Copyright	(c) The University of Glasgow 2002
License	BSD-style (see the file libraries/base/LICENSE)
Maintainer	[email protected]
Stability	provisional
Portability	non-portable (requires POSIX)
Safe Haskell	Safe
Language	Haskell2010

File modes

unionFileModes :: FileMode -> FileMode -> FileMode Source

Combines the two file modes into one that contains modes that appear in either.

intersectFileModes :: FileMode -> FileMode -> FileMode Source

Combines two file modes into one that only contains modes that appear in both.

nullFileMode :: FileMode Source

No permissions.

ownerReadMode :: FileMode Source

Owner has read permission.

ownerWriteMode :: FileMode Source

Owner has write permission.

ownerExecuteMode :: FileMode Source

Owner has execute permission.

ownerModes :: FileMode Source

Owner has read, write and execute permission.

groupReadMode :: FileMode Source

Group has read permission.

groupWriteMode :: FileMode Source

Group has write permission.

groupExecuteMode :: FileMode Source

Group has execute permission.

groupModes :: FileMode Source

Group has read, write and execute permission.

otherReadMode :: FileMode Source

Others have read permission.

otherWriteMode :: FileMode Source

Others have write permission.

otherExecuteMode :: FileMode Source

Others have execute permission.

otherModes :: FileMode Source

Others have read, write and execute permission.

setUserIDMode :: FileMode Source

Set user ID on execution.

setGroupIDMode :: FileMode Source

Set group ID on execution.

stdFileMode :: FileMode Source

Owner, group and others have read and write permission.

accessModes :: FileMode Source

Owner, group and others have read, write and execute permission.

fileTypeModes :: FileMode Source

blockSpecialMode :: FileMode Source

characterSpecialMode :: FileMode Source

namedPipeMode :: FileMode Source

regularFileMode :: FileMode Source

directoryMode :: FileMode Source

symbolicLinkMode :: FileMode Source

socketMode :: FileMode Source

Setting file modes

setFileMode :: RawFilePath -> FileMode -> IO () Source

setFileMode path mode changes permission of the file given by path to mode. This operation may fail with throwErrnoPathIfMinus1_ if path doesn't exist or if the effective user ID of the current process is not that of the file's owner.

Note: calls chmod.

setFdMode :: Fd -> FileMode -> IO () Source

setFdMode fd mode acts like setFileMode but uses a file descriptor fd instead of a FilePath.

Note: calls fchmod.

setFileCreationMask :: FileMode -> IO FileMode Source

setFileCreationMask mode sets the file mode creation mask to mode. Modes set by this operation are subtracted from files and directories upon creation. The previous file creation mask is returned.

Note: calls umask.

Checking file existence and permissions

fileAccess :: RawFilePath -> Bool -> Bool -> Bool -> IO Bool Source

fileAccess name read write exec checks if the file (or other file system object) name can be accessed for reading, writing and/or executing. To check a permission set the corresponding argument to True.

Note: calls access.

fileExist :: RawFilePath -> IO Bool Source

Checks for the existence of the file.

Note: calls access.

File status

data FileStatus Source

POSIX defines operations to get information, such as owner, permissions, size and access times, about a file. This information is represented by the FileStatus type.

Note: see chmod.

Limitations: Support for high resolution timestamps is filesystem dependent:

• HFS+ volumes on OS X only support whole-second times.

Obtaining file status

getFileStatus :: RawFilePath -> IO FileStatus Source

getFileStatus path calls gets the FileStatus information (user ID, size, access times, etc.) for the file path.

Note: calls stat.

getFdStatus :: Fd -> IO FileStatus Source

getFdStatus fd acts as getFileStatus but uses a file descriptor fd.

Note: calls fstat.

getSymbolicLinkStatus :: RawFilePath -> IO FileStatus Source

Acts as getFileStatus except when the RawFilePath refers to a symbolic link. In that case the FileStatus information of the symbolic link itself is returned instead of that of the file it points to.

Note: calls lstat.

