|Linux version||Apple System Log|
system logging and kernel message trapping,
Use of internet and unix domain sockets enables local and remote logging.
If an error occurs during parsing of the config file the whole line is ignored.
Prefix the destination filename with
- to omit sync'ing the file after every write to it.(reduces I/O load).
Cause ALL messages using the
(debug is the lowest priority, so all higher levels match) to go into
/var/log/daemons and don't sync I/O system:
Direct debug messages from all sources
All messages of the facility mail except those with the priority
mail.*;mail.!=info /var/log/mailAll messages from news.info (including) to news.crit (excluding)
mail.none or mail.!* or mail.!debugto skip all messages with a mail facility.
-r; Default: ignore network.
Sending and receiving syslogd
/etc/services must contain
syslog 514/udp otherwise syslogd will die.
To forward messages to another host :
syslog.conf for destination.
For example, to forward ALL messages to a remote host
If the remote hostname cannot be resolved at startup, Syslogd will try to resolve the name ten times and then complain. and ????
syslog-loops (bad) : forwarding messages to a syslogd that forwards them back.
In a network provide a central log server to have all the logs kept on one machine.
If the network consists of different domains logging will include fully qualfied names.
-s stripdomain off several domains other than the one the server is located in and only log simple hostnames.
-l define single hosts as local machines.
The UDP socket used to forward messages to remote hosts or to receive messages from them is only opened when it is needed.
|to the name of the file. the fifo must be created with the mkfifo command before syslogd is started.
# Sample configuration to route kernel debugging # messages ONLY to /var/log/debug which is a named pipe. kern.=debug |/var/log/debug
klogdcan be run from
initor started as part of the
-n(don't switch to background.)
There is the potential for the syslogd daemon to be used as a conduit for a denial of service attack. A rogue program(mer) could flood the syslogd daemon with syslog messages resulting in the log files consuming all the remaining space on the filesystem. Activating logging over the inet domain sockets will expose a system to risks outside of programs or individuals on the local machine.
There are a number of methods of protecting a machine:
ext2filesystem which can be configured to limit a percentage of a filesystem to usage by root only, requiring syslogd to be run as a non-root process.
-dverbose display of activity is output to stdout.
When the configuration file is read a tabular report is output:
numbersequence number representing the position in the internal data structure.
facility(only the left most are used. )
actionwhen a message is received that matches the pattern.
argumentsadditional arguments to the actions
/dev/log, socket used by local syslog
/var/run/syslogd.pid, file containing the process id of syslogd.
syslog 514/udp syslog-conn 601/udp # Reliable Syslog Service syslog-conn 601/tcp # Reliable Syslog Service
If an error occurs in one line the whole rule is ignored. (Don't forget the
# to preceed comments (NOT ALL VERSIONS)
Syslogd doesn't change the permissions of logfiles.
created files are world readable.
savelog(8) to rotate logfiles.
It is a security hole if everybody is able to message from the
syslogBDS really Mac OSX ; darwin syslog-ngBalaBit Ltd version syslog.conf klogd(8), logger, syslog(2), syslog(3), services(5), savelog(8)
From smacker OS X 10.5.7 6/18/09
# Emergency (0) note counter-intuitive Emergency has a level less than Debug.
# Alert # Critical # Error # Warning # Notice # Info # Debug
# DONT Send messages to the serial port.
# authpriv log file should be restricted access
##see above *.err /var/log/03-err.log
##see above *.notice /var/log/05-notice.log
Collaborators: Syslogd is taken from BSD sources, Greg Wettstein (firstname.lastname@example.org) performed the port to Linux,