syslog(3C)																syslog(3C)

NAME

       syslog(), openlog(), closelog(), setlogmask() - control system log

SYNOPSIS

   Remarks
       The ANSI C "" construct denotes a variable length argument list whose optional [or required] members are given in the associated comment

DESCRIPTION

       writes a message onto the system log maintained by
		      (see  syslogd(1M)).   The message is tagged with priority.  The message is similar to a printf(3S) format string except that
		      is replaced by the error message associated with the current value of A trailing newline is added if needed.

		      This message is read by and written to the system console, log files, selected users' terminals, or forwarded to on  another
		      host as appropriate.

		      priority is encoded as the logical OR of a level and a facility.	The level signifies the urgency of the message, and facil-
		      ity signifies the subsystem generating the message.  facility can be encoded explicitly in priority, or a  default  facility
		      can be set with (see below).

		      level is selected from an ordered list:

			   A panic condition.  This is normally broadcast to all users.

			   A condition that should be corrected immediately,
					       such as a corrupted system database.

			   Critical conditions, such as hard device errors.

			   Errors.

			   Warning messages.

			   Conditions that are not error conditions,
					       but should possibly be handled specially.

			   Informational messages.

			   Messages that contain information
					       normally of use only when debugging a program.

		      does not log a message that does not have a level set.

		      If cannot pass the message to it attempts to write the message on if the option is set (see below).

       can be called to initialize the log file,
		      if  special processing is needed.  ident is a string that precedes every message.  logopt is a mask of bits, logically OR'ed
		      together, indicating logging options.  The values for logopt are:

			   Log the process     ID with each message; useful for identifying instantiations of daemons.

			   Force writing messages to the console if unable to send it to
					       This option is safe to use in daemon processes that have  no  controlling  terminal  because  forks
					       before opening the console.

			   Open the connection to
					       immediately.   Normally, the open is delayed until the first message is logged.	This is useful for
					       programs that need to manage the order in which file descriptors are allocated.

			   Do not wait for children forked to log messages on the console.
					       This option should be used by processes that enable notification of child termination  via  because
					       might otherwise block, waiting for a child whose exit status has already been collected.

		      facility	encodes  a  default  facility  to  be  assigned  to all messages written subsequently by with no explicit facility
		      encoded.

			   Messages generated by the kernel.
					       These cannot be generated by any user processes.

			   Messages generated by random user processes.
					       This is the default facility identifier if none is specified.

			   The mail system.

			   System daemons, such as
					       inetd(1M), ftpd(1M), etc.

			   The authorization system:
					       login(1), su(1), getty(1M), etc.

			   Messages generated internally by
					       daemon.

			   The line printer spooling system:
					       lp(1), lpsched(1M), etc.

			   Messages generated by the
					       system.

			   Messages generated by the UUCP system.

			   Messages generated by the CRON daemon.

			   Reserved for local use.
					       Similarly for through

		      facility and level uses an encoded code for logging in message.  The encoded code for facility and level are as follows.

       closes the log file.

       sets the log priority mask to
		      maskpri and returns the previous mask.  Calls to with a priority not set in maskpri are rejected.  The mask for an  individ-
		      ual  priority  pri is calculated by the macro ; the mask for all priorities up to and including toppri is given by the macro
		      (toppri).  By default, all priorities are logged.

ERRORS

       fails if any of the following conditions are encountered:

	      The named pipe is blocked for writing.

	      The named pipe bold) could not be opened successfully.

EXAMPLES

       logs a message regarding some sort of unexpected and serious error:

       uses to arrange to log its process ID, to log to the console if necessary, and to log in the name of the daemon facility:

       Arrange to log messages only at levels and lower:

       Typical usage of to log a connection:

       If the facility has not been set with it defaults to

       Explicitly set the facility for this message:

WARNINGS

       A call to has no effect unless the syslog daemon is running (see syslogd(1M)).  does not copy and store the  ident  string  internally;	it
       stores  only  a character pointer.  Therefore it is the responsibility of the programmer to make sure that the ident argument points to the
       correct string until the log file is closed.

AUTHOR

       was developed by the University of California, Berkeley.

SEE ALSO

       logger(1), syslogd(1M), thread_safety(5).

																	syslog(3C)