Querying file status

deviceID :: FileStatus -> DeviceID Source

ID of the device on which this file resides.

fileID :: FileStatus -> FileID Source

inode number

fileMode :: FileStatus -> FileMode Source

File mode (such as permissions).

linkCount :: FileStatus -> LinkCount Source

Number of hard links to this file.

fileOwner :: FileStatus -> UserID Source

ID of owner.

fileGroup :: FileStatus -> GroupID Source

ID of group.

specialDeviceID :: FileStatus -> DeviceID Source

Describes the device that this file represents.

fileSize :: FileStatus -> FileOffset Source

Size of the file in bytes. If this file is a symbolic link the size is the length of the pathname it contains.

accessTime :: FileStatus -> EpochTime Source

Time of last access.

modificationTime :: FileStatus -> EpochTime Source

Time of last modification.

statusChangeTime :: FileStatus -> EpochTime Source

Time of last status change (i.e. owner, group, link count, mode, etc.).

accessTimeHiRes :: FileStatus -> POSIXTime Source

Time of last access in sub-second resolution. Depends on the timestamp resolution of the underlying filesystem.

modificationTimeHiRes :: FileStatus -> POSIXTime Source

Time of last modification in sub-second resolution. Depends on the timestamp resolution of the underlying filesystem.

statusChangeTimeHiRes :: FileStatus -> POSIXTime Source

Time of last status change (i.e. owner, group, link count, mode, etc.) in sub-second resolution. Depends on the timestamp resolution of the underlying filesystem.

isBlockDevice :: FileStatus -> Bool Source

Checks if this file is a block device.

isCharacterDevice :: FileStatus -> Bool Source

Checks if this file is a character device.

isNamedPipe :: FileStatus -> Bool Source

Checks if this file is a named pipe device.

isRegularFile :: FileStatus -> Bool Source

Checks if this file is a regular file device.

isDirectory :: FileStatus -> Bool Source

Checks if this file is a directory device.

isSymbolicLink :: FileStatus -> Bool Source

Checks if this file is a symbolic link device.

isSocket :: FileStatus -> Bool Source

Checks if this file is a socket device.

fileBlockSize :: FileStatus -> Maybe CBlkSize Source

Gives the preferred block size for efficient filesystem I/O in bytes. Returns Nothing if st_blocksize is not supported on this platform.

fileBlocks :: FileStatus -> Maybe CBlkCnt Source

Number of blocks allocated for this file, in units of 512-bytes. Returns Nothing if st_blocks is not supported on this platform.

Extended file status

newtype ExtendedFileStatus Source

newtype CAttributes Source

haveStatx :: Bool Source

Whether statx is available on this platform and getExtendedFileStatus and related functions will work.

Obtaining extended file status

getExtendedFileStatus Source

Gets extended file status information.

The target file to open is identified in one of the following ways:

• If pathname begins with a slash, then it is an absolute pathname that identifies the target file. In this case, dirfd is ignored
• If pathname is a string that begins with a character other than a slash and dirfd is a file descriptor that refers to a directory, then pathname is a relative pathname that is interpreted relative to the directory referred to by dirfd. (See openat(2) for an explanation of why this is useful.)
• If pathname is an empty string and the EmptyPath flag is specified in flags (see below), then the target file is the one referred to by the file descriptor dirfd.

Note: calls statx.

Flags

newtype StatxFlags Source

Statx flags.

See the pattern synonyms for possible flags. These are combined via (<>). Flags can be tested via (.&.).

The following flags influence pathname-based lookup:

• EmptyPath
• NoAutoMount
• SymlinkNoFollow

The following flags can be used to control what sort of synchronization the kernel will do when querying a file on a remote filesystem:

• SyncAsStat
• ForceSync
• DontSync

defaultStatxFlags :: StatxFlags Source

pattern EmptyPath :: StatxFlags Source

If pathname to getExtendedFileStatus is an empty string, operate on the file referred to by the 'Maybe Fd' argument.

