool #

(>) :: XdgDirectoryList -> XdgDirectoryList -> Bool #

(>=) :: XdgDirectoryList -> XdgDirectoryList -> Bool #

max :: XdgDirectoryList -> XdgDirectoryList -> XdgDirectoryList #

min :: XdgDirectoryList -> XdgDirectoryList -> XdgDirectoryList #

getXdgDirectoryList Source #

Arguments

:: XdgDirectoryList | which special directory list
-> IO [FilePath] |

Similar to `getXdgDirectory` but retrieves the entire list of XDG directories.

On Windows, `XdgDataDirs` and `XdgConfigDirs` usually map to the same list of directories unless overridden.

Refer to the docs of `XdgDirectoryList` for more details.

getAppUserDataDirectory Source #

Arguments

:: FilePath | a relative path that is appended to the path
-> IO FilePath |

Obtain the path to a special directory for storing user-specific application data (traditional Unix location). Newer applications may prefer the the XDG-conformant location provided by `getXdgDirectory` (migration guide).

The argument is usually the name of the application. Since it will be integrated into the path, it must consist of valid path characters.

- On Unix-like systems, the path is `~/.<app>`.
- On Windows, the path is `%APPDATA%/<app>` (e.g. `C:/Users/<user>/AppData/Roaming/<app>`)

Note: the directory may not actually exist, in which case you would need to create it. It is expected that the parent directory exists and is writable.

The operation may fail with:

- `UnsupportedOperation` The operating system has no notion of application-specific data directory.
- `isDoesNotExistError` The home directory for the current user does not exist, or cannot be found.

getUserDocumentsDirectory :: IO FilePath Source #

Returns the current user's document directory.

The directory returned is expected to be writable by the current user, but note that it isn't generally considered good practice to store application-specific data here; use `getXdgDirectory` or `getAppUserDataDirectory` instead.

On Unix, `getUserDocumentsDirectory` returns the value of the `HOME` environment variable. On Windows, the system is queried for a suitable path; a typical path might be `C:/Users/<user>/Documents`.

The operation may fail with:

- `UnsupportedOperation` The operating system has no notion of document directory.
- `isDoesNotExistError` The document directory for the current user does not exist, or cannot be found.

getTemporaryDirectory :: IO FilePath Source #

Returns the current directory for temporary files.

On Unix, `getTemporaryDirectory` returns the value of the `TMPDIR` environment variable or "/tmp" if the variable isn't defined. On Windows, the function checks for the existence of environment variables in the following order and uses the first path found:

- TMP environment variable.
- TEMP environment variable.
- USERPROFILE environment variable.
- The Windows directory

The operation may fail with:

- `UnsupportedOperation` The operating system has no notion of temporary directory.

The function doesn't verify whether the path exists.

# Actions on files

removeFile :: FilePath -> IO () Source #

`removeFile` file removes the directory entry for an existing file file, where file is not itself a directory. The implementation may specify additional constraints which must be satisfied before a file can be removed (e.g. the file may not be in use by other processes).

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` The operand is not a valid file name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The file does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `UnsatisfiedConstraints` Implementation-dependent constraints are not satisfied. `[EBUSY]`
- `InappropriateType` The operand refers to an existing directory. `[EPERM, EINVAL]`

renameFile :: FilePath -> FilePath -> IO () Source #

``renameFile` old new` changes the name of an existing file system object from old to new. If the new object already exists, it is replaced by the old object. Neither path may refer to an existing directory.

A conformant implementation need not support renaming files in all situations (e.g. renaming across different physical devices), but the constraints must be documented. On Windows, this does not support renaming across different physical devices; if you are looking to do so, consider using `copyFileWithMetadata` and `removeFile`.

On Windows, this calls `MoveFileEx` with `MOVEFILE_REPLACE_EXISTING` set, which is not guaranteed to be atomic (https://github.com/haskell/directory/issues/109).

On other platforms, this operation is atomic.

