3 use warnings::register;
5 use Fcntl qw(O_WRONLY);
7 use POSIX qw(strftime setlocale LC_TIME);
17 standard => [qw(openlog syslog closelog setlogmask)],
18 extended => [qw(setlogsock)],
22 LOG_ALERT LOG_CRIT LOG_DEBUG LOG_EMERG LOG_ERR
23 LOG_INFO LOG_NOTICE LOG_WARNING
28 LOG_AUTH LOG_AUTHPRIV LOG_CRON LOG_DAEMON LOG_FTP LOG_KERN
29 LOG_LOCAL0 LOG_LOCAL1 LOG_LOCAL2 LOG_LOCAL3 LOG_LOCAL4
30 LOG_LOCAL5 LOG_LOCAL6 LOG_LOCAL7 LOG_LPR LOG_MAIL LOG_NEWS
31 LOG_SYSLOG LOG_USER LOG_UUCP
33 # Mac OS X specific facilities
34 qw( LOG_INSTALL LOG_LAUNCHD LOG_NETINFO LOG_RAS LOG_REMOTEAUTH ),
35 # modern BSD specific facilities
36 qw( LOG_CONSOLE LOG_NTP LOG_SECURITY ),
37 # IRIX specific facilities
38 qw( LOG_AUDIT LOG_LFMT ),
42 LOG_CONS LOG_PID LOG_NDELAY LOG_NOWAIT LOG_ODELAY LOG_PERROR
47 LOG_FACMASK LOG_NFACILITIES LOG_PRIMASK
54 @{$EXPORT_TAGS{standard}},
58 @{$EXPORT_TAGS{extended}},
59 @{$EXPORT_TAGS{macros}},
64 XSLoader::load('Sys::Syslog', $VERSION);
68 push @ISA, 'DynaLoader';
69 bootstrap Sys::Syslog $VERSION;
77 use vars qw($host); # host to send syslog messages to (see notes at end)
82 use vars qw($facility);
83 my $connected = 0; # flag to indicate if we're connected or not
84 my $syslog_send; # coderef of the function used to send messages
85 my $syslog_path = undef; # syslog path for "stream" and "unix" mechanisms
86 my $syslog_xobj = undef; # if defined, holds the external object used to send messages
87 my $transmit_ok = 0; # flag to indicate if the last message was transmited
88 my $current_proto = undef; # current mechanism used to transmit messages
89 my $ident = ''; # identifiant prepended to each message
90 $facility = ''; # current facility
91 my $maskpri = LOG_UPTO(&LOG_DEBUG); # current log mask
101 # Default is now to first use the native mechanism, so Perl programs
102 # behave like other normal Unix programs, then try other mechanisms.
103 my @connectMethods = qw(native tcp udp unix pipe stream console);
104 if ($^O =~ /^(freebsd|linux)$/) {
105 @connectMethods = grep { $_ ne 'udp' } @connectMethods;
109 # use EventLog on Win32
110 my $is_Win32 = $^O =~ /Win32/i;
112 # some applications are trying to be too smart
113 # yes I'm speaking of YOU, SpamAssassin, grr..
114 local($SIG{__DIE__}, $SIG{__WARN__}, $@);
116 if (eval "use Sys::Syslog::Win32; 1") {
117 unshift @connectMethods, 'eventlog';
124 my @defaultMethods = @connectMethods;
125 my @fallbackMethods = ();
127 # coderef for a nicer handling of errors
128 my $err_sub = $options{nofatal} ? \&warnings::warnif : \&croak;
132 # This AUTOLOAD is used to 'autoload' constants from the constant()
136 ($constname = $AUTOLOAD) =~ s/.*:://;
137 croak "Sys::Syslog::constant() not defined" if $constname eq 'constant';
138 my ($error, $val) = constant($constname);
139 croak $error if $error;
141 *$AUTOLOAD = sub { $val };
147 ($ident, my $logopt, $facility) = @_;
150 $ident ||= basename($0) || getlogin() || getpwuid($<) || 'syslog';
152 $facility ||= LOG_USER();
154 for my $opt (split /\b/, $logopt) {
155 $options{$opt} = 1 if exists $options{$opt}
158 $err_sub = $options{nofatal} ? \&warnings::warnif : \&croak;
159 return 1 unless $options{ndelay};
164 $facility = $ident = '';
169 my $oldmask = $maskpri;
170 $maskpri = shift unless $_[0] == 0;
176 $syslog_path = shift;
177 disconnect_log() if $connected;
179 @fallbackMethods = ();
180 @connectMethods = @defaultMethods;
182 if (ref $setsock eq 'ARRAY') {
183 @connectMethods = @$setsock;
185 } elsif (lc $setsock eq 'stream') {
186 if (not defined $syslog_path) {
187 my @try = qw(/dev/log /dev/conslog);
189 if (length &_PATH_LOG) { # Undefined _PATH_LOG is "".
