


Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


NAME
       Sys::Syslog - Perl interface to the UNIX syslog(3) calls

VERSION
       Version 0.13

SYNOPSIS
           use Sys::Syslog;                          # all except setlogsock(), or:
           use Sys::Syslog qw(:DEFAULT setlogsock);  # default set, plus setlogsock()
           use Sys::Syslog qw(:standard :macros);    # standard functions, plus macros

           setlogsock $sock_type;
           openlog $ident, $logopt, $facility;       # don't forget this
           syslog $priority, $format, @args;
           $oldmask = setlogmask $mask_priority;
           closelog;

DESCRIPTION
       "Sys::Syslog" is an interface to the UNIX syslog(3) pro-
       gram.  Call "syslog()" with a string priority and a list
       of "printf()" args just like syslog(3).

EXPORTS
       "Sys::Syslog" exports the following "Exporter" tags:

       o   ":standard" exports the standard syslog(3) functions:

               openlog closelog setlogmask syslog

       o   ":extended" exports the Perl specific functions for
           syslog(3):

               setlogsock

       o   ":macros" exports the symbols corresponding to most of
           your syslog(3) macros. See "CONSTANTS" for the sup-
           ported constants and their meaning.

       By default, "Sys::Syslog" exports the symbols from the
       ":standard" tag.

FUNCTIONS
       openlog($ident, $logopt, $facility)
           Opens the syslog.  $ident is prepended to every mes-
           sage.  $logopt contains zero or more of the words
           "pid", "ndelay", "nowait".  The "cons" option is
           ignored, since the failover mechanism will drop down
           to the console automatically if all other media fail.
           $facility specifies the part of the system to report
           about, for example "LOG_USER" or "LOG_LOCAL0": see
           your syslog(3) documentation for the facilities avail-
           able in your system. Facility can be given as a string
           or a numeric macro.




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Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


           This function will croak if it can't connect to the
           syslog daemon.

           Note that "openlog()" now takes three arguments, just
           like openlog(3).

           You should use openlog() before calling syslog().

           Options

           *   "ndelay" - Open the connection immediately (nor-
               mally, the connection is opened when the first
               message is logged).

           *   "nowait" - Don't wait for child processes that may
               have been created while logging the message.  (The
               GNU C library does not create a child process, so
               this option has no effect on Linux.)

           *   "pid" - Include PID with each message.

           Examples

           Open the syslog with options "ndelay" and "pid", and
           with facility "LOCAL0":

               openlog($name, "ndelay,pid", "local0");

           Same thing, but this time using the macro correspond-
           ing to "LOCAL0":

               openlog($name, "ndelay,pid", LOG_LOCAL0);

       syslog($priority, $message)
       syslog($priority, $format, @args)
           If $priority permits, logs $message or "sprintf($for-
           mat, @args)" with the addition that %m in $message or
           $format is replaced with "$!" (the latest error mes-
           sage).

           $priority can specify a level, or a level and a facil-
           ity.  Levels and facilities can be given as strings or
           as macros.

           If you didn't use "openlog()" before using "syslog()",
           "syslog()" will try to guess the $ident by extracting
           the shortest prefix of $format that ends in a ":".

           Examples

               syslog("info", $message);           # informational level
               syslog(LOG_INFO, $message);         # informational level





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Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


               syslog("info|local0", $message);        # information level, Local0 facility
               syslog(LOG_INFO|LOG_LOCAL0, $message);  # information level, Local0 facility

           Note
               "Sys::Syslog" version v0.07 and older passed the
               $message as the formatting string to "sprintf()"
               even when no formatting arguments were provided.
               If the code calling "syslog()" might execute with
               older versions of this module, make sure to call
               the function as "syslog($priority, "%s", $mes-
               sage)" instead of "syslog($priority, $message)".
               This protects against hostile formatting sequences
               that might show up if $message contains tainted
               data.

       setlogmask($mask_priority)
           Sets the log mask for the current process to
           $mask_priority and returns the old mask.  If the mask
           argument is 0, the current log mask is not modified.
           See "Levels" for the list of available levels.

           Examples

           Only log errors:

               setlogmask(LOG_ERR);

           Log critical messages, errors and warnings:

               setlogmask(LOG_CRIT|LOG_ERR|LOG_WARNING);

       setlogsock($sock_type)
       setlogsock($sock_type, $stream_location) (added in
       5.004_02)
           Sets the socket type to be used for the next call to
           "openlog()" or "syslog()" and returns true on success,
           "undef" on failure.

           A value of "unix" will connect to the UNIX domain
           socket (in some systems a character special device)
           returned by the "_PATH_LOG" macro (if your system
           defines it), or /dev/log or /dev/conslog, whatever is
           writable.  A value of 'stream' will connect to the
           stream indicated by the pathname provided as the
           optional second parameter.  (For example Solaris and
           IRIX require "stream" instead of "unix".)  A value of
           "inet" will connect to an INET socket (either "tcp" or
           "udp", tried in that order) returned by "getservby-
           name()". "tcp" and "udp" can also be given as values.
           The value "console" will send messages directly to the
           console, as for the "cons" option in the logopts in
           "openlog()".

           A reference to an array can also be passed as the



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Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


           first parameter.  When this calling method is used,
           the array should contain a list of sock_types which
           are attempted in order.

           The default is to try "tcp", "udp", "unix", "stream",
           "console".

           Giving an invalid value for $sock_type will croak.

       closelog()
           Closes the log file and return true on success.

