Copyright | © 2016 Mark Karpov |
---|---|
License | BSD 3 clause |
Maintainer | Mark Karpov <markkarpov@openmailbox.org> |
Stability | experimental |
Portability | portable |
Safe Haskell | None |
Language | Haskell2010 |
This module provides interface to System.Directory for users of Path module. It also implements commonly used primitives like recursive scanning and copying of directories.
- createDir :: MonadIO m => Path b Dir -> m ()
- createDirIfMissing :: MonadIO m => Bool -> Path b Dir -> m ()
- ensureDir :: MonadIO m => Path b Dir -> m ()
- removeDir :: MonadIO m => Path b Dir -> m ()
- removeDirRecur :: MonadIO m => Path b Dir -> m ()
- renameDir :: MonadIO m => Path b0 Dir -> Path b1 Dir -> m ()
- listDir :: (MonadIO m, MonadThrow m) => Path b Dir -> m ([Path Abs Dir], [Path Abs File])
- listDirRecur :: (MonadIO m, MonadThrow m) => Path b Dir -> m ([Path Abs Dir], [Path Abs File])
- copyDirRecur :: (MonadIO m, MonadCatch m) => Path b0 Dir -> Path b1 Dir -> m ()
- getCurrentDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir)
- setCurrentDir :: MonadIO m => Path b Dir -> m ()
- withCurrentDir :: (MonadIO m, MonadMask m) => Path b Dir -> m a -> m a
- getHomeDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir)
- getAppUserDataDir :: (MonadIO m, MonadThrow m) => Path Rel Dir -> m (Path Abs Dir)
- getUserDocsDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir)
- getTempDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir)
- type family AbsPath path
- type family RelPath path
- class AnyPath path where
- canonicalizePath :: (MonadIO m, MonadThrow m) => path -> m (AbsPath path)
- makeAbsolute :: (MonadIO m, MonadThrow m) => path -> m (AbsPath path)
- makeRelative :: MonadThrow m => Path Abs Dir -> path -> m (RelPath path)
- makeRelativeToCurrentDir :: (MonadIO m, MonadThrow m) => path -> m (RelPath path)
- resolveFile :: (MonadIO m, MonadThrow m) => Path Abs Dir -> FilePath -> m (Path Abs File)
- resolveFile' :: (MonadIO m, MonadThrow m) => FilePath -> m (Path Abs File)
- resolveDir :: (MonadIO m, MonadThrow m) => Path Abs Dir -> FilePath -> m (Path Abs Dir)
- resolveDir' :: (MonadIO m, MonadThrow m) => FilePath -> m (Path Abs Dir)
- removeFile :: MonadIO m => Path b File -> m ()
- renameFile :: MonadIO m => Path b0 File -> Path b1 File -> m ()
- copyFile :: MonadIO m => Path b0 File -> Path b1 File -> m ()
- findExecutable :: MonadIO m => Path Rel File -> m (Maybe (Path Abs File))
- findFile :: (MonadIO m, MonadThrow m) => [Path b Dir] -> Path Rel File -> m (Maybe (Path Abs File))
- findFiles :: (MonadIO m, MonadThrow m) => [Path b Dir] -> Path Rel File -> m [Path Abs File]
- findFilesWith :: (MonadIO m, MonadThrow m) => (Path Abs File -> m Bool) -> [Path b Dir] -> Path Rel File -> m [Path Abs File]
- withTempFile :: (MonadIO m, MonadMask m) => Path b Dir -> String -> (Path Abs File -> Handle -> m a) -> m a
- withTempDir :: (MonadIO m, MonadMask m) => Path b Dir -> String -> (Path Abs Dir -> m a) -> m a
- withSystemTempFile :: (MonadIO m, MonadMask m) => String -> (Path Abs File -> Handle -> m a) -> m a
- withSystemTempDir :: (MonadIO m, MonadMask m) => String -> (Path Abs Dir -> m a) -> m a
- openTempFile :: (MonadIO m, MonadThrow m) => Path b Dir -> String -> m (Path Abs File, Handle)
- openBinaryTempFile :: (MonadIO m, MonadThrow m) => Path b Dir -> String -> m (Path Abs File, Handle)
- createTempDir :: (MonadIO m, MonadThrow m) => Path b Dir -> String -> m (Path Abs Dir)
- doesFileExist :: MonadIO m => Path b File -> m Bool
- doesDirExist :: MonadIO m => Path b Dir -> m Bool
- isLocationOccupied :: MonadIO m => Path b t -> m Bool
- forgivingAbsence :: (MonadIO m, MonadCatch m) => m a -> m (Maybe a)
- ignoringAbsence :: (MonadIO m, MonadCatch m) => m a -> m ()
- forgivingAbsence' :: (MonadIO m, MonadCatch m) => m a -> m ()
- 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 :: MonadIO m => Path b t -> m Permissions
- setPermissions :: MonadIO m => Path b t -> Permissions -> m ()
- copyPermissions :: MonadIO m => Path b0 t0 -> Path b1 t1 -> m ()
- getModificationTime :: MonadIO m => Path b t -> m UTCTime
Actions on directories
createDir :: MonadIO m => Path b Dir -> m () Source
creates a new directory createDir
dirdir
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]
:: MonadIO m | |
=> Bool | Create its parents too? |
-> Path b Dir | The path to the directory you want to make |
-> m () |
creates a new directory createDirIfMissing
parents dirdir
if it
doesn't exist. If the first argument is True
the function will also
create all parent directories if they are missing.