In this case, it can refer to any type of file, not just a directory.

pattern NoAutoMount :: StatxFlags Source

Don't automount the terminal ("basename") component of pathname if it is a directory that is an automount point. This allows the caller to gather attributes of an automount point (rather than the location it would mount). This flag can be used in tools that scan directories to prevent mass-automounting of a directory of automount points. This flag has no effect if the mount point has already been mounted over.

pattern SymlinkNoFollow :: StatxFlags Source

If pathname is a symbolic link, do not dereference it: instead return information about the link itself, like lstat(2).

pattern SyncAsStat :: StatxFlags Source

Do whatever stat(2) does. This is the default and is very much filesystem-specific.

pattern ForceSync :: StatxFlags Source

Force the attributes to be synchronized with the server. This may require that a network filesystem perform a data writeback to get the timestamps correct.

pattern DontSync :: StatxFlags Source

Don't synchronize anything, but rather just take whatever the system has cached if possible. This may mean that the information returned is approximate, but, on a network filesystem, it may not involve a round trip to the server - even if no lease is held.

Mask

newtype StatxMask Source

Mask argument to statx. It's used to tell the kernel which fields the caller is interested in.

See the pattern synonyms for possible masks. These are combined via (<>). Masks can be tested via (.&.).

defaultStatxMask :: StatxMask Source

pattern StatxType :: StatxMask Source

Want stx_mode & S_IFMT.

pattern StatxMode :: StatxMask Source

Want stx_mode & ~S_IFMT.

pattern StatxNlink :: StatxMask Source

Want stx_nlink.

pattern StatxUid :: StatxMask Source

Want stx_uid.

pattern StatxGid :: StatxMask Source

Want stx_gid.

pattern StatxAtime :: StatxMask Source

Want stx_atime.

pattern StatxMtime :: StatxMask Source

Want stx_mtime.

pattern StatxCtime :: StatxMask Source

Want stx_ctime.

pattern StatxIno :: StatxMask Source

Want stx_ino.

pattern StatxSize :: StatxMask Source

Want stx_size.

pattern StatxBlocks :: StatxMask Source

Want stx_blocks.

pattern StatxBasicStats :: StatxMask Source

Want all of the above.

pattern StatxBtime :: StatxMask Source

Want stx_btime.

pattern StatxMntId :: StatxMask Source

Want stx_mnt_id.

pattern StatxAll :: StatxMask Source

Want all currently available fields.

Querying extended file status

fileBlockSizeX :: ExtendedFileStatus -> CBlkSize Source

The "preferred" block size for efficient filesystem I/O. (Writing to a file in smaller chunks may cause an inefficient read-mod‐ify-rewrite.)

linkCountX :: ExtendedFileStatus -> CNlink Source

The number of hard links on a file.

fileOwnerX :: ExtendedFileStatus -> UserID Source

Te user ID of the owner of the file.

fileGroupX :: ExtendedFileStatus -> GroupID Source

The ID of the group owner of the file.

fileModeX :: ExtendedFileStatus -> FileMode Source

The file type and mode. See inode(7) for details.

fileIDX :: ExtendedFileStatus -> FileID Source

The inode number of the file.

fileSizeX :: ExtendedFileStatus -> Word64 Source

The size of the file (if it is a regular file or a symbolic link) in bytes. The size of a symbolic link is the length of the pathname it contains, without a terminating null byte.

fileBlocksX :: ExtendedFileStatus -> Word64 Source

The number of blocks allocated to the file on the medium, in 512-byte units. (This may be smaller than stx_size/512 when the file has holes.)

accessTimeHiResX :: ExtendedFileStatus -> POSIXTime Source

The file's last access timestamp.

creationTimeHiResX :: ExtendedFileStatus -> POSIXTime Source

The file's creation timestamp.

statusChangeTimeHiResX :: ExtendedFileStatus -> POSIXTime Source

The file's last status change timestamp.

modificationTimeHiResX :: ExtendedFileStatus -> POSIXTime Source

The file's last modification timestamp.