190 unshift @try, &_PATH_LOG;
200 if (not defined $syslog_path) {
201 warnings::warnif "stream passed to setlogsock, but could not find any device";
206 if (not -w $syslog_path) {
207 warnings::warnif "stream passed to setlogsock, but $syslog_path is not writable";
210 @connectMethods = qw(stream);
213 } elsif (lc $setsock eq 'unix') {
214 if (length _PATH_LOG() || (defined $syslog_path && -w $syslog_path)) {
215 $syslog_path = _PATH_LOG() unless defined $syslog_path;
216 @connectMethods = qw(unix);
218 warnings::warnif 'unix passed to setlogsock, but path not available';
222 } elsif (lc $setsock eq 'pipe') {
223 for my $path ($syslog_path, &_PATH_LOG, "/dev/log") {
224 next unless defined $path and length $path and -p $path and -w _;
225 $syslog_path = $path;
229 if (not $syslog_path) {
230 warnings::warnif "pipe passed to setlogsock, but path not available";
234 @connectMethods = qw(pipe);
236 } elsif (lc $setsock eq 'native') {
237 @connectMethods = qw(native);
239 } elsif (lc $setsock eq 'eventlog') {
240 if (eval "use Win32::EventLog; 1") {
241 @connectMethods = qw(eventlog);
243 warnings::warnif "eventlog passed to setlogsock, but no Win32 API available";
248 } elsif (lc $setsock eq 'tcp') {
249 if (getservbyname('syslog', 'tcp') || getservbyname('syslogng', 'tcp')) {
250 @connectMethods = qw(tcp);
252 warnings::warnif "tcp passed to setlogsock, but tcp service unavailable";
256 } elsif (lc $setsock eq 'udp') {
257 if (getservbyname('syslog', 'udp')) {
258 @connectMethods = qw(udp);
260 warnings::warnif "udp passed to setlogsock, but udp service unavailable";
264 } elsif (lc $setsock eq 'inet') {
265 @connectMethods = ( 'tcp', 'udp' );
267 } elsif (lc $setsock eq 'console') {
268 @connectMethods = qw(console);
271 croak "Invalid argument passed to setlogsock; must be 'stream', 'pipe', ",
272 "'unix', 'native', 'eventlog', 'tcp', 'udp' or 'inet'"
279 my $priority = shift;
282 my (@words, $num, $numpri, $numfac, $sum);
284 my $fail_time = undef;
287 # if $ident is undefined, it means openlog() wasn't previously called
288 # so do it now in order to have sensible defaults
289 openlog() unless $ident;
291 local $facility = $facility; # may need to change temporarily.
293 croak "syslog: expecting argument \$priority" unless defined $priority;
294 croak "syslog: expecting argument \$format" unless defined $mask;
296 @words = split(/\W+/, $priority, 2); # Allow "level" or "level|facility".
301 $num = xlate($_); # Translate word to number.
303 croak "syslog: invalid level/facility: $_"
305 elsif ($num <= &LOG_PRIMASK) {
306 croak "syslog: too many levels given: $_" if defined $numpri;
308 return 0 unless LOG_MASK($numpri) & $maskpri;
311 croak "syslog: too many facilities given: $_" if defined $numfac;
317 croak "syslog: level must be given" unless defined $numpri;
319 if (not defined $numfac) { # Facility not specified in this call.