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` Either operand is not a valid file name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The original file does not exist, or there is no path to the target. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `isFullError` Insufficient resources are available to perform the operation. `[EDQUOT, ENOSPC, ENOMEM, EMLINK]`
- `UnsatisfiedConstraints` Implementation-dependent constraints are not satisfied. `[EBUSY]`
- `UnsupportedOperation` The implementation does not support renaming in this situation. `[EXDEV]`
- `InappropriateType` Either path refers to an existing directory. `[ENOTDIR, EISDIR, EINVAL, EEXIST, ENOTEMPTY]`

renamePath Source #

Arguments

:: FilePath | Old path
-> FilePath | New path
-> IO () |

Rename a file or directory. If the destination path already exists, it is replaced atomically. The destination path must not point to an existing directory. A conformant implementation need not support renaming files in all situations (e.g. renaming across different physical devices), but the constraints must be documented.

The operation may fail with:

- `HardwareFault` A physical I/O error has occurred. `[EIO]`
- `InvalidArgument` Either operand is not a valid file name. `[ENAMETOOLONG, ELOOP]`
- `isDoesNotExistError` The original file does not exist, or there is no path to the target. `[ENOENT, ENOTDIR]`
- `isPermissionError` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `isFullError` Insufficient resources are available to perform the operation. `[EDQUOT, ENOSPC, ENOMEM, EMLINK]`
- `UnsatisfiedConstraints` Implementation-dependent constraints are not satisfied. `[EBUSY]`
- `UnsupportedOperation` The implementation does not support renaming in this situation. `[EXDEV]`
- `InappropriateType` Either the destination path refers to an existing directory, or one of the parent segments in the destination path is not a directory. `[ENOTDIR, EISDIR, EINVAL, EEXIST, ENOTEMPTY]`

Since: directory-1.2.7.0

copyFile Source #

Arguments

:: FilePath | Source filename
-> FilePath | Destination filename
-> IO () |

Copy a file with its permissions. If the destination file already exists, it is replaced atomically. Neither path may refer to an existing directory. No exceptions are thrown if the permissions could not be copied.

copyFileWithMetadata Source #

Arguments

:: FilePath | Source file
-> FilePath | Destination file
-> IO () |

Copy a file with its associated metadata. If the destination file already exists, it is overwritten. There is no guarantee of atomicity in the replacement of the destination file. Neither path may refer to an existing directory. If the source and/or destination are symbolic links, the copy is performed on the targets of the links.

On Windows, it behaves like the Win32 function CopyFile, which copies various kinds of metadata including file attributes and security resource properties.

On Unix-like systems, permissions, access time, and modification time are preserved. If possible, the owner and group are also preserved. Note that the very act of copying can change the access time of the source file, hence the access times of the two files may differ after the operation completes.

Since: directory-1.2.6.0

getFileSize :: FilePath -> IO Integer Source #

Obtain the size of a file in bytes.

Since: directory-1.2.7.0

canonicalizePath :: FilePath -> IO FilePath Source #

Make a path absolute, normalize the path, and remove as many indirections from it as possible. Any trailing path separators are discarded via `dropTrailingPathSeparator`. Additionally, on Windows the letter case of the path is canonicalized.

Note: This function is a very big hammer. If you only need an absolute path, `makeAbsolute` is sufficient for removing dependence on the current working directory.

Indirections include the two special directories `.` and `..`, as well as any symbolic links (and junction points on Windows). The input path need not point to an existing file or directory. Canonicalization is performed on the longest prefix of the path that points to an existing file or directory. The remaining portion of the path that does not point to an existing file or directory will still be normalized, but case canonicalization and indirection removal are skipped as they are impossible to do on a nonexistent path.

Most programs should not worry about the canonicity of a path. In particular, despite the name, the function does not truly guarantee canonicity of the returned path due to the presence of hard links, mount points, etc.

If the path points to an existing file or directory, then the output path shall also point to the same file or directory, subject to the condition that the relevant parts of the file system do not change while the function is still running. In other words, the function is definitively not atomic. The results can be utterly wrong if the portions of the path change while this function is running.

Since some indirections (symbolic links on all systems, `..` on non-Windows systems, and junction points on Windows) are dependent on the state of the existing filesystem, the function can only make a conservative attempt by removing such indirections from the longest prefix of the path that still points to an existing file or directory.

