trusty (3) syslog.3.gz

NAME

       closelog, openlog, syslog - send messages to the system logger

SYNOPSIS

       #include <syslog.h>

       void openlog( char *ident, int option, int  facility)

       void syslog( int priority, char *format, ...)

       void closelog( void )

DESCRIPTION

       closelog()  closes  the  descriptor  being  used to write to the system logger.  The use of closelog() is
       optional.

       openlog() opens a connection to the system logger for a program.  The string pointed to by ident is added
       to  each  message, and is typically set to the program name.  Values for option and facility are given in
       the next section.  The use of openlog() is optional; It will  automatically  be  called  by  syslog()  if
       necessary, in which case ident will default to NULL.

       syslog()  generates a log message, which will be distributed by syslogd(8).  priority is a combination of
       the facility and the level, values for which are given in the next section.  The remaining arguments  are
       a format, as in printf(3) and any arguments required by the format, except that the two character %m will
       be replaced by the error message string (strerror) corresponding to the present value of errno.

PARAMETERS

       This section lists the parameters used to set the values of option, facility, and priority.

   option
       The option argument to openlog() is an OR of any of these:

       LOG_CONS
              write directly to system console if there is an error while sending to system logger

       LOG_NDELAY
              open the connection immediately (normally, the connection is opened  when  the  first  message  is
              logged)

       LOG_PERROR
              print to stderr as well

       LOG_PID
              include PID with each message

   facility
       The  facility  argument  is  used  to specify what type of program is logging the message.  This lets the
       configuration file specify that messages from different facilities will be handled differently.

       LOG_AUTH
              security/authorization messages (DEPRECATED Use LOG_AUTHPRIV instead)

       LOG_AUTHPRIV
              security/authorization messages (private)

       LOG_CRON
              clock daemon (cron and at)

       LOG_DAEMON
              other system daemons

       LOG_KERN
              kernel messages

       LOG_LOCAL0 through LOG_LOCAL7
              reserved for local use

       LOG_LPR
              line printer subsystem

       LOG_MAIL
              mail subsystem

       LOG_NEWS
              USENET news subsystem

       LOG_SYSLOG
              messages generated internally by syslogd

       LOG_USER(default)
              generic user-level messages

       LOG_UUCP
              UUCP subsystem

   level
       This determines the importance of the message.  The levels are, in order of decreasing importance:

       LOG_EMERG
              system is unusable

       LOG_ALERT
              action must be taken immediately

       LOG_CRIT
              critical conditions

       LOG_ERR
              error conditions

       LOG_WARNING
              warning conditions

       LOG_NOTICE
              normal, but significant, condition

       LOG_INFO
              informational message

       LOG_DEBUG
              debug-level message

HISTORY

       A syslog function call appeared in BSD 4.2.

SEE ALSO

       logger(1), syslog.conf(5), syslogd(8)