Atomically write to a file on POSIX-compliant systems while preserving
On most Unix systems,
mv is an atomic operation. This makes it simple to
write to a file atomically just by using the mv operation. However, this will
destroy the permissions on the original file. This library does the following
to preserve permissions while atomically writing to a file:
If an original file exists, take those permissions and apply them to the temp
mving the file into place.
If the original file does not exist, create a following with default
permissions (based on the currently-active umask).
This way, when the file is
mv'ed into place, the permissions will be the ones
held by the original file.
This library is based on similar implementations found in common libraries in
Ruby and Python:
Chef includes atomic update functionality>
atomic-write, import the module corresponding to the type you wish to
write atomically, e.g., to write a (strict) ByteString atomically:
> import System.AtomicWrite.Writer.ByteString
Then you can use the atomicWrite function that accepts a
FilePath and a
> atomicWrite myFilePath myByteString.