Added section on exit status

git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup@421 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

branches/r0-12/rdiff-backup/rdiff-backup.1

@@ -885,6 +885,15 @@ option.
 The log file is not compressed and can become quite large if
 rdiff-backup is run with high verbosity.
 
+.SH EXIT STATUS
+
+If rdiff-backup finishes successfully, the exit status will be 0.  If
+there is an error, it will be non-zero (usually 1, but don't depend on
+this specific value).  When setting up rdiff-backup to run
+automatically (as from
+.BR cron (8)
+or similar) it is probably a good idea to check the exit code.
+
 .SH BUGS
 rdiff-backup uses the shell command
 .BR mknod (1)