320 $facility = 'user' unless $facility;
321 $numfac = xlate($facility);
324 connect_log() unless $connected;
327 # escape percent signs for sprintf()
328 $error =~ s/%/%%/g if @_;
329 # replace %m with $error, if preceded by an even number of percent signs
330 $mask =~ s/(?<!%)((?:%%)*)%m/$1$error/g;
333 $mask .= "\n" unless $mask =~ /\n$/;
334 $message = @_ ? sprintf($mask, @_) : $mask;
336 # See CPAN-RT#24431. Opened on Apple Radar as bug #4944407 on 2007.01.21
337 # Supposedly resolved on Leopard.
338 chomp $message if $^O =~ /darwin/;
340 if ($current_proto eq 'native') {
343 elsif ($current_proto eq 'eventlog') {
348 $whoami .= "[$$]" if $options{pid};
350 $sum = $numpri + $numfac;
351 my $oldlocale = setlocale(LC_TIME);
352 setlocale(LC_TIME, 'C');
353 my $timestamp = strftime "%b %e %T", localtime;
354 setlocale(LC_TIME, $oldlocale);
355 $buf = "<$sum>$timestamp $whoami: $message\0";
358 # handle PERROR option
359 # "native" mechanism already handles it by itself
360 if ($options{perror} and $current_proto ne 'native') {
363 $whoami .= "[$$]" if $options{pid};
364 print STDERR "$whoami: $message\n";
367 # it's possible that we'll get an error from sending
368 # (e.g. if method is UDP and there is no UDP listener,
369 # then we'll get ECONNREFUSED on the send). So what we
370 # want to do at this point is to fallback onto a different
372 while (scalar @fallbackMethods || $syslog_send) {
373 if ($failed && (time - $fail_time) > 60) {
374 # it's been a while... maybe things have been fixed
375 @fallbackMethods = ();
377 $transmit_ok = 0; # make it look like a fresh attempt
381 if ($connected && !connection_ok()) {
382 # Something was OK, but has now broken. Remember coz we'll
383 # want to go back to what used to be OK.
384 $failed = $current_proto unless $failed;
389 connect_log() unless $connected;
390 $failed = undef if ($current_proto && $failed && $current_proto eq $failed);
393 if ($syslog_send->($buf, $numpri, $numfac)) {
397 # typically doesn't happen, since errors are rare from write().
401 # could not send, could not fallback onto a working
402 # connection method. Lose.
406 sub _syslog_send_console {
408 chop($buf); # delete the NUL from the end
409 # The console print is a method which could block
410 # so we do it in a child process and always return success
412 if (my $pid = fork) {
414 if ($options{nowait}) {
417 if (waitpid($pid, 0) >= 0) {
420 # it's possible that the caller has other
421 # plans for SIGCHLD, so let's not interfere
426 if (open(CONS, ">/dev/console")) {
427 my $ret = print CONS $buf . "\r"; # XXX: should this be \x0A ?
428 exit $ret if defined $pid;
431 exit if defined $pid;
435 sub _syslog_send_stream {
437 # XXX: this only works if the OS stream implementation makes a write
438 # look like a putmsg() with simple header. For instance it works on
439 # Solaris 8 but not Solaris 7.
440 # To be correct, it should use a STREAMS API, but perl doesn't have one.
441 return syswrite(SYSLOG, $buf, length($buf));
444 sub _syslog_send_pipe {
446 return print SYSLOG $buf;
449 sub _syslog_send_socket {
451 return syswrite(SYSLOG, $buf, length($buf));
452 #return send(SYSLOG, $buf, 0);
455 sub _syslog_send_native {
456 my ($buf, $numpri) = @_;
457 syslog_xs($numpri, $buf);
464 # private function to translate names to numeric values
468 return $name+0 if $name =~ /^\s*\d+\s*$/;
470 $name = "LOG_$name" unless $name =~ /^LOG_/;
471 $name = "Sys::Syslog::$name";
472 # Can't have just eval { &$name } || -1 because some LOG_XXX may be zero.
473 my $value = eval { no strict 'refs'; &$name };
475 return defined $value ? $value : -1;
481 # This function acts as a kind of front-end: it tries to connect to
482 # a syslog service using the selected methods, trying each one in the
486 @fallbackMethods = @connectMethods unless scalar @fallbackMethods;
488 if ($transmit_ok && $current_proto) {
489 # Retry what we were on, because it has worked in the past.
