haskell98-2.0.0.3: Compatibility with Haskell 98

Safe Haskell | Trustworthy
Language | Haskell98

Directory

Synopsis

- data Permissions = Permissions {
  - readable :: Bool
  - writable :: Bool
  - executable :: Bool
  - searchable :: Bool
  }
- createDirectory :: FilePath -> IO ()
- removeDirectory :: FilePath -> IO ()
- removeFile :: FilePath -> IO ()
- renameDirectory :: FilePath -> FilePath -> IO ()
- renameFile :: FilePath -> FilePath -> IO ()
- getDirectoryContents :: FilePath -> IO [FilePath]
- getCurrentDirectory :: IO FilePath
- setCurrentDirectory :: FilePath -> IO ()
- doesFileExist :: FilePath -> IO Bool
- doesDirectoryExist :: FilePath -> IO Bool
- getPermissions :: FilePath -> IO Permissions
- setPermissions :: FilePath -> Permissions -> IO ()
- getModificationTime :: FilePath -> IO UTCTime

# Documentation

data Permissions

Constructors

Permissions |

Fields

readable :: Bool
writable :: Bool
executable :: Bool
searchable :: Bool

Instances

Eq Permissions |
Ord Permissions |
Read Permissions |
Show Permissions |

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` / `PermissionDenied` The process has insufficient privileges to perform the operation. `[EROFS, EACCES]`
- `isAlreadyExistsError` / `AlreadyExists` 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]`
- `NoSuchThing` There is no path to the directory. `[ENOENT, ENOTDIR]`
- `ResourceExhausted` 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]`

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` / `NoSuchThing` The directory does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` / `PermissionDenied` 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]`

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` / `NoSuchThing` The file does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` / `PermissionDenied` 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]`

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` / `NoSuchThing` The original directory does not exist, or there is no path to the target. `[ENOENT, ENOTDIR]`
- `isPermissionError` / `PermissionDenied` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `ResourceExhausted` 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]`

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 atomically 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.

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` / `NoSuchThing` The original file does not exist, or there is no path to the target. `[ENOENT, ENOTDIR]`
- `isPermissionError` / `PermissionDenied` The process has insufficient privileges to perform the operation. `[EROFS, EACCES, EPERM]`
- `ResourceExhausted` 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]`

getDirectoryContents :: FilePath -> IO [FilePath] Source

``getDirectoryContents` dir` returns a list of all entries in dir.

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` / `NoSuchThing` The directory does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` / `PermissionDenied` The process has insufficient privileges to perform the operation. `[EACCES]`
- `ResourceExhausted` Insufficient resources are available to perform the operation. `[EMFILE, ENFILE]`
- `InappropriateType` The path refers to an existing non-directory object. `[ENOTDIR]`

getCurrentDirectory :: IO FilePath Source

If the operating system has a notion of current directories, `getCurrentDirectory` returns an absolute path to the current directory of the calling process.

The operation may fail with:

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

Note that in a concurrent program, the current directory is global state shared between all threads of the process. When using filesystem operations from multiple threads, it is therefore highly recommended to use absolute rather than relative `FilePath`s.

setCurrentDirectory :: FilePath -> IO () Source

If the operating system has a notion of current directories, ``setCurrentDirectory` dir` changes the current directory of the calling process to dir.

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` / `NoSuchThing` The directory does not exist. `[ENOENT, ENOTDIR]`
- `isPermissionError` / `PermissionDenied` The process has insufficient privileges to perform the operation. `[EACCES]`
- `UnsupportedOperation` The operating system has no notion of current directory, or the current directory cannot be dynamically changed.
- `InappropriateType` The path refers to an existing non-directory object. `[ENOTDIR]`

Note that in a concurrent program, the current directory is global state shared between all threads of the process. When using filesystem operations from multiple threads, it is therefore highly recommended to use absolute rather than relative `FilePath`s.

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.

getPermissions :: FilePath -> IO Permissions

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

getModificationTime :: FilePath -> IO UTCTime Source

The `getModificationTime` operation returns the clock time at which the file or directory was last modified.

The operation may fail with:

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

Note: When linked against `unix-2.6.0.0` or later the reported time supports sub-second precision if provided by the underlying system call.