ensureDir :: MonadIO m => Path b Dir -> m () Source
Ensure that directory exists creating it and its parent directories if necessary. This is just a handy shortcut:
ensureDir = createDirIfMissing True
removeDir :: MonadIO m => Path b Dir -> m () Source
removes an existing directory removeDir
dirdir
. 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]
removeDirRecur :: MonadIO m => Path b Dir -> m () Source
removes an existing directory removeDirRecur
dirdir
together
with its contents and subdirectories. Within this directory, symbolic
links are removed without affecting their the targets.
changes the name of an existing directory from
renameDir
old newold
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 removeDir
. 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, renameDir
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]
:: (MonadIO m, MonadThrow m) | |
=> Path b Dir | Directory to list |
-> m ([Path Abs Dir], [Path Abs File]) | Sub-directories and files |
returns a list of all entries in listDir
dirdir
without the
special entries (.
and ..
). Entries are not sorted.
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]
Copy directory recursively. This is not smart about symbolic links, but tries to preserve permissions when possible. If destination directory already exists, new files and sub-directories will complement its structure, possibly overwriting old files if they happen to have the same name as the new ones.
Current working directory
getCurrentDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir) 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
).
The operation may fail with:
HardwareFault
A physical I/O error has occurred.[EIO]
isDoesNotExistError
orNoSuchThing
There is no path referring to the working directory.[EPERM, ENOENT, ESTALE...]
isPermissionError
orPermissionDenied
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 working directory.
setCurrentDir :: MonadIO m => Path b Dir -> m () 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
orNoSuchThing
The directory does not exist.[ENOENT, ENOTDIR]
isPermissionError
orPermissionDenied
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]
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 getCurrentDir
and
setCurrentDir
.
Pre-defined directories
getHomeDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir) 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 getAppUserDataDir
instead.
On Unix, getHomeDir
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>
.
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.
:: (MonadIO m, MonadThrow m) | |
=> Path Rel Dir | A relative path that is appended to the path |
-> m (Path Abs Dir) |
Obtain the path to a special directory for storing user-specific application data (traditional Unix location).
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.
getUserDocsDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir) 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 getAppUserDataDir
instead.
On Unix, getUserDocsDir
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.
getTempDir :: (MonadIO m, MonadThrow m) => m (Path Abs Dir) Source
Returns the current directory for temporary files.
On Unix, getTempDir
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.isDoesNotExistError
The temporary directory for the current user does not exist, or cannot be found.
Path transformation
type family AbsPath path Source
Closed type family describing how to get absolute version of given
Path
.
type family RelPath path Source
Closed type family describing how to get relative version of given
Path
.
class AnyPath path where Source
Class of things (Path
s) that can be canonicalized and made absolute.
canonicalizePath :: (MonadIO m, MonadThrow m) => path -> m (AbsPath path) Source
Make a path absolute and remove as many indirections from it as
possible. Indirections include the two special directories .
and
..
, as well as any symbolic links. The input path need not point to
an existing file or directory.
Note: if you require only an absolute path, use makeAbsolute
instead. Most programs need not care about whether a path contains
symbolic links.
Due to the fact that symbolic links and ..
are dependent on the state
of the existing filesystem, the function can only make a conservative,
best-effort attempt. Nevertheless, if the input path points to an
existing file or directory, then the output path shall also point to
the same file or directory.