490 unshift(@fallbackMethods, $current_proto);
497 while ($proto = shift @fallbackMethods) {
499 my $fn = "connect_$proto";
500 $connected = &$fn(\@errs) if defined &$fn;
506 $current_proto = $proto;
507 my ($old) = select(SYSLOG); $| = 1; select($old);
509 @fallbackMethods = ();
510 $err_sub->(join "\n\t- ", "no connection to syslog available", @errs);
518 my $tcp = getprotobyname('tcp');
520 push @$errs, "getprotobyname failed for tcp";
524 my $syslog = getservbyname('syslog', 'tcp');
525 $syslog = getservbyname('syslogng', 'tcp') unless defined $syslog;
526 if (!defined $syslog) {
527 push @$errs, "getservbyname failed for syslog/tcp and syslogng/tcp";
533 $addr = inet_aton($host);
535 push @$errs, "can't lookup $host";
539 $addr = INADDR_LOOPBACK;
541 $addr = sockaddr_in($syslog, $addr);
543 if (!socket(SYSLOG, AF_INET, SOCK_STREAM, $tcp)) {
544 push @$errs, "tcp socket: $!";
548 setsockopt(SYSLOG, SOL_SOCKET, SO_KEEPALIVE, 1);
549 if (eval { IPPROTO_TCP() }) {
550 # These constants don't exist in 5.005. They were added in 1999
551 setsockopt(SYSLOG, IPPROTO_TCP(), TCP_NODELAY(), 1);
554 if (!connect(SYSLOG, $addr)) {
555 push @$errs, "tcp connect: $!";
559 $syslog_send = \&_syslog_send_socket;
567 my $udp = getprotobyname('udp');
569 push @$errs, "getprotobyname failed for udp";
573 my $syslog = getservbyname('syslog', 'udp');
574 if (!defined $syslog) {
575 push @$errs, "getservbyname failed for syslog/udp";
581 $addr = inet_aton($host);
583 push @$errs, "can't lookup $host";
587 $addr = INADDR_LOOPBACK;
589 $addr = sockaddr_in($syslog, $addr);
591 if (!socket(SYSLOG, AF_INET, SOCK_DGRAM, $udp)) {
592 push @$errs, "udp socket: $!";
595 if (!connect(SYSLOG, $addr)) {
596 push @$errs, "udp connect: $!";
600 # We want to check that the UDP connect worked. However the only
601 # way to do that is to send a message and see if an ICMP is returned
602 _syslog_send_socket("");
603 if (!connection_ok()) {
604 push @$errs, "udp connect: nobody listening";
608 $syslog_send = \&_syslog_send_socket;
615 # might want syslog_path to be variable based on syslog.h (if only
617 $syslog_path = '/dev/conslog' unless defined $syslog_path;
618 if (!-w $syslog_path) {
619 push @$errs, "stream $syslog_path is not writable";
622 if (!sysopen(SYSLOG, $syslog_path, 0400, O_WRONLY)) {
623 push @$errs, "stream can't open $syslog_path: $!";
626 $syslog_send = \&_syslog_send_stream;
633 $syslog_path ||= &_PATH_LOG || "/dev/log";
635 if (not -w $syslog_path) {
636 push @$errs, "$syslog_path is not writable";
640 if (not open(SYSLOG, ">$syslog_path")) {
641 push @$errs, "can't write to $syslog_path: $!";
645 $syslog_send = \&_syslog_send_pipe;
653 $syslog_path ||= _PATH_LOG() if length _PATH_LOG();
655 if (not defined $syslog_path) {
656 push @$errs, "_PATH_LOG not available in syslog.h and no user-supplied socket path";
660 if (not (-S $syslog_path or -c _)) {
661 push @$errs, "$syslog_path is not a socket";
665 my $addr = sockaddr_un($syslog_path);
667 push @$errs, "can't locate $syslog_path";
670 if (!socket(SYSLOG, AF_UNIX, SOCK_STREAM, 0)) {
671 push @$errs, "unix stream socket: $!";
675 if (!connect(SYSLOG, $addr)) {
676 if (!socket(SYSLOG, AF_UNIX, SOCK_DGRAM, 0)) {
677 push @$errs, "unix dgram socket: $!";
680 if (!connect(SYSLOG, $addr)) {
681 push @$errs, "unix dgram connect: $!";
686 $syslog_send = \&_syslog_send_socket;
695 # reconstruct the numeric equivalent of the options
696 for my $opt (keys %options) {