Note that on Windows parent directories `..` are always fully expanded before the symbolic links, as consistent with the rest of the Windows API (such as `GetFullPathName`). In contrast, on POSIX systems parent directories `..` are expanded alongside symbolic links from left to right. To put this more concretely: if `L` is a symbolic link for `R/P`, then on Windows `L\..` refers to `.`, whereas on other operating systems `L/..` refers to `R`.

Similar to `normalise`, passing an empty path is equivalent to passing the current directory.

`canonicalizePath` can resolve at least 64 indirections in a single path, more than what is supported by most operating systems. Therefore, it may return the fully resolved path even though the operating system itself would have long given up.

On Windows XP or earlier systems, junction expansion is not performed due to their lack of `GetFinalPathNameByHandle`.

Changes since 1.2.3.0: The function has been altered to be more robust and has the same exception behavior as `makeAbsolute`.

Changes since 1.3.0.0: The function no longer preserves the trailing path separator. File symbolic links that appear in the middle of a path are properly dereferenced. Case canonicalization and symbolic link expansion are now performed on Windows.

makeAbsolute :: FilePath -> IO FilePath Source #

Convert a path into an absolute path. If the given path is relative, the current directory is prepended and then the combined result is normalized. If the path is already absolute, the path is simply normalized. The function preserves the presence or absence of the trailing path separator unless the path refers to the root directory `/`.

If the path is already absolute, the operation never fails. Otherwise, the operation may fail with the same exceptions as `getCurrentDirectory`.

Since: directory-1.2.2.0

makeRelativeToCurrentDirectory :: FilePath -> IO FilePath Source #

Construct a path relative to the current directory, similar to `makeRelative`.

The operation may fail with the same exceptions as `getCurrentDirectory`.

# Existence tests

doesPathExist :: FilePath -> IO Bool Source #

Test whether the given path points to an existing filesystem object. If the user lacks necessary permissions to search the parent directories, this function may return false even if the file does actually exist.

Since: directory-1.2.7.0

doesFileExist :: FilePath -> IO Bool Source #

The operation `doesFileExist` returns `True` if the argument file exists and is not a directory, and `False` otherwise.

doesDirectoryExist :: FilePath -> IO Bool Source #

The operation `doesDirectoryExist` returns `True` if the argument file exists and is either a directory or a symbolic link to a directory, and `False` otherwise.

findExecutable :: String -> IO (Maybe FilePath) Source #

Given the name or path of an executable file, `findExecutable` searches for such a file in a list of system-defined locations, which generally includes `PATH` and possibly more. The full path to the executable is returned if found. For example, `(findExecutable "ghc")` would normally give you the path to GHC.

The path returned by ``findExecutable` name` corresponds to the program that would be executed by `createProcess` when passed the same string (as a `RawCommand`, not a `ShellCommand`), provided that `name` is not a relative path with more than one segment.

On Windows, `findExecutable` calls the Win32 function `SearchPath`, which may search other places before checking the directories in the `PATH` environment variable. Where it actually searches depends on registry settings, but notably includes the directory containing the current executable.

On non-Windows platforms, the behavior is equivalent to `findFileWith` using the search directories from the `PATH` environment variable and testing each file for executable permissions. Details can be found in the documentation of `findFileWith`.

findExecutables :: String -> IO [FilePath] Source #

Search for executable files in a list of system-defined locations, which generally includes `PATH` and possibly more.

On Windows, this only returns the first occurrence, if any. Its behavior is therefore equivalent to `findExecutable`.

On non-Windows platforms, the behavior is equivalent to `findExecutablesInDirectories` using the search directories from the `PATH` environment variable. Details can be found in the documentation of `findExecutablesInDirectories`.

Since: directory-1.2.2.0

findExecutablesInDirectories :: [FilePath] -> String -> IO [FilePath] Source #

Given a name or path, `findExecutable` appends the `exeExtension` to the query and searches for executable files in the list of given search directories and returns all occurrences.

The behavior is equivalent to `findFileWith` using the given search directories and testing each file for executable permissions. Details can be found in the documentation of `findFileWith`.

