syslogd(8) - NetBSD Manual Pages

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


NAME

     syslogd -- log systems messages


SYNOPSIS

     syslogd [-dnrSsTUv] [-b bind_address] [-f config_file] [-g group]
             [-m mark_interval] [-P file_list] [-p log_socket
             [-p log_socket2 ...]] [-t chroot_dir] [-u user]


DESCRIPTION

     syslogd reads and logs messages to the system console, log files, other
     machines and/or users as specified by its configuration file.  The
     options are as follows:

     -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.

     -d               Enable debugging to the standard output, and do not dis-
                      associate from the controlling terminal.

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

     -g group         Set GID to group after the sockets and log files have
                      been opened.

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

     -n               Do not perform hostname lookups; report only numeric
                      addresses.

     -P               Specify the pathname of a file containing a list of
                      sockets to be created.  The format of the file is simply
                      one socket per line.

     -p               Specify the pathname of a log socket.  Multiple -p
                      options create multiple log sockets.  If no -p arguments
                      are created, the default socket of /var/run/log is used.

     -r               Disable the compression of repeated instances of the
                      same line into a single line of the form ``last message
                      repeated N times''.

     -S               Sync kernel messages to disk immediately.

     -s               Select ``secure'' mode, in which syslogd does not listen
                      on a UDP socket but only communicates over a UNIX domain
                      socket.  This is valuable when the machine on which
                      syslogd runs is subject to attack over the network and
                      it is desired that the machine be protected from
                      attempts to remotely fill logs and similar attacks.

     -t chroot_dir    chroot(2) to chroot_dir after the sockets and log files
                      have been opened.

     -T               Always use the local time and date for messages received
                      from the network, instead of the timestamp field sup-
                      plied in the message by the remote host.  This is useful
                      if some of the originating hosts can't keep time prop-
                      erly or are unable to generate a correct timestamp.

     -u user          Set UID to user after the sockets and log files have
                      been opened.

     -U               Unique priority logging.  Only log messages at the pri-
                      ority specified by the selector in the configuration
                      file.  Without this option, messages at the specified
                      priority or higher are logged.  This option changes the
                      default priority comparison from `>=' to `='.

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

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

     syslogd reads messages from the UNIX domain socket /var/run/log, from an
     Internet domain socket specified in /etc/services, and from the special
     device /dev/klog (to read kernel messages).

     syslogd creates the file /var/run/syslogd.pid, and stores its process id
     there.  This can be used to kill or reconfigure syslogd.

     By using multiple -p options, one can set up many chroot environments by
     passing the pathname to the log socket (/var/run/log) in each chroot area
     to syslogd.  For example:
           syslogd -p /var/run/log -p /web/var/run/log -p /ftp/var/run/log

     Note: the normal log socket must now also be passed to syslogd.

     The logged message includes the date, time, and hostname (or pathname of
     the log socket).  Commonly, the program name and the process id is
     included.

     The date and time are taken from the received message.  If the format of
     the timestamp field is incorrect, time obtained from the local host is
     used instead.  This can be overridden by the -T flag.

     Accesses from UDP socket can be filtered by libwrap configuration files,
     like /etc/hosts.deny.  Specify ``syslogd'' in daemon_list portion of the
     configuration files.  Refer to hosts_access(5) for details.

   SYSLOG PROTOCOL NOTES
     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>.  See RFC 3164
     for detailed description of the message format.

     Messages from the local kernel that are not tagged with a priority code
     receive the default facility LOG_KERN and priority LOG_NOTICE.  All other
     untagged messages receive the default facility LOG_USER and priority
     LOG_NOTICE.


FILES

     /etc/syslog.conf      The configuration file.
     /var/run/syslogd.pid  The process id of current syslogd.
     /var/run/log          Name of the UNIX domain datagram log socket.
     /dev/klog             The kernel log device.


SEE ALSO

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

     The BSD syslog Protocol, RFC, 3164, August 2001.


HISTORY

     The syslogd command appeared in 4.3BSD.  Support for multiple log sockets
     appeared in NetBSD 1.4.  libwrap support appeared in NetBSD 1.6.

NetBSD 5.0                     February 1, 2008                     NetBSD 5.0