697 $logopt += xlate($opt) if $options{$opt}
700 eval { openlog_xs($ident, $logopt, xlate($facility)) };
706 $syslog_send = \&_syslog_send_native;
711 sub connect_eventlog {
714 $syslog_xobj = Sys::Syslog::Win32::_install();
715 $syslog_send = \&Sys::Syslog::Win32::_syslog_send;
720 sub connect_console {
722 if (!-w '/dev/console') {
723 push @$errs, "console is not writable";
726 $syslog_send = \&_syslog_send_console;
730 # To test if the connection is still good, we need to check if any
731 # errors are present on the connection. The errors will not be raised
732 # by a write. Instead, sockets are made readable and the next read
733 # would cause the error to be returned. Unfortunately the syslog
734 # 'protocol' never provides anything for us to read. But with
735 # judicious use of select(), we can see if it would be readable...
737 return 1 if defined $current_proto and (
738 $current_proto eq 'native' or $current_proto eq 'console'
739 or $current_proto eq 'eventlog'
743 vec($rin, fileno(SYSLOG), 1) = 1;
744 my $ret = select $rin, undef, $rin, 0.25;
745 return ($ret ? 0 : 1);
750 $syslog_send = undef;
752 if (defined $current_proto and $current_proto eq 'native') {
756 elsif (defined $current_proto and $current_proto eq 'eventlog') {
757 $syslog_xobj->Close();
770 Sys::Syslog - Perl interface to the UNIX syslog(3) calls
778 use Sys::Syslog; # all except setlogsock(), or:
779 use Sys::Syslog qw(:DEFAULT setlogsock); # default set, plus setlogsock()
780 use Sys::Syslog qw(:standard :macros); # standard functions, plus macros
782 openlog $ident, $logopt, $facility; # don't forget this
783 syslog $priority, $format, @args;
784 $oldmask = setlogmask $mask_priority;
790 C<Sys::Syslog> is an interface to the UNIX C<syslog(3)> program.
791 Call C<syslog()> with a string priority and a list of C<printf()> args
792 just like C<syslog(3)>.
794 You can find a kind of FAQ in L<"THE RULES OF SYS::SYSLOG">. Please read
795 it before coding, and again before asking questions.
800 C<Sys::Syslog> exports the following C<Exporter> tags:
806 C<:standard> exports the standard C<syslog(3)> functions:
808 openlog closelog setlogmask syslog
812 C<:extended> exports the Perl specific functions for C<syslog(3)>:
818 C<:macros> exports the symbols corresponding to most of your C<syslog(3)>
819 macros and the C<LOG_UPTO()> and C<LOG_MASK()> functions.
820 See L<"CONSTANTS"> for the supported constants and their meaning.
824 By default, C<Sys::Syslog> exports the symbols from the C<:standard> tag.
831 =item B<openlog($ident, $logopt, $facility)>
834 C<$ident> is prepended to every message. C<$logopt> contains zero or
835 more of the options detailed below. C<$facility> specifies the part
836 of the system to report about, for example C<LOG_USER> or C<LOG_LOCAL0>:
837 see L<"Facilities"> for a list of well-known facilities, and your
838 C<syslog(3)> documentation for the facilities available in your system.
839 Check L<"SEE ALSO"> for useful links. Facility can be given as a string
842 This function will croak if it can't connect to the syslog daemon.
844 Note that C<openlog()> now takes three arguments, just like C<openlog(3)>.
846 B<You should use C<openlog()> before calling C<syslog()>.>
854 C<cons> - This option is ignored, since the failover mechanism will drop
855 down to the console automatically if all other media fail.
859 C<ndelay> - Open the connection immediately (normally, the connection is
860 opened when the first message is logged).