Unlike other similarly named functions, `findExecutablesInDirectories` does not use `SearchPath` from the Win32 API. The behavior of this function on Windows is therefore equivalent to those on non-Windows platforms.

Since: directory-1.2.4.0

findFile :: [FilePath] -> String -> IO (Maybe FilePath) Source #

Search through the given list of directories for the given file.

The behavior is equivalent to `findFileWith`, returning only the first occurrence. Details can be found in the documentation of `findFileWith`.

findFiles :: [FilePath] -> String -> IO [FilePath] Source #

Search through the given list of directories for the given file and returns all paths where the given file exists.

The behavior is equivalent to `findFilesWith`. Details can be found in the documentation of `findFilesWith`.

Since: directory-1.2.1.0

findFileWith :: (FilePath -> IO Bool) -> [FilePath] -> String -> IO (Maybe FilePath) Source #

Search through a given list of directories for a file that has the given name and satisfies the given predicate and return the path of the first occurrence. The directories are checked in a left-to-right order.

This is essentially a more performant version of `findFilesWith` that always returns the first result, if any. Details can be found in the documentation of `findFilesWith`.

Since: directory-1.2.6.0

findFilesWith :: (FilePath -> IO Bool) -> [FilePath] -> String -> IO [FilePath] Source #

`findFilesWith predicate dirs name` searches through the list of directories (`dirs`) for files that have the given `name` and satisfy the given `predicate` and returns the paths of those files. The directories are checked in a left-to-right order and the paths are returned in the same order.

If the `name` is a relative path, then for every search directory `dir`, the function checks whether `dir `</>` name` exists and satisfies the predicate. If so, `dir `</>` name` is returned as one of the results. In other words, the returned paths can be either relative or absolute depending on the search directories were used. If there are no search directories, no results are ever returned.

If the `name` is an absolute path, then the function will return a single result if the file exists and satisfies the predicate and no results otherwise. This is irrespective of what search directories were given.

Since: directory-1.2.1.0

exeExtension :: String Source #

Filename extension for executable files (including the dot if any) (usually `""` on POSIX systems and `".exe"` on Windows or OS/2).

Since: directory-1.2.4.0

# Symbolic links

createFileLink Source #

Arguments

:: FilePath | path to the target file
-> FilePath | path of the link to be created
-> IO () |

Create a file symbolic link. The target path can be either absolute or relative and need not refer to an existing file. The order of arguments follows the POSIX convention.

To remove an existing file symbolic link, use `removeFile`.

Although the distinction between file symbolic links and directory symbolic links does not exist on POSIX systems, on Windows this is an intrinsic property of every symbolic link and cannot be changed without recreating the link. A file symbolic link that actually points to a directory will fail to dereference and vice versa. Moreover, creating symbolic links on Windows may require privileges unavailable to users outside the Administrators group. Portable programs that use symbolic links should take both into consideration.

On Windows, the function is implemented using `CreateSymbolicLink`. Since 1.3.3.0, the `SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE` flag is included if supported by the operating system. On POSIX, the function uses `symlink` and is therefore atomic.

Windows-specific errors: This operation may fail with `permissionErrorType` if the user lacks the privileges to create symbolic links. It may also fail with `illegalOperationErrorType` if the file system does not support symbolic links.

Since: directory-1.3.1.0

createDirectoryLink Source #

Arguments

:: FilePath | path to the target directory
-> FilePath | path of the link to be created
-> IO () |

Create a directory symbolic link. The target path can be either absolute or relative and need not refer to an existing directory. The order of arguments follows the POSIX convention.

To remove an existing directory symbolic link, use `removeDirectoryLink`.

Although the distinction between file symbolic links and directory symbolic links does not exist on POSIX systems, on Windows this is an intrinsic property of every symbolic link and cannot be changed without recreating the link. A file symbolic link that actually points to a directory will fail to dereference and vice versa. Moreover, creating symbolic links on Windows may require privileges unavailable to users outside the Administrators group. Portable programs that use symbolic links should take both into consideration.

