DOKK / manpages / debian 11 / bcron / bcron-update.8.en
bcron-update(8) System Manager's Manual bcron-update(8)

bcron-update - Update system crontabs.

bcron-update path [ path ... ]

bcron-update polls the named files or directories periodically to see if there are any new, changed, or removed files. When it detects changes, it mirrors those changes into the crontab spool directory. bcron-update runs as root in order to be able to read system files that would potentially be unreadable otherwise.

On Debian, if path is a directory, bcron-update skips files in this directory with names that do not solely consist of lower- and uppercase letters ('a'-'z', 'A'-'Z'), digits ('0'-'9'), underscores ('_'), and hyphens ('-').

To mirror modern vixie-cron's behavior, use:

bcron-update /etc/crontab /etc/cron.d

The spool directory for bcron. Defaults to /var/spool/cron.
After writing files and before moving them into their final location, bcron-update changes the ownership of the file to this user so that bcron-sched can read them.

bcron-sched(8)

bcron-update outputs three different kinds of messages about actions it is taking.

The named directory has been modified, and will be scanned to determine what files have been added or deleted.
-/etc/cron.d/oldfile
The named file no longer exists and will be removed from the spool.
+/etc/cron.d/newfile
The named file was either created or modified since the last scan, and will be copied into the spool.

Bruce Guenter <bruce@untroubled.org>