| 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 | Safe-Inferred |
| Language | Haskell2010 |
System.Directory
Description
System-independent interface to directory manipulation.
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
- getXdgDirectory :: XdgDirectory -> FilePath -> IO FilePath
- data XdgDirectoryList
- 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:
IOoperations in this package may throw anyIOError. No other types of exceptions shall be thrown.- The list of possible
IOErrorTypes 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 dirdir which is
initially empty, or as near to empty as the operating system
allows.
The operation may fail with:
isPermissionErrorThe process has insufficient privileges to perform the operation.[EROFS, EACCES]isAlreadyExistsErrorThe operand refers to a directory that already exists.[EEXIST]HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentThe operand is not a valid directory name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThere is no path to the directory.[ENOENT, ENOTDIR]isFullErrorInsufficient resources (virtual memory, process file descriptors, physical disk space, etc.) are available to perform the operation.[EDQUOT, ENOSPC, ENOMEM, EMLINK]InappropriateTypeThe 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 dirdir 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
The operation may fail with:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentThe operand is not a valid directory name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe directory does not exist.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EROFS, EACCES, EPERM]UnsatisfiedConstraintsImplementation-dependent constraints are not satisfied.[EBUSY, ENOTEMPTY, EEXIST]UnsupportedOperationThe implementation does not support removal in this situation.[EINVAL]InappropriateTypeThe operand refers to an existing non-directory object.[ENOTDIR]
removeDirectoryRecursive :: FilePath -> IO () Source #
removeDirectoryRecursive dir
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: 1.2.7.0
renameDirectory :: FilePath -> FilePath -> IO () Source #
renameDirectory old newremoveDirectory. 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:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentEither operand is not a valid directory name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe original directory does not exist, or there is no path to the target.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EROFS, EACCES, EPERM]isFullErrorInsufficient resources are available to perform the operation.[EDQUOT, ENOSPC, ENOMEM, EMLINK]UnsatisfiedConstraintsImplementation-dependent constraints are not satisfied.[EBUSY, ENOTEMPTY, EEXIST]UnsupportedOperationThe implementation does not support renaming in this situation.[EINVAL, EXDEV]InappropriateTypeEither path refers to an existing non-directory object.[ENOTDIR, EISDIR]
listDirectory :: FilePath -> IO [FilePath] Source #
listDirectory dir. and ..).
The operation may fail with:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentThe operand is not a valid directory name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe directory does not exist.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EACCES]isFullErrorInsufficient resources are available to perform the operation.[EMFILE, ENFILE]InappropriateTypeThe path refers to an existing non-directory object.[ENOTDIR]
Since: 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:
HardwareFaultA physical I/O error has occurred.[EIO]isDoesNotExistErrorThere is no path referring to the working directory.[EPERM, ENOENT, ESTALE...]isPermissionErrorThe process has insufficient privileges to perform the operation.[EACCES]isFullErrorInsufficient resources are available to perform the operation.UnsupportedOperationThe 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:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentThe operand is not a valid directory name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe directory does not exist.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EACCES]UnsupportedOperationThe operating system has no notion of current working directory, or the working directory cannot be dynamically changed.InappropriateTypeThe 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 getCurrentDirectory
and setCurrentDirectory.
Since: 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_rusing 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:
UnsupportedOperationThe operating system has no notion of home directory.isDoesNotExistErrorThe 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: 1.2.3.0
Constructors
| XdgData | For data files (e.g. images).
It uses the |
| XdgConfig | For configuration files.
It uses the |
| XdgCache | For non-essential files (e.g. cache).
It uses the |
| 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 Since: 1.3.7.0 |
Instances
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: 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: 1.3.2.0
Constructors
| XdgDataDirs | For data files (e.g. images).
It uses the |
| XdgConfigDirs | For configuration files.
