Sys::Syslog - Perl interface to the UNIX syslog(3) calls
Version 0.12
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;
Sys::Syslog is an interface to the UNIX syslog(3) program. Call syslog() with a string priority and a list of printf() args just like syslog(3).
Sys::Syslog
syslog(3)
syslog()
printf()
Sys::Syslog exports the following Exporter tags:
Exporter
:standard exports the standard syslog(3) functions:
:standard
openlog closelog setlogmask syslog
:extended exports the Perl specific functions for syslog(3):
:extended
setlogsock
:macros exports the symbols corresponding to most of your syslog(3) macros. See "CONSTANTS" for the supported constants and their meaning.
:macros
By default, Sys::Syslog exports the symbols from the :standard tag.
Opens the syslog. $ident is prepended to every message. $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 available in your system. Facility can be given as a string or a numeric macro.
$ident
$logopt
pid
ndelay
nowait
cons
$facility
LOG_USER
LOG_LOCAL0
This function will croak if it can't connect to the syslog daemon.
Note that openlog() now takes three arguments, just like openlog(3).
openlog()
openlog(3)
You should use openlog() before calling syslog().
Options
ndelay - Open the connection immediately (normally, the connection is opened when the first message is logged).
nowait - Don't wait for child processes that may have been created while logging the message. (The GNU C library does not create a child process, so this option has no effect on Linux.)
pid - Include PID with each message.
Examples
Open the syslog with options ndelay and pid, and with facility LOCAL0:
LOCAL0
openlog($name, "ndelay,pid", "local0");
Same thing, but this time using the macro corresponding to LOCAL0:
openlog($name, "ndelay,pid", LOG_LOCAL0);
If $priority permits, logs $message or sprintf($format, @args) with the addition that %m in $message or $format is replaced with "$!" (the latest error message).
$priority
$message
sprintf($format, @args)
%m
$format
"$!"
$priority can specify a level, or a level and a facility. 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 ":".
":"
syslog("info", $message); # informational level syslog(LOG_INFO, $message); # informational level syslog("info|local0", $message); # information level, Local0 facility syslog(LOG_INFO|LOG_LOCAL0, $message); # information level, Local0 facility
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", $message) instead of syslog($priority, $message). This protects against hostile formatting sequences that might show up if $message contains tainted data.
sprintf()
syslog($priority, "%s", $message)
syslog($priority, $message)
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.
$mask_priority
Only log errors:
setlogmask(LOG_ERR);
Log critical messages, errors and warnings:
setlogmask(LOG_CRIT|LOG_ERR|LOG_WARNING);
Sets the socket type to be used for the next call to openlog() or syslog() and returns true on success, undef on failure.
undef
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 getservbyname(). "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().
"unix"
_PATH_LOG
"stream"
"inet"
tcp
udp
getservbyname()
"tcp"
"udp"
"console"
"cons"
A reference to an array can also be passed as the 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.
unix
stream
console
Giving an invalid value for $sock_type will croak.
$sock_type
Closes the log file and return true on success.
openlog($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');
LOG_AUTH - security/authorization messages
LOG_AUTH
LOG_AUTHPRIV - security/authorization messages (private)
LOG_AUTHPRIV
LOG_CRON - clock daemon (cron and at)
LOG_CRON
LOG_DAEMON - system daemons without separate facility value
LOG_DAEMON
LOG_FTP - ftp daemon
LOG_FTP
LOG_KERN - kernel messages
LOG_KERN
LOG_LOCAL0 through LOG_LOCAL7 - reserved for local use
LOG_LOCAL7
LOG_LPR - line printer subsystem
LOG_LPR
LOG_MAIL - mail subsystem
LOG_MAIL
LOG_NEWS - USENET news subsystem
LOG_NEWS
LOG_SYSLOG - messages generated internally by syslogd
LOG_SYSLOG
LOG_USER (default) - generic user-level messages
LOG_UUCP - UUCP subsystem
LOG_UUCP
LOG_EMERG - system is unusable
LOG_EMERG
LOG_ALERT - action must be taken immediately
LOG_ALERT
LOG_CRIT - critical conditions
LOG_CRIT
LOG_ERR - error conditions
LOG_ERR
LOG_WARNING - warning conditions
LOG_WARNING
LOG_NOTICE - normal, but significant, condition
LOG_NOTICE
LOG_INFO - informational message
LOG_INFO
LOG_DEBUG - debug-level message
LOG_DEBUG
(F) You gave setlogsock() an invalid value for $sock_type.
setlogsock()
(F) syslog() failed to connect to the specified socket.
(W) You asked setlogsock() to use a stream socket, but the given path is not writable.
(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.
(W) You asked setlogsock() to use a TCP socket, but the service is not available on the system.
(F) You forgot to give syslog() the indicated argument.
(F) You specified an invalid level or facility, like LOG_KERN (which is reserved to the kernel).
(F) You specified too many levels.
(F) You specified too many facilities.
(F) You forgot to specify a level.
(W) You asked setlogsock() to use a UDP socket, but the service is not available on the system.
(W) You asked setlogsock() to use a UNIX socket, but Sys::Syslog was unable to find an appropriate an appropriate device.
Syslogging with Perl, http://lexington.pm.org/meetings/022001.html
Tom Christiansen <tchrist@perl.com> and Larry Wall <larry@wall.org>.
UNIX domain sockets added by Sean Robinson <robinson_s@sc.maricopa.edu> with support from Tim Bunce <Tim.Bunce@ig.co.uk> and the perl5-porters mailing list.
perl5-porters
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>.
constant()
Failover to different communication modes by Nick Williams <Nick.Williams@morganstanley.com>.
Extracted from core distribution for publishing on the CPAN by Sébastien Aperghis-Tramoni <sebastien@aperghis.net>.
Please report any bugs or feature requests to bug-sys-syslog at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Sys-Syslog. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
bug-sys-syslog at rt.cpan.org
You can find documentation for this module with the perldoc 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
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Sys::Syslog, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Sys::Syslog
CPAN shell
perl -MCPAN -e shell install Sys::Syslog
For more information on module installation, please visit the detailed CPAN module installation guide.