On Windows, the function is implemented using `CreateSymbolicLink` with `SYMBOLIC_LINK_FLAG_DIRECTORY`. Since 1.3.3.0, the `SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE` flag is also included if supported by the operating system. On POSIX, this is an alias for `createFileLink` and is therefore atomic.

Windows-specific errors: This operation may fail with `permissionErrorType` if the user lacks the privileges to create symbolic links. It may also fail with `illegalOperationErrorType` if the file system does not support symbolic links.

Since: directory-1.3.1.0

removeDirectoryLink :: FilePath -> IO () Source #

Remove an existing directory symbolic link.

On Windows, this is an alias for `removeDirectory`. On POSIX systems, this is an alias for `removeFile`.

See also: `removeFile`, which can remove an existing file symbolic link.

Since: directory-1.3.1.0

pathIsSymbolicLink :: FilePath -> IO Bool Source #

Check whether an existing `path` is a symbolic link. If `path` is a regular file or directory, `False` is returned. If `path` does not exist or is otherwise inaccessible, an exception is thrown (see below).

On Windows, this checks for `FILE_ATTRIBUTE_REPARSE_POINT`. In addition to symbolic links, the function also returns true on junction points. On POSIX systems, this checks for `S_IFLNK`.

The operation may fail with:

- `isDoesNotExistError` if the symbolic link does not exist; or
- `isPermissionError` if the user is not permitted to read the symbolic link.

Since: directory-1.3.0.0

getSymbolicLinkTarget :: FilePath -> IO FilePath Source #

Retrieve the target path of either a file or directory symbolic link. The returned path may not be absolute, may not exist, and may not even be a valid path.

On Windows systems, this calls `DeviceIoControl` with `FSCTL_GET_REPARSE_POINT`. In addition to symbolic links, the function also works on junction points. On POSIX systems, this calls `readlink`.

Windows-specific errors: This operation may fail with `illegalOperationErrorType` if the file system does not support symbolic links.

Since: directory-1.3.1.0

# Permissions

directory offers a limited (and quirky) interface for reading and setting file and directory permissions; see `getPermissions` and `setPermissions` for a discussion of their limitations. Because permissions are very difficult to implement portably across different platforms, users who wish to do more sophisticated things with permissions are advised to use other, platform-specific libraries instead. For example, if you are only interested in permissions on POSIX-like platforms, unix offers much more flexibility.

The `Permissions` type is used to record whether certain operations are permissible on a file/directory. `getPermissions` and `setPermissions` get and set these permissions, respectively. Permissions apply both to files and directories. For directories, the executable field will be `False`, and for files the searchable field will be `False`. Note that directories may be searchable without being readable, if permission has been given to use them as part of a path, but not to examine the directory contents.

Note that to change some, but not all permissions, a construct on the following lines must be used.

     makeReadable f = do
        p <- getPermissions f
        setPermissions f (p {readable = True})

data Permissions Source #

#### Instances

Instances details

Read Permissions Source # |
Instance details Defined in System.Directory.Internal.Common Methods readsPrec :: Int -> ReadS Permissions # readList :: ReadS [Permissions] # readPrec :: ReadPrec Permissions # readListPrec :: ReadPrec [Permissions] #
Show Permissions Source # |
Instance details Defined in System.Directory.Internal.Common Methods showsPrec :: Int -> Permissions -> ShowS # show :: Permissions -> String # showList :: [Permissions] -> ShowS #
Eq Permissions Source # |
Instance details Defined in System.Directory.Internal.Common Methods (==) :: Permissions -> Permissions -> Bool # (/=) :: Permissions -> Permissions -> Bool #
Ord Permissions Source # |
Instance details Defined in System.Directory.Internal.Common Methods compare :: Permissions -> Permissions -> Ordering # (<) :: Permissions -> Permissions -> Bool # (<=) :: Permissions -> Permissions -> Bool # (>) :: Permissions -> Permissions -> Bool # (>=) :: Permissions -> Permissions -> Bool # max :: Permissions -> Permissions -> Permissions # min :: Permissions -> Permissions -> Permissions #

emptyPermissions :: Permissions Source #

readable :: Permissions -> Bool Source #

writable :: Permissions -> Bool Source #

executable :: Permissions -> Bool Source #

searchable :: Permissions -> Bool Source #

setOwnerReadable :: Bool -> Permissions -> Permissions Source #

setOwnerWritable :: Bool -> Permissions -> Permissions Source #

setOwnerExecutable :: Bool -> Permissions -> Permissions Source #

setOwnerSearchable :: Bool -> Permissions -> Permissions Source #

getPermissions :: FilePath -> IO Permissions Source #

Get the permissions of a file or directory.

