Ubuntu Manpage: incrond - inotify cron (incron) daemon

Provided by: incron_0.5.12-2build1_amd64

NAME

       incrond - inotify cron (incron) daemon

SYNOPSIS

       incrond [ -f file ] [ -n | -k ]

DESCRIPTION

The inotify cron daemon (incrond) is a daemon which monitors filesystem events and executes commands
defined in system and user tables. It's use is generally similar to cron(8).

incrond can be started from /etc/rc, /etc/rc.local and so on. It daemonizes itself (returns immediately)
and doesn't need to be started with & and through nohup(1). It can be run on foreground too.

incrond uses two categories of tables incrontab(5). System tables are usually located in /etc/incron.d
and are maintained outside of incron (e.g. by various applications). These tables work on root rights
level and thus any file may be watched and commands are executed with root privileges.

User tables are located in /var/spool/incron by default and have names based on user accounts. These
tables use users' access rights, thus only files which the user may access are watched. Commands are
executed with users' privileges.

If a table (incrontab) is changed incrond reacts immediately and reloads the table. Currently running
child processes (commands) are not affected.

There are two files determining whether an user is allowed to use incron. These files have very simple
syntax - one user name per line. If /etc/incron.allow exists the user must be noted there to be allowed
to use incron. Otherwise if /etc/incron.deny exists the user must not be noted there to use incron. If
none of these files exists there is no other restriction whether anybody may use incron. Location of
these files can be changed in the configuration.

The daemon itself is currently not protected against looping. If a command executed due to an event
causes the same event it leads to an infinite loop unless a flag mask containing loopable=true is
specified. Please beware of this and do not allow permission for use incron to unreliable users.

-n (or --foreground) option causes running on foreground. This is useful especially for testing,
debugging and optimization.

-k (or --kill) option terminates a running instance of incrond.

-f <FILE> (or --config=<FILE>) option specifies another location for the configuration file
(/etc/incron.conf is used by default).

Environment variables: For system tables, the default (the same as for incrond itself) environment
variable set is used. The same applies to root's table. For non-root user tables, the whole environment
is cleared and then only these variables are set: LOGNAME, USER, USERNAME, SHELL, HOME and PATH. The
variables (except PATH) take values from the user database (e.g. /etc/passwd). The PATH variable is set
to /usr/local/bin:/usr/bin:/bin:/usr/X11R6/bin.

BUGS

       incrond is currently not resistant against looping.

AUTHOR

       Andreas    Altair     Redmer     <altair.ibn.la.ahad.sy@gmail.com>     (please     report     bugs     to
       https://github.com/ar-/incron/issues ).  Lukas Jelinek <lukas@aiken.cz>.

COPYING