2.11BSD#431 - /usr/man/cat3/syslog.0

SYSLOG(3)	    UNIX Programmer's Manual		SYSLOG(3)


NAME
     syslog , vsyslog , openlog , closelog , setlogmask - control
     system log

SYNOPSIS
     #include <syslog.h>
     #include <varargs.h>

     void syslog(priority, message, ...);
     int priority;
     char *message;

     void vsyslog(priority, message, args);
     int priority;
     char *message;
     va_list args;

     void openlog(ident, logopt, facility);
     char *ident;
     int logopt;
     int facility;

     void closelog();

     int setlogmask(maskpri);
     int maskpri;

DESCRIPTION
     The syslog() function writes message to the system message
     logger.  The message is then written to the system console,
     log files, logged-in users, or forwarded to other machines
     as appropriate. (See syslogd(8)).

     The message is identical to a printf(3) format string,
     except that %m is replaced by the current error message as
     denoted by the global variable errno.  See strerror(3)).  A
     trailing newline is added if none is present.

     The vsyslog() function is an alternate form in which the
     arguments have already been captured using the variable-
     length argument facilities of varargs(3).

     The message is tagged with priority.  Priorities are encoded
     as a facility and a level.  The facility describes the part
     of the system generating the message.  The level is selected
     from the following ordered (high to low) list:

     LOG_EMERG	     A panic condition.  This is normally broad-
		     cast to all users.

     LOG_ALERT	     A condition that should be corrected immedi-
		     ately, such as a corrupted system database.


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SYSLOG(3)	    UNIX Programmer's Manual		SYSLOG(3)


     LOG_CRIT	     Critical conditions, e.g., hard device
		     errors.

     LOG_ERR	     Errors.

     LOG_WARNING     Warning messages.

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

     LOG_INFO	     Informational messages.

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

     The openlog() function provides for more specialized pro-
     cessing of the messages sent by syslog() and vsyslog().  The
     parameter ident is a string that will be prepended to every
     message.  The logopt argument is a bit field specifying log-
     ging options, which is formed by OR'ing one or more of the
     following values:

     LOG_CONS	    If syslog cannot pass the message to syslogd
		    it will attempt to write the message to the
		    console (/dev/console).

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

     LOG_PERROR     Write the message to standard error output as
		    well to the system log.

     LOG_PID	    Log the process id with each message: useful
		    for identifying instantiations of daemons.

     The facility parameter encodes a default facility to be
     assigned to all messages that do not have an explicit facil-
     ity encoded:

     LOG_AUTH	    The authorization system: login(1), su(1),
		    getty(8), etc.

     LOG_AUTHPRIV   The same as LOG_AUTH , but logged to a file
		    readable only by selected individuals.

     LOG_CRON	    The clock daemon.

     LOG_DAEMON     System daemons, such as routed(8), that are
		    not provided for explicitly by other


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SYSLOG(3)	    UNIX Programmer's Manual		SYSLOG(3)


		    facilities.

     LOG_KERN	    Messages generated by the kernel.  These can-
		    not be generated by any user processes.

     LOG_LPR	    The line printer spooling system: lpr(1),
		    lpc(8), lpd(8), etc.

     LOG_MAIL	    The mail system.

     LOG_NEWS	    The network news system.

     LOG_SYSLOG     Messages generated internally by syslogd(8).

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

     LOG_UUCP	    The uucp system.

     LOG_LOCAL0     Reserved for local use.  Similarly for
		    LOG_LOCAL1 through LOG_LOCAL7.

     The closelog function can be used to close the log file.

     The setlogmask function sets the log priority mask to
     maskpri and returns the previous mask.  Calls to syslog with
     a priority not set in maskpri are rejected.  The mask for an
     individual priority pri is calculated by the macro
     LOG_MASK(pri).  The mask for all priorities up to and
     including toppri is given by the macro LOG_UPTO(toppri).
     The default allows all priorities to be logged.

RETURN VALUES
     The routines closelog(), openlog(), syslog() and vsyslog()
     return no value.

     The routine setlogmask() always returns the previous log
     mask level.

EXAMPLES
	     syslog(LOG_ALERT, "who: internal error 23");

	     openlog("ftpd", LOG_PID, LOG_DAEMON);
	     setlogmask(LOG_UPTO(LOG_ERR)); syslog(LOG_INFO,
	     "Connection from host %d", CallingHost);

	     syslog(LOG_INFO|LOG_LOCAL2, "foobar error: %m");

SEE ALSO
     logger(1), syslogd(8)


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SYSLOG(3)	    UNIX Programmer's Manual		SYSLOG(3)


BUGS
     Under 2.11BSD the logfile /usr/adm/messages is used if a non
     networking kernel has been booted.  That file must be publi-
     cally writeable in this case.

HISTORY
     These functions appeared in 4.2BSD.


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