On Windows, the `writable` permission corresponds to the "read-only" attribute. The `executable` permission is set if the file extension is of an executable file type. The `readable` permission is always set.

On POSIX systems, this returns the result of `access`.

The operation may fail with:

- `isPermissionError` if the user is not permitted to access the permissions, or
- `isDoesNotExistError` if the file or directory does not exist.

setPermissions :: FilePath -> Permissions -> IO () Source #

Set the permissions of a file or directory.

On Windows, this is only capable of changing the `writable` permission, which corresponds to the "read-only" attribute. Changing the other permissions has no effect.

On POSIX systems, this sets the owner permissions.

The operation may fail with:

- `isPermissionError` if the user is not permitted to set the permissions, or
- `isDoesNotExistError` if the file or directory does not exist.

copyPermissions :: FilePath -> FilePath -> IO () Source #

Copy the permissions of one file to another. This reproduces the permissions more accurately than using `getPermissions` followed by `setPermissions`.

On Windows, this copies only the read-only attribute.

On POSIX systems, this is equivalent to `stat` followed by `chmod`.

# Timestamps

getAccessTime :: FilePath -> IO UTCTime Source #

Obtain the time at which the file or directory was last accessed.

The operation may fail with:

- `isPermissionError` if the user is not permitted to read the access time; or
- `isDoesNotExistError` if the file or directory does not exist.

Caveat for POSIX systems: This function returns a timestamp with sub-second resolution only if this package is compiled against `unix-2.6.0.0` or later and the underlying filesystem supports them.

Since: directory-1.2.3.0

getModificationTime :: FilePath -> IO UTCTime Source #

Obtain the time at which the file or directory was last modified.

The operation may fail with:

- `isPermissionError` if the user is not permitted to read the modification time; or
- `isDoesNotExistError` if the file or directory does not exist.

Caveat for POSIX systems: This function returns a timestamp with sub-second resolution only if this package is compiled against `unix-2.6.0.0` or later and the underlying filesystem supports them.

setAccessTime :: FilePath -> UTCTime -> IO () Source #

Change the time at which the file or directory was last accessed.

The operation may fail with:

- `isPermissionError` if the user is not permitted to alter the access time; or
- `isDoesNotExistError` if the file or directory does not exist.

Some caveats for POSIX systems:

- Not all systems support `utimensat`, in which case the function can only emulate the behavior by reading the modification time and then setting both the access and modification times together. On systems where `utimensat` is supported, the access time is set atomically with nanosecond precision.
- If compiled against a version of `unix` prior to `2.7.0.0`, the function would not be able to set timestamps with sub-second resolution. In this case, there would also be loss of precision in the modification time.

Since: directory-1.2.3.0

setModificationTime :: FilePath -> UTCTime -> IO () Source #

Change the time at which the file or directory was last modified.

The operation may fail with:

- `isPermissionError` if the user is not permitted to alter the modification time; or
- `isDoesNotExistError` if the file or directory does not exist.
- `InvalidArgument` on FAT32 file system if the time is before DOS Epoch (1 January 1980).

Some caveats for POSIX systems:

- Not all systems support `utimensat`, in which case the function can only emulate the behavior by reading the access time and then setting both the access and modification times together. On systems where `utimensat` is supported, the modification time is set atomically with nanosecond precision.
- If compiled against a version of `unix` prior to `2.7.0.0`, the function would not be able to set timestamps with sub-second resolution. In this case, there would also be loss of precision in the access time.

Since: directory-1.2.3.0

# Deprecated

isSymbolicLink :: FilePath -> IO Bool Source #

Deprecated: Use `pathIsSymbolicLink` instead