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syslog-ng(8)		  The syslog-ng OSE manual page 	    syslog-ng(8)

NAME
     syslog-ng - syslog-ng system logger application

SYNOPSIS
     syslog-ng [options]

DESCRIPTION
     This manual page is only an abstract.

     The syslog-ng OSE application is a flexible and highly scalable system log-
     ging  application.  Typically, syslog-ng OSE is used to manage log messages
     and implement centralized logging, where the aim is to collect the log mes-
     sages of several devices on a single, central log server. The different de-
     vices - called syslog-ng OSE clients - all run syslog-ng OSE,  and  collect
     the  log  messages from the various applications, files, and other sources.
     The clients send all important log messages to  the  remote  syslog-ng  OSE
     server, where the server sorts and stores them.

OPTIONS
     --caps
	 Run syslog-ng OSE process with the specified POSIX capability flags.

	    * If  the  --no-caps  option is not set, syslog-ng OSE has been com-
	      piled with the --enable-linux-caps compile option,  and  the  host
	      supports CAPSYSLOG, syslog-ng OSE uses the following capabilities:
	      "capnetbindservice,  capnetbroadcast, capnetraw, capdacreadsearch,
	      capdacoverride, capchown, capfowner=p capsyslog=ep"

	    * If the --no-caps option is not set, and the host does not  support
	      CAPSYSLOG, syslog-ng OSE uses the following capabilities: "capnet-
	      bindservice,  apnetbroadcast,  capnetraw, capdacreadsearch, capda-
	      coverride, capchown, capfowner=p capsys_admin=ep"

	    For example:

		       /Users/hofi/Develop/Balabit/syslog-ng/build/install/sbin/syslog-ng -Fv --caps cap_sys_admin,cap_chown,cap_dac_override,cap_net_bind_service,cap_fowner=pi

	    NOTE: The capabilities are not case sensitive, the following command
	    is also good:

		       /Users/hofi/Develop/Balabit/syslog-ng/build/install/sbin/syslog-ng -Fv --caps CAP_SYS_ADMIN,CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_NET_BIND_SERVICE,CAP_FOWNER=pi

	    For details on the capability flags, see the  following  man  pages:
	    cap_from_text(3) and capabilities(7)

     --cfgfile <file> or -f <file>
	 Use the specified configuration file.

     --chroot <dir> or -C <dir>
	 Change  root to the specified directory. The configuration file is read
     after chrooting so, the configuration file must be available within the ch-
     root. That way it is also possible to reload the syslog-ng  OSE  configura-
     tion after chrooting. However, note that the --user and --group options are
     resolved before chrooting.

     --check-startup
	 Available in syslog-ng OSE 4.5 and later versions.
	 This option can be used to perform a complete configuration initializa-
     tion  with  syslog-ng  OSE, then exit with the exit code indicating the re-
     sult. This option can also be used to check if the configuration is  seman-
     tically valid and that syslog-ng OSE can actually start. (The --syntax-only
     option catches only syntactical errors.)
	 Furthermore,  --check-startup can also be used in a Kubernetes environ-
     ment, to run it as a dedicated configuration check container.

     NOTE: This option is highly likely to fail if  another  syslog-ng	OSE  in-
     stance   is  running  in  the  background,  since	it  initializes  several
     processes, such as network listeners. In such a case, the	network  address
     would already be in use.

     --control <file> or -c <file>
	 Set  the  location  of the syslog-ng OSE control socket. Default value:
     /var/run/syslog-ng.ctl

     --debug or -d
	 Start syslog-ng OSE in debug mode.

     --default-modules
	 A comma-separated list of the modules that  are  loaded  automatically.
     Modules  not  loaded  automatically  can be loaded by including the @module
     <modulename> statement in the syslog-ng OSE configuration	file.  Available
     only in syslog-ng OSE version 4.1 and later.

     --enable-core
	 Enable  syslog-ng  OSE  to  write core files in case of a crash to help
     support and debugging.

     --fd-limit <number>
	 Set the minimal number of required file descriptors (fd-s).  This  sets
     how many files syslog-ng OSE can keep open simultaneously.
	 Default value: 4096.

     NOTE: This does not override the global ulimit setting of the host.

