Advice parameter for fileAdvise operation.
For more details, see documentation of posix_fadvise(2).
Moduleunix-2.8.8.0Haskell2010
System.Posix.Fcntl
POSIX file control support
Contents
Synopsis
- data Advice
- value fileAdvise
- value fileAllocate
- value fileGetCaching
- value fileSetCaching
- Packageunix-2.8.8.0
- Exports5
- LanguageHaskell2010
- LicenceBSD-3-Clause
- SourceFcntl.hsc
File allocation
Performs posix_fadvise(2) operation on file-descriptor.
If platform does not provide posix_fadvise(2) fileAdvise
becomes a no-op.
(use #if HAVE_POSIX_FADVISE CPP guard to detect availability)
Performs posix_fallocate(2) operation on file-descriptor.
Throws IOError ("unsupported operation") if platform does not
provide posix_fallocate(2).
(use #if HAVE_POSIX_FALLOCATE CPP guard to detect availability).
File caching
Performs the fcntl(2) operation on a file-desciptor to get the cache mode.
If the cache mode is False, then cache effects for file system reads and writes are minimised or otherwise eliminated. If the cache mode is True, then cache effects occur like normal.
On Linux, FreeBSD, and NetBSD this checks whether the O_DIRECT file flag is
set.
Throws IOError ("unsupported operation") if platform does not support getting the cache mode.
Use #if HAVE_O_DIRECT CPP guard to detect availability. Use #include
"HsUnix.h" to bring HAVE_O_DIRECT into scope.
Performs the fcntl(2) operation on a file-desciptor to set the cache
mode.
If the cache mode is False, then cache effects for file system reads and writes are minimised or otherwise eliminated. If the cache mode is True, then cache effects occur like normal.
On Linux, FreeBSD, and NetBSD this sets the O_DIRECT file flag. On OSX,
this sets the F_NOCACHE fcntl flag.
Throws IOError ("unsupported operation") if platform does not support setting the cache mode.
Use #if HAVE_O_DIRECT || HAVE_F_NOCACHE CPP guard to detect availability.
Use #include "HsUnix.h" to bring HAVE_O_DIRECT and HAVE_F_NOCACHE into
scope.