864 C<nofatal> - When set to true, C<openlog()> and C<syslog()> will only
865 emit warnings instead of dying if the connection to the syslog can't
870 C<nowait> - Don't wait for child processes that may have been created
871 while logging the message. (The GNU C library does not create a child
872 process, so this option has no effect on Linux.)
876 C<perror> - Write the message to standard error output as well to the
881 C<pid> - Include PID with each message.
887 Open the syslog with options C<ndelay> and C<pid>, and with facility C<LOCAL0>:
889 openlog($name, "ndelay,pid", "local0");
891 Same thing, but this time using the macro corresponding to C<LOCAL0>:
893 openlog($name, "ndelay,pid", LOG_LOCAL0);
896 =item B<syslog($priority, $message)>
898 =item B<syslog($priority, $format, @args)>
900 If C<$priority> permits, logs C<$message> or C<sprintf($format, @args)>
901 with the addition that C<%m> in $message or C<$format> is replaced with
902 C<"$!"> (the latest error message).
904 C<$priority> can specify a level, or a level and a facility. Levels and
905 facilities can be given as strings or as macros. When using the C<eventlog>
906 mechanism, priorities C<DEBUG> and C<INFO> are mapped to event type
907 C<informational>, C<NOTICE> and C<WARNIN> to C<warning> and C<ERR> to
908 C<EMERG> to C<error>.
910 If you didn't use C<openlog()> before using C<syslog()>, C<syslog()> will
911 try to guess the C<$ident> by extracting the shortest prefix of
912 C<$format> that ends in a C<":">.
916 syslog("info", $message); # informational level
917 syslog(LOG_INFO, $message); # informational level
919 syslog("info|local0", $message); # information level, Local0 facility
920 syslog(LOG_INFO|LOG_LOCAL0, $message); # information level, Local0 facility
926 C<Sys::Syslog> version v0.07 and older passed the C<$message> as the
927 formatting string to C<sprintf()> even when no formatting arguments
928 were provided. If the code calling C<syslog()> might execute with
929 older versions of this module, make sure to call the function as
930 C<syslog($priority, "%s", $message)> instead of C<syslog($priority,
931 $message)>. This protects against hostile formatting sequences that
932 might show up if $message contains tainted data.
937 =item B<setlogmask($mask_priority)>
939 Sets the log mask for the current process to C<$mask_priority> and
940 returns the old mask. If the mask argument is 0, the current log mask
941 is not modified. See L<"Levels"> for the list of available levels.
942 You can use the C<LOG_UPTO()> function to allow all levels up to a
943 given priority (but it only accept the numeric macros as arguments).
949 setlogmask( LOG_MASK(LOG_ERR) );
951 Log everything except informational messages:
953 setlogmask( ~(LOG_MASK(LOG_INFO)) );
955 Log critical messages, errors and warnings:
957 setlogmask( LOG_MASK(LOG_CRIT) | LOG_MASK(LOG_ERR) | LOG_MASK(LOG_WARNING) );
959 Log all messages up to debug:
961 setlogmask( LOG_UPTO(LOG_DEBUG) );
964 =item B<setlogsock($sock_type)>
966 =item B<setlogsock($sock_type, $stream_location)> (added in Perl 5.004_02)
968 Sets the socket type to be used for the next call to
969 C<openlog()> or C<syslog()> and returns true on success,
970 C<undef> on failure. The available mechanisms are:
976 C<"native"> - use the native C functions from your C<syslog(3)> library
977 (added in C<Sys::Syslog> 0.15).
981 C<"eventlog"> - send messages to the Win32 events logger (Win32 only;
982 added in C<Sys::Syslog> 0.19).
986 C<"tcp"> - connect to a TCP socket, on the C<syslog/tcp> or C<syslogng/tcp>
991 C<"udp"> - connect to a UDP socket, on the C<syslog/udp> service.
995 C<"inet"> - connect to an INET socket, either TCP or UDP, tried in that order.
999 C<"unix"> - connect to a UNIX domain socket (in some systems a character
1000 special device). The name of that socket is the second parameter or, if
1001 you omit the second parameter, the value returned by the C<_PATH_LOG> macro
1002 (if your system defines it), or F</dev/log> or F</dev/conslog>, whatever is
1007 C<"stream"> - connect to the stream indicated by the pathname provided as
1008 the optional second parameter, or, if omitted, to F</dev/conslog>.