     --foreground or -F
	 Do  not  daemonize,  run  in  the foreground. When running in the fore-
     ground, syslog-ng OSE starts from the current directory (${CWD}) so it  can
     create  core  files  (normally,  syslog-ng  OSE starts from /Users/hofi/De-
     velop/Balabit/syslog-ng/build/install/var).

     --group <group> or -g <group>
	 Switch to the specified  group  after	initializing  the  configuration
     file.

     --help or -h
	 Display a brief help message.

     --module-registry
	 Display the list and description of the available modules.

     NOTE:  Not  all  of  these  modules are loaded automatically, only the ones
     specified in the --default-modules option. Available only in syslog-ng  OSE
     4.0 and later.

     --no-caps
	 Run  syslog-ng OSE as root, without capability-support. This is the de-
     fault behavior. On Linux, it is possible to run syslog-ng OSE  as	non-root
     with  capability-support  if  syslog-ng  OSE  was	compiled  with the --en-
     able-linux-caps option enabled. (Run syslog-ng  --version	to  display  the
     list of enabled build parameters.)
	 To run syslog-ng OSE with specific capabilities, use the --caps option.

     --persist-file <persist-file> or -R <persist-file>
	 Set  the  path and name of the syslog-ng.persist file where the persis-
     tent options and data are stored.

     --pidfile <pidfile> or -p <pidfile>
	 Set path to the PID file where the pid of the main process is stored.

     --preprocess-into <output-file>
	 After processing the configuration file and  resolving  included  files
     and  variables, write the resulting configuration into the specified output
     file. Available only in syslog-ng OSE 4.0 and later.

     --process-mode <mode>
	 Sets how to run syslog-ng OSE: in the foreground (mainly used	for  de-
     bugging), in the background as a daemon, or in safe-background mode. By de-
     fault,  syslog-ng OSE runs in safe-background mode. This mode creates a su-
     pervisor process called supervising syslog-ng OSE, that restarts  syslog-ng
     OSE if it crashes.

     --stderr or -e
	 Log  internal	messages of syslog-ng OSE to stderr. Mainly used for de-
     bugging purposes in conjunction with the --foreground option. If not speci-
     fied, syslog-ng OSE will log such messages to its internal source.

     --syntax-only or -s
	 Verify that the configuration file is syntactically correct and exit.

     --user <user> or -u <user>
	 Switch to the specified user after initializing the configuration  file
     (and optionally chrooting).

     NOTE:  It	is not possible to reload the syslog-ng OSE configuration if the
     specified user has no privilege to create the /dev/log file.

     --verbose or -v
	 Enable verbose logging used to troubleshoot syslog-ng OSE.

     --version or -V
	 Display version number and compilation information, and also  the  list
     and short description of the available modules. For detailed description of
     the available modules, see the --module-registry option.

     NOTE:  Not  all  of  these  modules are loaded automatically, only the ones
     specified in the --default-modules option.

     --worker-threads
	 Sets the number of worker threads syslog-ng OSE can use, including  the
     main syslog-ng OSE thread.
	 See the syslog-ng OSE Administrator Guide[1] for details.

     NOTE: Certain operations in syslog-ng OSE can use threads that are not lim-
     ited  by  this  option.  This setting has effect only when syslog-ng OSE is
     running in multithreaded mode. Available only  in	syslog-ng  OSE	4.0  and
     later.

FILES
     /Users/hofi/Develop/Balabit/syslog-ng/build/install/

     /Users/hofi/Develop/Balabit/syslog-ng/build/install/etc/syslog-ng.conf

SEE ALSO
     syslog-ng.conf(5)

     NOTE:  If	you experience any problems or need help with syslog-ng OSE, see
     the syslog-ng OSE Administration Guide[1], or visit the syslog-ng OSE mail-
     ing list[2].  For news and notifications about  syslog-ng	OSE,  visit  the
     syslog-ng OSE blogs[3].

AUTHOR
     This  manual  page  was  generated  from  the  syslog-ng OSE Administration
     Guide[1], which was written by several contributors to whom  we'd	like  to
     extend our sincere thanks.

COPYRIGHT
NOTES
     [1] syslog-ng OSE Administration Guide
	 <https://syslog-ng.github.io/admin-guide/README>

     [2] syslog-ng OSE mailing list
	 <https://lists.balabit.hu/mailman/listinfo/syslog-ng>

     [3] syslog-ng OSE blogs
	 <https://syslog-ng.com/blog/>

4.10.2				18 December 2025		    syslog-ng(8)

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