It uses the |
Instances
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 #
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:
UnsupportedOperationThe operating system has no notion of application-specific data directory.isDoesNotExistErrorThe 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:
UnsupportedOperationThe operating system has no notion of document directory.isDoesNotExistErrorThe 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:
UnsupportedOperationThe 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:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentThe operand is not a valid file name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe file does not exist.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EROFS, EACCES, EPERM]UnsatisfiedConstraintsImplementation-dependent constraints are not satisfied.[EBUSY]InappropriateTypeThe operand refers to an existing directory.[EPERM, EINVAL]
renameFile :: FilePath -> FilePath -> IO () Source #
renameFile old new
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:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentEither operand is not a valid file name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe original file does not exist, or there is no path to the target.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EROFS, EACCES, EPERM]isFullErrorInsufficient resources are available to perform the operation.[EDQUOT, ENOSPC, ENOMEM, EMLINK]UnsatisfiedConstraintsImplementation-dependent constraints are not satisfied.[EBUSY]UnsupportedOperationThe implementation does not support renaming in this situation.[EXDEV]InappropriateTypeEither path refers to an existing directory.[ENOTDIR, EISDIR, EINVAL, EEXIST, ENOTEMPTY]
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:
HardwareFaultA physical I/O error has occurred.[EIO]InvalidArgumentEither operand is not a valid file name.[ENAMETOOLONG, ELOOP]isDoesNotExistErrorThe original file does not exist, or there is no path to the target.[ENOENT, ENOTDIR]isPermissionErrorThe process has insufficient privileges to perform the operation.[EROFS, EACCES, EPERM]isFullErrorInsufficient resources are available to perform the operation.[EDQUOT, ENOSPC, ENOMEM, EMLINK]UnsatisfiedConstraintsImplementation-dependent constraints are not satisfied.[EBUSY]UnsupportedOperationThe implementation does not support renaming in this situation.[EXDEV]InappropriateTypeEither 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: 1.2.7.0
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.
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: 1.2.6.0
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: 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: 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 namecreateProcess
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: 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: 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: 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: 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 exists and satisfies the
predicate. If so, </> namedir 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.</> name
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: 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: 1.2.4.0
Symbolic links
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: 1.3.1.0
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: 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: 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:
isDoesNotExistErrorif the symbolic link does not exist; orisPermissionErrorif the user is not permitted to read the symbolic link.
Since: 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: 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
| Eq Permissions Source # | |
Defined in System.Directory.Internal.Common | |
| Ord Permissions Source # | |
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 # | |
| Read Permissions Source # | |
Defined in System.Directory.Internal.Common Methods readsPrec :: Int -> ReadS Permissions # readList :: ReadS [Permissions] # readPrec :: ReadPrec Permissions # readListPrec :: ReadPrec [Permissions] # | |
| Show Permissions Source # | |
Defined in System.Directory.Internal.Common Methods showsPrec :: Int -> Permissions -> ShowS # show :: Permissions -> String # showList :: [Permissions] -> ShowS # | |
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:
isPermissionErrorif the user is not permitted to access the permissions, orisDoesNotExistErrorif 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:
isPermissionErrorif the user is not permitted to set the permissions, orisDoesNotExistErrorif 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:
isPermissionErrorif the user is not permitted to read the access time; orisDoesNotExistErrorif 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: 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:
isPermissionErrorif the user is not permitted to read the modification time; orisDoesNotExistErrorif 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:
isPermissionErrorif the user is not permitted to alter the access time; orisDoesNotExistErrorif 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 whereutimensatis supported, the access time is set atomically with nanosecond precision. - If compiled against a version of
unixprior to2.7.0.0, 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: 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:
isPermissionErrorif the user is not permitted to alter the modification time; orisDoesNotExistErrorif 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 access time and then setting both the access and modification times together. On systems whereutimensatis supported, the modification time is set atomically with nanosecond precision. - If compiled against a version of
unixprior to2.7.0.0, 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: 1.2.3.0
Deprecated
isSymbolicLink :: FilePath -> IO Bool Source #
Deprecated: Use pathIsSymbolicLink instead