Doc/lib/libsyslog.tex

   1 \section{\module{syslog} ---
   2          \UNIX{} syslog library routines}
   3
   4 \declaremodule{builtin}{syslog}
   5   \platform{Unix}
   6 \modulesynopsis{An interface to the \UNIX\ syslog library routines.}
   7
   8
   9 This module provides an interface to the \UNIX{} \code{syslog} library
  10 routines.  Refer to the \UNIX{} manual pages for a detailed description
  11 of the \code{syslog} facility.
  12
  13 The module defines the following functions:
  14
  15
  16 \begin{funcdesc}{syslog}{\optional{priority,} message}
  17 Send the string \var{message} to the system logger.  A trailing
  18 newline is added if necessary.  Each message is tagged with a priority
  19 composed of a \var{facility} and a \var{level}.  The optional
  20 \var{priority} argument, which defaults to \constant{LOG_INFO},
  21 determines the message priority.  If the facility is not encoded in
  22 \var{priority} using logical-or (\code{LOG_INFO | LOG_USER}), the
  23 value given in the \function{openlog()} call is used.
  24 \end{funcdesc}
  25
  26 \begin{funcdesc}{openlog}{ident\optional{, logopt\optional{, facility}}}
  27 Logging options other than the defaults can be set by explicitly
  28 opening the log file with \function{openlog()} prior to calling
  29 \function{syslog()}.  The defaults are (usually) \var{ident} =
  30 \code{'syslog'}, \var{logopt} = \code{0}, \var{facility} =
  31 \constant{LOG_USER}.  The \var{ident} argument is a string which is
  32 prepended to every message.  The optional \var{logopt} argument is a
  33 bit field - see below for possible values to combine.  The optional
  34 \var{facility} argument sets the default facility for messages which
  35 do not have a facility explicitly encoded.
  36 \end{funcdesc}
  37
  38 \begin{funcdesc}{closelog}{}
  39 Close the log file.
  40 \end{funcdesc}
  41
  42 \begin{funcdesc}{setlogmask}{maskpri}
  43 Set the priority mask to \var{maskpri} and return the
  44 previous mask value.  Calls to \function{syslog()} with a priority
  45 level not set in \var{maskpri} are ignored.  The default is to log all
  46 priorities.  The function \code{LOG_MASK(\var{pri})} calculates the
  47 mask for the individual priority \var{pri}.  The function
  48 \code{LOG_UPTO(\var{pri})} calculates the mask for all priorities up
  49 to and including \var{pri}.
  50 \end{funcdesc}
  51
  52
  53 The module defines the following constants:
  54
  55 \begin{description}
  56
  57 \item[Priority levels (high to low):]
  58
  59 \constant{LOG_EMERG}, \constant{LOG_ALERT}, \constant{LOG_CRIT},
  60 \constant{LOG_ERR}, \constant{LOG_WARNING}, \constant{LOG_NOTICE},
  61 \constant{LOG_INFO}, \constant{LOG_DEBUG}.
  62
  63 \item[Facilities:]
  64
  65 \constant{LOG_KERN}, \constant{LOG_USER}, \constant{LOG_MAIL},
  66 \constant{LOG_DAEMON}, \constant{LOG_AUTH}, \constant{LOG_LPR},
  67 \constant{LOG_NEWS}, \constant{LOG_UUCP}, \constant{LOG_CRON} and
  68 \constant{LOG_LOCAL0} to \constant{LOG_LOCAL7}.
  69
  70 \item[Log options:]
  71
  72 \constant{LOG_PID}, \constant{LOG_CONS}, \constant{LOG_NDELAY},
  73 \constant{LOG_NOWAIT} and \constant{LOG_PERROR} if defined in
  74 \code{<syslog.h>}.
  75
  76 \end{description}