deviceIDX :: ExtendedFileStatus -> DeviceID Source

ID of the device on which this file resides.

specialDeviceIDX :: ExtendedFileStatus -> DeviceID Source

Describes the device that this file represents.

mountIDX :: ExtendedFileStatus -> Word64 Source

The mount ID of the mount containing the file. This is the same number reported by name_to_handle_at(2) and corresponds to the number in the first field in one of the records in procself/mountinfo.

fileCompressedX :: ExtendedFileStatus -> Bool Source

The file is compressed by the filesystem and may take extra resources to access. This is an extended attribute.

fileImmutableX :: ExtendedFileStatus -> Bool Source

The file cannot be modified: it cannot be deleted or renamed, no hard links can be created to this file and no data can be written to it. See chattr(1). This is an extended attribute.

fileAppendX :: ExtendedFileStatus -> Bool Source

The file can only be opened in append mode for writing. Random access writing is not permitted. See chattr(1). This is an extended attribute.

fileNoDumpX :: ExtendedFileStatus -> Bool Source

File is not a candidate for backup when a backup program such as dump(8) is run. See chattr(1). This is an extended attribute.

fileEncryptedX :: ExtendedFileStatus -> Bool Source

A key is required for the file to be encrypted by the filesystem. This is an extended attribute.

fileVerityX :: ExtendedFileStatus -> Bool Source

The file has fs-verity enabled. It cannot be written to, and all reads from it will be verified against a cryptographic hash that covers the entire file (e.g., via a Merkle tree). This is an extended attribute. Since Linux 5.5.

fileDaxX :: ExtendedFileStatus -> Bool Source

The file is in the DAX (cpu direct access) state. This is an extended attribute. Since Linux 5.8.

isBlockDeviceX :: ExtendedFileStatus -> Bool Source

Checks if this file is a block device.

isCharacterDeviceX :: ExtendedFileStatus -> Bool Source

Checks if this file is a character device.

isNamedPipeX :: ExtendedFileStatus -> Bool Source

Checks if this file is a named pipe device.

isRegularFileX :: ExtendedFileStatus -> Bool Source

Checks if this file is a regular file device.

isDirectoryX :: ExtendedFileStatus -> Bool Source

Checks if this file is a directory device.

isSymbolicLinkX :: ExtendedFileStatus -> Bool Source

Checks if this file is a symbolic link device.

isSocketX :: ExtendedFileStatus -> Bool Source

Checks if this file is a socket device.

Creation

createNamedPipe :: RawFilePath -> FileMode -> IO () Source

createNamedPipe fifo mode creates a new named pipe, fifo, with permissions based on mode. May fail with throwErrnoPathIfMinus1_ if a file named name already exists or if the effective user ID of the current process doesn't have permission to create the pipe.

Note: calls mkfifo.

createDevice :: RawFilePath -> FileMode -> DeviceID -> IO () Source

createDevice path mode dev creates either a regular or a special file depending on the value of mode (and dev). mode will normally be either blockSpecialMode or characterSpecialMode. May fail with throwErrnoPathIfMinus1_ if a file named name already exists or if the effective user ID of the current process doesn't have permission to create the file.

Note: calls mknod.

Hard links

createLink :: RawFilePath -> RawFilePath -> IO () Source

createLink old new creates a new path, new, linked to an existing file, old.

Note: calls link.

removeLink :: RawFilePath -> IO () Source

removeLink path removes the link named path.

Note: calls unlink.

Symbolic links

createSymbolicLink :: RawFilePath -> RawFilePath -> IO () Source

createSymbolicLink file1 file2 creates a symbolic link named file2 which points to the file file1.

Symbolic links are interpreted at run-time as if the contents of the link had been substituted into the path being followed to find a file or directory.

Note: calls symlink.

readSymbolicLink :: RawFilePath -> IO RawFilePath Source

Reads the RawFilePath pointed to by the symbolic link and returns it.

Note: calls readlink.