Formally, symbolic links and ..
are removed from the longest prefix
of the path that still points to an existing file. The function is not
atomic, therefore concurrent changes in the filesystem may lead to
incorrect results.
(Despite the name, the function does not guarantee canonicity of the returned path due to the presence of hard links, mount points, etc.)
Similar to normalise
, an empty path is equivalent to the current
directory.
Known bug(s): on Windows, the function does not resolve symbolic links.
makeAbsolute :: (MonadIO m, MonadThrow m) => path -> m (AbsPath path) Source
Make a path absolute by prepending the current directory (if it isn't
already absolute) and applying normalise
to the result.
If the path is already absolute, the operation never fails. Otherwise,
the operation may fail with the same exceptions as
getCurrentDirectory
.
:: MonadThrow m | |
=> Path Abs Dir | Base directory |
-> path | Path that will be made relative to base directory |
-> m (RelPath path) |
Make a path relative to given directory.
makeRelativeToCurrentDir :: (MonadIO m, MonadThrow m) => path -> m (RelPath path) Source
Make a path relative to current working directory.
:: (MonadIO m, MonadThrow m) | |
=> Path Abs Dir | Base directory |
-> FilePath | Path to resolve |
-> m (Path Abs File) |
Append stringly-typed path to an absolute path and then canonicalize
it. This can throw the same exceptions as canonicalizePath
. In
particular, doesNotExistErrorType
is thrown if
resulting file does not exist and thus its path cannot be canonicalized.
The same as resolveFile
, but uses current working directory.
:: (MonadIO m, MonadThrow m) | |
=> Path Abs Dir | Base directory |
-> FilePath | Path to resolve |
-> m (Path Abs Dir) |
The same as resolveFile
, but for directories.
The same as resolveDir
, but uses current working directory.
Actions on files
removeFile :: MonadIO m => Path b File -> m () Source
removes the directory entry for an existing file
removeFile
filefile
, 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]
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.renameFile
old new
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]
copies the existing file from copyFile
old newold
to new
. If
the new
file already exists, it is atomically replaced by the old
file. Neither path may refer to an existing directory. The permissions of
old
are copied to new
, if possible.
:: MonadIO m | |
=> Path Rel File | Executable file name |
-> m (Maybe (Path Abs File)) | Path to found executable |
Given an executable file name, search for such file in the directories
listed in system PATH
. The returned value is the path to the found
executable or Nothing
if an executable with the given name was not
found. For example (findExecutable
"ghc") gives you the path to GHC.
The path returned by findExecutable
corresponds to the
program that would be executed by createProcess
when passed the same string (as a RawCommand, not a ShellCommand).
On Windows, findExecutable
calls the Win32 function SearchPath
, which
may search other places before checking the directories in PATH
. Where
it actually searches depends on registry settings, but notably includes
the directory containing the current executable. See
http://msdn.microsoft.com/en-us/library/aa365527.aspx for more details.
:: (MonadIO m, MonadThrow m) | |
=> [Path b Dir] | Set of directories to search in |
-> Path Rel File | Filename of interest |
-> m (Maybe (Path Abs File)) | Absolute path to file (if found) |
Search through the given set of directories for the given file.
:: (MonadIO m, MonadThrow m) | |
=> [Path b Dir] | Set of directories to search in |
-> Path Rel File | Filename of interest |
-> m [Path Abs File] | Absolute paths to all found files |
Search through the given set of directories for the given file and return a list of paths where the given file exists.
:: (MonadIO m, MonadThrow m) | |
=> (Path Abs File -> m Bool) | How to test the files |
-> [Path b Dir] | Set of directories to search in |
-> Path Rel File | Filename of interest |
-> m [Path Abs File] | Absolute paths to all found files |
Search through the given set of directories for the given file and with the given property (usually permissions) and return a list of paths where the given file exists and has the property.
Temporary files and directories
:: (MonadIO m, MonadMask m) | |
=> Path b Dir | Directory to create the file in |
-> String | File name template, see |
-> (Path Abs File -> Handle -> m a) | Callback that can use the file |
-> m a |
Use a temporary file that doesn't already exist.
Creates a new temporary file inside the given directory, making use of the template. The temporary file is deleted after use.
:: (MonadIO m, MonadMask m) | |
=> Path b Dir | Directory to create the file in |
-> String | Directory name template, see |
-> (Path Abs Dir -> m a) | Callback that can use the directory |
-> m a |
Create and use a temporary directory.