1009 For example Solaris and IRIX system may prefer C<"stream"> instead of C<"unix">.
1013 C<"pipe"> - connect to the named pipe indicated by the pathname provided as
1014 the optional second parameter, or, if omitted, to the value returned by
1015 the C<_PATH_LOG> macro (if your system defines it), or F</dev/log>
1016 (added in C<Sys::Syslog> 0.21).
1020 C<"console"> - send messages directly to the console, as for the C<"cons">
1021 option of C<openlog()>.
1025 A reference to an array can also be passed as the first parameter.
1026 When this calling method is used, the array should contain a list of
1027 mechanisms which are attempted in order.
1029 The default is to try C<native>, C<tcp>, C<udp>, C<unix>, C<stream>, C<console>.
1030 Under systems with the Win32 API, C<eventlog> will be added as the first
1031 mechanism to try if C<Win32::EventLog> is available.
1033 Giving an invalid value for C<$sock_type> will C<croak>.
1037 Select the UDP socket mechanism:
1041 Select the native, UDP socket then UNIX domain socket mechanisms:
1043 setlogsock(["native", "udp", "unix"]);
1049 Now that the "native" mechanism is supported by C<Sys::Syslog> and selected
1050 by default, the use of the C<setlogsock()> function is discouraged because
1051 other mechanisms are less portable across operating systems. Authors of
1052 modules and programs that use this function, especially its cargo-cult form
1053 C<setlogsock("unix")>, are advised to remove any occurence of it unless they
1054 specifically want to use a given mechanism (like TCP or UDP to connect to
1061 Closes the log file and returns true on success.
1066 =head1 THE RULES OF SYS::SYSLOG
1068 I<The First Rule of Sys::Syslog is:>
1069 You do not call C<setlogsock>.
1071 I<The Second Rule of Sys::Syslog is:>
1072 You B<do not> call C<setlogsock>.
1074 I<The Third Rule of Sys::Syslog is:>
1075 The program crashes, C<die>s, calls C<closelog>, the log is over.
1077 I<The Fourth Rule of Sys::Syslog is:>
1078 One facility, one priority.
1080 I<The Fifth Rule of Sys::Syslog is:>
1083 I<The Sixth Rule of Sys::Syslog is:>
1084 No C<syslog> before C<openlog>.
1086 I<The Seventh Rule of Sys::Syslog is:>
1087 Logs will go on as long as they have to.
1089 I<The Eighth, and Final Rule of Sys::Syslog is:>
1090 If this is your first use of Sys::Syslog, you must read the doc.
1097 openlog($program, 'cons,pid', 'user');
1098 syslog('info', '%s', 'this is another test');
1099 syslog('mail|warning', 'this is a better test: %d', time);
1102 syslog('debug', 'this is the last test');
1106 openlog("$program $$", 'ndelay', 'user');
1107 syslog('notice', 'fooprogram: this is really done');
1109 Example of use of C<%m>:
1112 syslog('info', 'problem was %m'); # %m == $! in syslog(3)
1114 Log to UDP port on C<$remotehost> instead of logging locally:
1117 $Sys::Syslog::host = $remotehost;
1118 openlog($program, 'ndelay', 'user');
1119 syslog('info', 'something happened over here');
1130 C<LOG_AUDIT> - audit daemon (IRIX); falls back to C<LOG_AUTH>
1134 C<LOG_AUTH> - security/authorization messages
1138 C<LOG_AUTHPRIV> - security/authorization messages (private)
1142 C<LOG_CONSOLE> - C</dev/console> output (FreeBSD); falls back to C<LOG_USER>
1146 C<LOG_CRON> - clock daemons (B<cron> and B<at>)
1150 C<LOG_DAEMON> - system daemons without separate facility value
1154 C<LOG_FTP> - FTP daemon
1158 C<LOG_KERN> - kernel messages
1162 C<LOG_INSTALL> - installer subsystem (Mac OS X); falls back to C<LOG_USER>