EXAMPLES
           openlog($program, 'cons,pid', 'user');
           syslog('info', '%s', 'this is another test');
           syslog('mail|warning', 'this is a better test: %d', time);
           closelog();

           syslog('debug', 'this is the last test');

           setlogsock('unix');
           openlog("$program $$", 'ndelay', 'user');
           syslog('notice', 'fooprogram: this is really done');

           setlogsock('inet');
           $! = 55;
           syslog('info', 'problem was %m'); # %m == $! in syslog(3)

           # Log to UDP port on $remotehost instead of logging locally
           setlogsock('udp');
           $Sys::Syslog::host = $remotehost;
           openlog($program, 'ndelay', 'user');
           syslog('info', 'something happened over here');

CONSTANTS
       Facilities


       o   "LOG_AUTH" - security/authorization messages

       o   "LOG_AUTHPRIV" - security/authorization messages (pri-
           vate)

       o   "LOG_CRON" - clock daemon (cron and at)

       o   "LOG_DAEMON" - system daemons without separate facil-
           ity value

       o   "LOG_FTP" - ftp daemon

       o   "LOG_KERN" - kernel messages

       o   "LOG_LOCAL0" through "LOG_LOCAL7" - reserved for local
           use



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Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


       o   "LOG_LPR" - line printer subsystem

       o   "LOG_MAIL" - mail subsystem

       o   "LOG_NEWS" - USENET news subsystem

       o   "LOG_SYSLOG" - messages generated internally by sys-
           logd

       o   "LOG_USER" (default) - generic user-level messages

       o   "LOG_UUCP" - UUCP subsystem

       Levels


       o   "LOG_EMERG" - system is unusable

       o   "LOG_ALERT" - action must be taken immediately

       o   "LOG_CRIT" - critical conditions

       o   "LOG_ERR" - error conditions

       o   "LOG_WARNING" - warning conditions

       o   "LOG_NOTICE" - normal, but significant, condition

       o   "LOG_INFO" - informational message

       o   "LOG_DEBUG" - debug-level message

DIAGNOSTICS
       Invalid argument passed to setlogsock
           (F) You gave "setlogsock()" an invalid value for
           $sock_type.

       no connection to syslog available
           (F) "syslog()" failed to connect to the specified
           socket.

       stream passed to setlogsock, but %s is not writable
           (W) You asked "setlogsock()" to use a stream socket,
           but the given path is not writable.

       stream passed to setlogsock, but could not find any device
           (W) You asked "setlogsock()" to use a stream socket,
           but didn't provide a path, and "Sys::Syslog" was
           unable to find an appropriate one.

       tcp passed to setlogsock, but tcp service unavailable
           (W) You asked "setlogsock()" to use a TCP socket, but
           the service is not available on the system.




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Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


       syslog: expecting argument %s
           (F) You forgot to give "syslog()" the indicated argu-
           ment.

       syslog: invalid level/facility: %s
           (F) You specified an invalid level or facility, like
           "LOG_KERN" (which is reserved to the kernel).

       syslog: too many levels given: %s
           (F) You specified too many levels.

       syslog: too many facilities given: %s
           (F) You specified too many facilities.

       syslog: level must be given
           (F) You forgot to specify a level.

       udp passed to setlogsock, but udp service unavailable
           (W) You asked "setlogsock()" to use a UDP socket, but
           the service is not available on the system.

       unix passed to setlogsock, but path not available
           (W) You asked "setlogsock()" to use a UNIX socket, but
           "Sys::Syslog" was unable to find an appropriate an
           appropriate device.

SEE ALSO
       syslog(3)

       Syslogging with Perl, <http://lexington.pm.org/meet-
       ings/022001.html>

AUTHOR
       Tom Christiansen <tchrist@perl.com> and Larry Wall
       <larry@wall.org>.

       UNIX domain sockets added by Sean Robinson <robin-
       son_s@sc.maricopa.edu> with support from Tim Bunce
       <Tim.Bunce@ig.co.uk> and the "perl5-porters" mailing list.

       Dependency on syslog.ph replaced with XS code by Tom
       Hughes <tom@compton.nu>.

       Code for "constant()"s regenerated by Nicholas Clark
       <nick@ccl4.org>.

       Failover to different communication modes by Nick Williams
       <Nick.Williams@morganstanley.com>.

       Extracted from core distribution for publishing on the
       CPAN by Sebastien Aperghis-Tramoni
       <sebastien@aperghis.net>.





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Sys::Syslog(3p)  Perl Programmers Reference Guide Sys::Syslog(3p)


BUGS
       Please report any bugs or feature requests to
       "bug-sys-syslog at rt.cpan.org", or through the web inter-
       face at <http://rt.cpan.org/NoAuth/Report-
       Bug.html?Queue=Sys-Syslog>.  I will be notified, and then
       you'll automatically be notified of progress on your bug
       as I make changes.

SUPPORT
       You can find documentation for this module with the perl-
       doc command.

           perldoc Sys::Syslog

       You can also look for information at:

       * AnnoCPAN: Annotated CPAN documentation
           <http://annocpan.org/dist/Sys-Syslog>

       * CPAN Ratings
           <http://cpanratings.perl.org/d/Sys-Syslog>

       * RT: CPAN's request tracker
           <http://rt.cpan.org/NoAuth/Bugs.html?Dist=Sys-Syslog>

       * Search CPAN
           <http://search.cpan.org/dist/Sys-Syslog>

LICENSE
       This program is free software; you can redistribute it
       and/or modify it under the same terms as Perl itself.


























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