Creates a new temporary directory inside the given directory, making use of the template. The temporary directory is deleted after use.
:: (MonadIO m, MonadMask m) | |
=> String | File name template, see |
-> (Path Abs File -> Handle -> m a) | Callback that can use the file |
-> m a |
Create and use a temporary file in the system standard temporary directory.
Behaves exactly the same as withTempFile
, except that the parent
temporary directory will be that returned by getTempDir
.
:: (MonadIO m, MonadMask m) | |
=> String | Directory name template, see |
-> (Path Abs Dir -> m a) | Callback that can use the directory |
-> m a |
Create and use a temporary directory in the system standard temporary directory.
Behaves exactly the same as withTempDir
, except that the parent
temporary directory will be that returned by getTempDir
.
:: (MonadIO m, MonadThrow m) | |
=> Path b Dir | Directory to create file in |
-> String | File name template; if the template is "foo.ext" then the created
file will be |
-> m (Path Abs File, Handle) | Name of created file and its |
The function creates a temporary file in rw
mode. The created file
isn't deleted automatically, so you need to delete it manually.
The file is created with permissions such that only the current user can read/write it.
With some exceptions (see below), the file will be created securely in
the sense that an attacker should not be able to cause openTempFile to
overwrite another file on the filesystem using your credentials, by
putting symbolic links (on Unix) in the place where the temporary file is
to be created. On Unix the O_CREAT
and O_EXCL
flags are used to
prevent this attack, but note that O_EXCL
is sometimes not supported on
NFS filesystems, so if you rely on this behaviour it is best to use local
filesystems only.
:: (MonadIO m, MonadThrow m) | |
=> Path b Dir | Directory to create file in |
-> String | File name template, see |
-> m (Path Abs File, Handle) | Name of created file and its |
Like openTempFile
, but opens the file in binary mode. On Windows,
reading a file in text mode (which is the default) will translate CRLF
to LF
, and writing will translate LF
to CRLF
. This is usually what
you want with text files. With binary files this is undesirable; also, as
usual under Microsoft operating systems, text mode treats control-Z as
EOF. Binary mode turns off all special treatment of end-of-line and
end-of-file characters.
:: (MonadIO m, MonadThrow m) | |
=> Path b Dir | Directory to create file in |
-> String | Directory name template, see |
-> m (Path Abs Dir) | Name of created temporary directory |
Create temporary directory. The created directory isn't deleted automatically, so you need to delete it manually.
The directory is created with permissions such that only the current user can read/write it.
Existence tests
doesFileExist :: MonadIO m => Path b File -> m Bool Source
The operation doesFileExist
returns True
if the argument file
exists and is not a directory, and False
otherwise.
doesDirExist :: MonadIO m => Path b Dir -> m Bool Source
The operation doesDirExist
returns True
if the argument file exists
and is either a directory or a symbolic link to a directory, and False
otherwise.
isLocationOccupied :: MonadIO m => Path b t -> m Bool Source
Check if there is a file or directory on specified path.
forgivingAbsence :: (MonadIO m, MonadCatch m) => m a -> m (Maybe a) Source
If argument of the function throws a
doesNotExistErrorType
, Nothing
is returned (other
exceptions propagate). Otherwise the result is returned inside a Just
.
ignoringAbsence :: (MonadIO m, MonadCatch m) => m a -> m () Source
The same as forgivingAbsence
, but ignores result.
forgivingAbsence' :: (MonadIO m, MonadCatch m) => m a -> m () Source
Deprecated: Use ignoringAbsence
instead.
A synonym for ignoringAbsence
.
Permissions
data 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 :: MonadIO m => Path b t -> m Permissions Source
The getPermissions
operation returns the permissions for the file or
directory.
The operation may fail with:
isPermissionError
if the user is not permitted to access the permissions; orisDoesNotExistError
if the file or directory does not exist.
setPermissions :: MonadIO m => Path b t -> Permissions -> m () Source
The setPermissions
operation sets the permissions for the file or
directory.
The operation may fail with:
isPermissionError
if the user is not permitted to set the permissions; orisDoesNotExistError
if the file or directory does not exist.
Set permissions for the object found on second given path so they match permissions of the object on the first path.
Timestamps
getModificationTime :: MonadIO m => Path b t -> m 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; orisDoesNotExistError
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.