Renaming files

rename :: RawFilePath -> RawFilePath -> IO () Source

rename old new renames a file or directory from old to new.

Note: calls rename.

Changing file ownership

setOwnerAndGroup :: RawFilePath -> UserID -> GroupID -> IO () Source

setOwnerAndGroup path uid gid changes the owner and group of path to uid and gid, respectively.

If uid or gid is specified as -1, then that ID is not changed.

Note: calls chown.

setFdOwnerAndGroup :: Fd -> UserID -> GroupID -> IO () Source

Acts as setOwnerAndGroup but uses a file descriptor instead of a FilePath.

Note: calls fchown.

setSymbolicLinkOwnerAndGroup :: RawFilePath -> UserID -> GroupID -> IO () Source

Acts as setOwnerAndGroup but does not follow symlinks (and thus changes permissions on the link itself).

Note: calls lchown.

Changing file timestamps

setFileTimes :: RawFilePath -> EpochTime -> EpochTime -> IO () Source

setFileTimes path atime mtime sets the access and modification times associated with file path to atime and mtime, respectively.

Note: calls utime.

setFileTimesHiRes :: RawFilePath -> POSIXTime -> POSIXTime -> IO () Source

Like setFileTimes but timestamps can have sub-second resolution.

Note: calls utimensat or utimes. Support for high resolution timestamps is filesystem dependent with the following limitations:

• HFS+ volumes on OS X truncate the sub-second part of the timestamp.

setFdTimesHiRes :: Fd -> POSIXTime -> POSIXTime -> IO () Source

Like setFileTimesHiRes but uses a file descriptor instead of a path. This operation is not supported on all platforms. On these platforms, this function will raise an exception.

Note: calls futimens or futimes. Support for high resolution timestamps is filesystem dependent with the following limitations:

• HFS+ volumes on OS X truncate the sub-second part of the timestamp.

Since: unix-2.7.0.0

setSymbolicLinkTimesHiRes :: RawFilePath -> POSIXTime -> POSIXTime -> IO () Source

Like setFileTimesHiRes but does not follow symbolic links. This operation is not supported on all platforms. On these platforms, this function will raise an exception.

Note: calls utimensat or lutimes. Support for high resolution timestamps is filesystem dependent with the following limitations:

• HFS+ volumes on OS X truncate the sub-second part of the timestamp.

touchFile :: RawFilePath -> IO () Source

touchFile path sets the access and modification times associated with file path to the current time.

Note: calls utime.

touchFd :: Fd -> IO () Source

Like touchFile but uses a file descriptor instead of a path. This operation is not supported on all platforms. On these platforms, this function will raise an exception.

Note: calls futimes.

Since: unix-2.7.0.0

touchSymbolicLink :: RawFilePath -> IO () Source

Like touchFile but does not follow symbolic links. This operation is not supported on all platforms. On these platforms, this function will raise an exception.

Note: calls lutimes.

Setting file sizes

setFileSize :: RawFilePath -> FileOffset -> IO () Source

Truncates the file down to the specified length. If the file was larger than the given length before this operation was performed the extra is lost.

Note: calls truncate.

setFdSize :: Fd -> FileOffset -> IO () Source

Acts as setFileSize but uses a file descriptor instead of a FilePath.

Note: calls ftruncate.

Find system-specific limits for a file

data PathVar Source

getPathVar :: RawFilePath -> PathVar -> IO Limit Source

getPathVar var path obtains the dynamic value of the requested configurable file limit or option associated with file or directory path. For defined file limits, getPathVar returns the associated value. For defined file options, the result of getPathVar is undefined, but not failure.

Note: calls pathconf.

getFdPathVar :: Fd -> PathVar -> IO Limit Source

getFdPathVar var fd obtains the dynamic value of the requested configurable file limit or option associated with the file or directory attached to the open channel fd. For defined file limits, getFdPathVar returns the associated value. For defined file options, the result of getFdPathVar is undefined, but not failure.

Note: calls fpathconf.