use Unix::Syslog qw(:macros); # Syslog macros use Unix::Syslog qw(:subs); # Syslog functions openlog $ident, $option, $facility; syslog $priority, $format, @formatargs; closelog; $oldmask = setlogmask $mask_priority;
In contrary to Sys::Syslog(3), this modules does not open a network connection to send the messages. This can help you to avoid opening security holes in your computer (see ``FAQ'').
The subs imported by the tag "macros" are simply wrappers around the most important "#defines" in your system's C header file syslog.h. The macros return integer values that are used to specify options, facilities and priorities in a more or less portable way. They also provide general information about your local syslog mechanism. Check syslog(3) and your local syslog.h for information about the macros, options and facilities available on your system.
The following functions are provided:
$priority is an integer value that specifies the priority of the message. Alternatively $priority can be the ORed value of a priority and a facility. In that case a previously selected facility will be overridden.
In the case that "syslog()" is called without calling "openlog()" first and priority does not specify both a priority and a facility, a default facility will be used. This behaviour is most likely system dependent and the user should not rely on any particular value in that case.
$format is a format string in the style of printf(3). Additionally to the usual printf directives %m can be specified in the string. It will be replaced implicitly by the contents of the Perl variable $! ($ERRNO). @formatargs is a list of values that the format directives will be replaced with subsequently.
NOTE: The behaviour of this module is system dependent. It is highly recommended to consult your system manual for available macros and the behaviour of the provided functions.
Generate log message of specified priority using a printf-type formatted
"syslog LOG_INFO, "This is message number %d", 42;"
Set log priority mask to block all messages but those of priority
"$oldmask = setlogmask(LOG_MASK(LOG_DEBUG))"
Set log priority mask to block all messages with a higher priority than
"$oldmask = setlogmask(LOG_UPTO(LOG_ERR))"
Close channel to syslogd:
Sys::Syslog always opens a network connection to the syslog service. At least on Linux systems this may lead to some trouble, because
OS-independent, some sysadmins may run a firewall on their network that blocks connections to port 514/udp.
Peter Stamfest <email@example.com> pointed out some other advantages of Unix::Syslog, I didn't came across my self.
Yes! In contrary to Unix::Syslog, Sys::Syslog works even if you don't have a syslog daemon running on your system as long as you are connected to a log host via a network and have access to the syslog.h header file of your log host to generate the initial files for Sys::Syslog (see Sys::Syslog(3) for details). Unix::Syslog only logs to your local syslog daemon which in turn may be configured to distribute the message over the network.
Currently not. Sys::Syslog requires strings to specify many of the arguments to the functions, while Unix::Syslog uses numeric constants accessed via macros as defined in syslog.h. Although the strings used by Sys::Syslog are also defined in syslog.h, it seems that most people got used to the numeric arguments. I will implement the string based calls if there are enough people ($min_people > 10**40) complaining about the lack of compatibility.