LIO.TmpFile

This module creates new files and directories with unique names. Its functionality is similary to C's mkstemp() and mkdtemp() functions.

The high level interface

mkTmpFile

Arguments

:: IOMode

WriteMode, AppendMode, or ReadWriteMode (It is an error to use ReadMode.)

-> FilePath

Directory in which to create file

-> String

Suffix for new file name

-> IO (Handle, FilePath)

Returns open handle to new file, along with pathname of new file

Creates a new file with a unique name in a particular directory

mkTmpDir

Arguments

:: FilePath

Directory in which to create subdirectory

-> String

Suffix to append to new directory name

-> IO ((), FilePath)

Returns full path to new directory

Creates a new subdirectory with uniqe file name. Returns the pathname of the new directory as the second element of a pair, just for consistency with the interface to mkTmpFile. See mkTmpDir' if you don't want this behavior.

mkTmpDir'

Arguments

:: FilePath

Directory in which to create subdirectory

-> String

Suffix to append to new directory name

-> IO FilePath

Returns full path to new directory

Like mkTmpDir, but just returns the pathname of the new directory.

Some lower-level helper functions

mkTmp

Arguments

:: (FilePath -> IO a)

The function to execute (f)

-> FilePath

Directory to prepend to temp file names

-> String

Suffix for new file name

-> IO (a, FilePath)

The result of f and the FilePath on which it finally succeeded.

Executes a function on temporary file names until the function does not throw AlreadyExistsError. For example, mkTmpFile is defined as:

 mkTmpFile m d s = mkTmp (openFileExclusive m) d s

openFileExclusive :: IOMode -> FilePath -> IO Handle

Opens a file in exclusive mode, throwing AlreadyExistsError if the file name is already in use.

Functions for generating unique names

tmpName :: IO String

Return a temorary file name, based on the value of the current time of day clock.

nextTmpName :: String -> String

When the file name returned by tmpName already exists, nextTmpName modifies the file name to generate a new one.

serializele

Arguments

:: Int

Minimum number of bytes to return

-> Integer

The Integer to serialize

-> [Word8]

Serialize an Integer into an array of bytes, in little-endian order.

unserializele :: [Word8] -> Integer

Take an array of bytes containing an Integer serialized in little-endian order, and return the Integer.

For flushing temp files before rename

hSync :: Handle -> IO ()

Flushes a Handle to disk with fsync()