Sys::Syslog - Perl interface to the UNIX syslog(3) calls
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
Sys::Syslog exports the following
:standard exports the standard
openlog closelog setlogmask syslog
:extended exports the Perl specific functions for
:macros exports the symbols corresponding to most of your
syslog(3) macros. See "CONSTANTS" for the supported constants and their meaning.
Sys::Syslog exports the symbols from the
Opens the syslog.
$ident is prepended to every message.
$logopt contains zero or more of the words
cons option is ignored, since the failover mechanism will drop down to the console automatically if all other media fail.
$facility specifies the part of the system to report about, for example
LOG_LOCAL0: see your
syslog(3) documentation for the facilities available in your system. Facility can be given as a string or a numeric macro.
This function will croak if it can't connect to the syslog daemon.
openlog() now takes three arguments, just like
You should use openlog() before calling syslog().
ndelay - Open the connection immediately (normally, the connection is opened when the first message is logged).
nowait - Don't wait for child processes that may have been created while logging the message. (The GNU C library does not create a child process, so this option has no effect on Linux.)
pid - Include PID with each message.
Open the syslog with options
pid, and with facility
openlog($name, "ndelay,pid", "local0");
Same thing, but this time using the macro corresponding to
openlog($name, "ndelay,pid", LOG_LOCAL0);
$priority permits, logs
sprintf($format, @args) with the addition that
%m in $message or
$format is replaced with
"$!" (the latest error message).
$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() 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.
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.
Only log errors:
Log critical messages, errors and warnings:
Sets the socket type to be used for the next call to
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
udp, tried in that order) returned by
"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
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
Giving an invalid value for
$sock_type will croak.
Closes the log file and return true on success.
openlog($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_AUTHPRIV - security/authorization messages (private)
LOG_CRON - clock daemon (cron and at)
LOG_DAEMON - system daemons without separate facility value
LOG_FTP - ftp daemon
LOG_KERN - kernel messages
LOG_LOCAL7 - reserved for local use
LOG_LPR - line printer subsystem
LOG_MAIL - mail subsystem
LOG_NEWS - USENET news subsystem
LOG_SYSLOG - messages generated internally by syslogd
LOG_USER (default) - generic user-level messages
LOG_UUCP - UUCP subsystem
LOG_EMERG - system is unusable
LOG_ALERT - action must be taken immediately
LOG_CRIT - critical conditions
LOG_ERR - error conditions
LOG_WARNING - warning conditions
LOG_NOTICE - normal, but significant, condition
LOG_INFO - informational message
LOG_DEBUG - debug-level message
(F) You gave
setlogsock() an invalid value for
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 <firstname.lastname@example.org> and Larry Wall <email@example.com>.
UNIX domain sockets added by Sean Robinson <firstname.lastname@example.org> 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 <email@example.com>.
constant()s regenerated by Nicholas Clark <firstname.lastname@example.org>.
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 <email@example.com>.
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.
You can find documentation for this module with the perldoc command.
You can also look for information at:
AnnoCPAN: Annotated CPAN documentation
RT: CPAN's request tracker
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.