May 26, 2018
Safely write data to maildir directory
From the safecat README
safecat is an implementation of D. J. Bernstein’s maildir algorithm. It can be used to write mail messages to a qmail-style maildir, or to write data to a “spool” directory reliably. There are no lockfiles with safecat, and nothing is left to chance. If safecat returns a successful exit status, then you can be practically 100 sure your data is safely committed to disk. Further, if data is written to a directory using safecat or other implementations of the maildir algorithm, then every file in that directory is guaranteed to be complete. If safecat fails to write all of the data, there will be no file at all in the destination directory.
Of course, you know that such a thing cannot be between UNIX and the different hardware options available, a 100 guarantee is not possible. However, safecat takes every precaution possible in writing your data.