Doc/lib/libsyslog.tex

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