PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       syslog.h — definitions for system error logging

SYNOPSIS

       #include <syslog.h>

DESCRIPTION

       The <syslog.h> header shall define the following symbolic constants, zero or more of which
       may be OR'ed together to form the logopt option of openlog():

       LOG_PID       Log the process ID with each message.

       LOG_CONS      Log to the system console on error.

       LOG_NDELAY    Connect to syslog daemon immediately.

       LOG_ODELAY    Delay open until syslog() is called.

       LOG_NOWAIT    Do not wait for child processes.

       The <syslog.h> header shall define  the  following  symbolic  constants  for  use  as  the
       facility argument to openlog():

       LOG_KERN      Reserved for message generated by the system.

       LOG_USER      Message generated by a process.

       LOG_MAIL      Reserved for message generated by mail system.

       LOG_NEWS      Reserved for message generated by news system.

       LOG_UUCP      Reserved for message generated by UUCP system.

       LOG_DAEMON    Reserved for message generated by system daemon.

       LOG_AUTH      Reserved for message generated by authorization daemon.

       LOG_CRON      Reserved for message generated by clock daemon.

       LOG_LPR       Reserved for message generated by printer system.

       LOG_LOCAL0    Reserved for local use.

       LOG_LOCAL1    Reserved for local use.

       LOG_LOCAL2    Reserved for local use.

       LOG_LOCAL3    Reserved for local use.

       LOG_LOCAL4    Reserved for local use.

       LOG_LOCAL5    Reserved for local use.

       LOG_LOCAL6    Reserved for local use.

       LOG_LOCAL7    Reserved for local use.

       The  <syslog.h>  header  shall  define  the  following macros for constructing the maskpri
       argument to setlogmask().  The following macros expand to an expression of type  int  when
       the argument pri is an expression of type int:

       LOG_MASK(pri) A mask for priority pri.

       The  <syslog.h>  header  shall  define  the  following  symbolic  constants for use as the
       priority argument of syslog():

       LOG_EMERG     A panic condition was reported to all processes.

       LOG_ALERT     A condition that should be corrected immediately.

       LOG_CRIT      A critical condition.

       LOG_ERR       An error message.

       LOG_WARNING   A warning message.

       LOG_NOTICE    A condition requiring special handling.

       LOG_INFO      A general information message.

       LOG_DEBUG     A message useful for debugging programs.

       The following shall be declared as functions and may also be defined as  macros.  Function
       prototypes shall be provided.

           void  closelog(void);
           void  openlog(const char *, int, int);
           int   setlogmask(int);
           void  syslog(int, const char *, ...);

       The following sections are informative.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The System Interfaces volume of POSIX.1‐2017, closelog()

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1-2017, Standard for Information Technology -- Portable  Operating  System  Interface
       (POSIX),  The  Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by
       the Institute of Electrical and Electronics Engineers, Inc and The  Open  Group.   In  the
       event  of  any  discrepancy  between this version and the original IEEE and The Open Group
       Standard, the original IEEE and The Open Group  Standard  is  the  referee  document.  The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .