Atomically write to a file; profiling libraries

 Atomically write to a file on POSIX-compliant systems while preserving
 permissions.
 .
 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 file before `mv`ing 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.
 .
 This package provides a library for the Haskell programming language, compiled
 for profiling. See http://www.haskell.org/ for more information on Haskell.