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SYSLOGD(8)                BSD System Manager's Manual               SYSLOGD(8)

     syslogd -- log systems messages

     syslogd [-46Acdknosuv] [-a allowed_peer] [-b bind_address]
             [-f config_file] [-l [mode:]path] [-m mark_interval]
             [-P pid_file] [-p log_socket]

     The syslogd utility reads and logs messages to the system console, log
     files, other machines and/or users as specified by its configuration

     The options are as follows:

     -4      Force syslogd to use IPv4 addresses only.

     -6      Force syslogd to use IPv6 addresses only.

     -A      Ordinarily, syslogd tries to send the message to only one address
             even if the host has more than one A or AAAA record.  If this
             option is specified, syslogd tries to send the message to all

     -a allowed_peer
             Allow allowed_peer to log to this syslogd using UDP datagrams.
             Multiple -a options may be specified.

             Allowed_peer can be any of the following:

             ipaddr/masklen[:service]    Accept datagrams from ipaddr (in the
                                         usual dotted quad notation) with
                                         masklen bits being taken into account
                                         when doing the address comparison.
                                         ipaddr can be also IPv6 address by
                                         enclosing the address with '[' and
                                         ']'.  If specified, service is the
                                         name or number of an UDP service (see
                                         services(5)) the source packet must
                                         belong to.  A service of '*' allows
                                         packets being sent from any UDP port.
                                         The default service is 'syslog'.  If
                                         ipaddr is IPv4 address, a missing
                                         masklen will be substituted by the
                                         historic class A or class B netmasks
                                         if ipaddr belongs into the address
                                         range of class A or B, respectively,
                                         or by 24 otherwise.  If ipaddr is
                                         IPv6 address, a missing masklen will
                                         be substituted by 128.

             domainname[:service]        Accept datagrams where the reverse
                                         address lookup yields domainname for
                                         the sender address.  The meaning of
                                         service is as explained above.

             *domainname[:service]       Same as before, except that any
                                         source host whose name ends in
                                         domainname will get permission.

             The -a options are ignored if the -s option is also specified.

     -b bind_address
             Specify one specific IP address or hostname to bind to.  If a
             hostname is specified, the IPv4 or IPv6 address which corresponds
             to it is used.

     -c      Disable the compression of repeated instances of the same line
             into a single line of the form ``last message repeated N times''
             when the output is a pipe to another program.  If specified
             twice, disable this compression in all cases.

     -d      Put syslogd into debugging mode.  This is probably only of use to
             developers working on syslogd.

     -f      Specify the pathname of an alternate configuration file; the
             default is /etc/syslog.conf.

     -k      Disable the translation of messages received with facility
             ``kern'' to facility ``user''.  Usually the ``kern'' facility is
             reserved for messages read directly from /dev/klog.

     -m      Select the number of minutes between ``mark'' messages; the
             default is 20 minutes.

     -n      Disable dns query for every request.

     -o      Prefix kernel messages with the full kernel boot file as deter-
             mined by getbootfile(3).  Without this, the kernel message prefix
             is always ``kernel:''.

     -p      Specify the pathname of an alternate log socket to be used
             instead; the default is /var/run/log.

     -P      Specify an alternative file in which to store the process ID.
             The default is /var/run/syslog.pid.

     -S      Specify the pathname of an alternate log socket for privileged
             applications to be used instead; the default is /var/run/logpriv.

     -l      Specify a location where syslogd should place an additional log
             socket.  The primary use for this is to place additional log
             sockets in /var/run/log of various chroot filespaces.  File per-
             missions for socket can be specified in octal representation
             before socket name, delimited with a colon.  Path to socket loca-
             tion must be absolute.

     -s      Operate in secure mode.  Do not log messages from remote
             machines.  If specified twice, no network socket will be opened
             at all, which also disables logging to remote machines.

     -u      Unique priority logging.  Only log messages at the specified pri-
             ority.  Without this option, messages at the stated priority or
             higher are logged.  This option changes the default comparison
             from ``=>'' to ``=''.

     -v      Verbose logging.  If specified once, the numeric facility and
             priority are logged with each locally-written message.  If speci-
             fied more than once, the names of the facility and priority are
             logged with each locally-written message.

     The syslogd utility reads its configuration file when it starts up and
     whenever it receives a hangup signal.  For information on the format of
     the configuration file, see syslog.conf(5).

     The syslogd utility reads messages from the UNIX domain sockets
     /var/run/log and /var/run/logpriv, from an Internet domain socket speci-
     fied in /etc/services, and from the special device /dev/klog (to read
     kernel messages).

     The syslogd utility creates its process ID file, by default
     /var/run/syslog.pid, and stores its process ID there.  This can be used
     to kill or reconfigure syslogd.

     The message sent to syslogd should consist of a single line.  The message
     can contain a priority code, which should be a preceding decimal number
     in angle braces, for example, '<5>'.  This priority code should map into
     the priorities defined in the include file <sys/syslog.h>.

     For security reasons, syslogd will not append to log files that do not
     exist; therefore, they must be created manually before running syslogd.

     /etc/syslog.conf     configuration file
     /var/run/syslog.pid  default process ID file
     /var/run/log         name of the UNIX domain datagram log socket
     /var/run/logpriv     UNIX socket for privileged applications
     /dev/klog            kernel log device

     logger(1), syslog(3), services(5), syslog.conf(5), newsyslog(8)

     The syslogd utility appeared in 4.3BSD.

     The -a, -s, -u, and -v options are FreeBSD 2.2 extensions.

     The ability to log messages received in UDP packets is equivalent to an
     unauthenticated remote disk-filling service, and should probably be dis-
     abled by default.  Some sort of inter-syslogd authentication mechanism
     ought to be worked out.  To prevent the worst abuse, use of the -a option
     is therefore highly recommended.

     The -a matching algorithm does not pretend to be very efficient; use of
     numeric IP addresses is faster than domain name comparison.  Since the
     allowed peer list is being walked linearly, peer groups where frequent
     messages are being anticipated from should be put early into the -a list.

     The log socket was moved from /dev to ease the use of a read-only root
     file system.  This may confuse some old binaries so that a symbolic link
     might be used for a transitional period.

BSD                               May 5, 2005                              BSD