safecat  is  a  program  which  implements D. J. Bernstein's
maildir algorithm to copy stdin safely to a file in a speci-
fied directory. With safecat, the user is offered two assur-
ances. First, if safecat returns a successful  exit  status,
then  all  data is guaranteed to be saved in the destination
directory. Second, if  a  file  exists  in  the  destination
directory, placed there by safecat, then the file is guaran-
teed to be complete.

When saving data with safecat, the user specifies a destina-
tion  directory,  but  not  a  file  name.  The file name is
selected by safecat to ensure that  no  filename  collisions
occur,  even  if  many  safecat processes and other programs
implementing the maildir algorithm are writing to the direc-
tory  simultaneously.   If particular filenames are desired,
then the user should rename  the  file  after  safecat  com-
pletes.  In general, when spooling data with safecat, a sin-
gle, separate process should handle naming, collecting,  and
deleting  these  files.  Examples of such a process are dae-
mons, cron jobs, and mail readers.

WWW: ${HOMEPAGE}