1166 C<LOG_LAUNCHD> - launchd - general bootstrap daemon (Mac OS X);
1167 falls back to C<LOG_DAEMON>
1171 C<LOG_LFMT> - logalert facility; falls back to C<LOG_USER>
1175 C<LOG_LOCAL0> through C<LOG_LOCAL7> - reserved for local use
1179 C<LOG_LPR> - line printer subsystem
1183 C<LOG_MAIL> - mail subsystem
1187 C<LOG_NETINFO> - NetInfo subsystem (Mac OS X); falls back to C<LOG_DAEMON>
1191 C<LOG_NEWS> - USENET news subsystem
1195 C<LOG_NTP> - NTP subsystem (FreeBSD, NetBSD); falls back to C<LOG_DAEMON>
1199 C<LOG_RAS> - Remote Access Service (VPN / PPP) (Mac OS X);
1200 falls back to C<LOG_AUTH>
1204 C<LOG_REMOTEAUTH> - remote authentication/authorization (Mac OS X);
1205 falls back to C<LOG_AUTH>
1209 C<LOG_SECURITY> - security subsystems (firewalling, etc.) (FreeBSD);
1210 falls back to C<LOG_AUTH>
1214 C<LOG_SYSLOG> - messages generated internally by B<syslogd>
1218 C<LOG_USER> (default) - generic user-level messages
1222 C<LOG_UUCP> - UUCP subsystem
1233 C<LOG_EMERG> - system is unusable
1237 C<LOG_ALERT> - action must be taken immediately
1241 C<LOG_CRIT> - critical conditions
1245 C<LOG_ERR> - error conditions
1249 C<LOG_WARNING> - warning conditions
1253 C<LOG_NOTICE> - normal, but significant, condition
1257 C<LOG_INFO> - informational message
1261 C<LOG_DEBUG> - debug-level message
1270 =item C<Invalid argument passed to setlogsock>
1272 B<(F)> You gave C<setlogsock()> an invalid value for C<$sock_type>.
1274 =item C<eventlog passed to setlogsock, but no Win32 API available>
1276 B<(W)> You asked C<setlogsock()> to use the Win32 event logger but the
1277 operating system running the program isn't Win32 or does not provides Win32
1278 compatible facilities.
1280 =item C<no connection to syslog available>
1282 B<(F)> C<syslog()> failed to connect to the specified socket.
1284 =item C<stream passed to setlogsock, but %s is not writable>
1286 B<(W)> You asked C<setlogsock()> to use a stream socket, but the given
1287 path is not writable.
1289 =item C<stream passed to setlogsock, but could not find any device>
1291 B<(W)> You asked C<setlogsock()> to use a stream socket, but didn't
1292 provide a path, and C<Sys::Syslog> was unable to find an appropriate one.
1294 =item C<tcp passed to setlogsock, but tcp service unavailable>
1296 B<(W)> You asked C<setlogsock()> to use a TCP socket, but the service
1297 is not available on the system.
1299 =item C<syslog: expecting argument %s>
1301 B<(F)> You forgot to give C<syslog()> the indicated argument.
1303 =item C<syslog: invalid level/facility: %s>
1305 B<(F)> You specified an invalid level or facility.
1307 =item C<syslog: too many levels given: %s>
1309 B<(F)> You specified too many levels.
1311 =item C<syslog: too many facilities given: %s>
1313 B<(F)> You specified too many facilities.
1315 =item C<syslog: level must be given>
1317 B<(F)> You forgot to specify a level.
1319 =item C<udp passed to setlogsock, but udp service unavailable>
1321 B<(W)> You asked C<setlogsock()> to use a UDP socket, but the service
1322 is not available on the system.
1324 =item C<unix passed to setlogsock, but path not available>
1326 B<(W)> You asked C<setlogsock()> to use a UNIX socket, but C<Sys::Syslog>
1327 was unable to find an appropriate an appropriate device.
1338 SUSv3 issue 6, IEEE Std 1003.1, 2004 edition,
1339 L<http://www.opengroup.org/onlinepubs/000095399/basedefs/syslog.h.html>
1341 GNU C Library documentation on syslog,
1342 L<http://www.gnu.org/software/libc/manual/html_node/Syslog.html>
1344 Solaris 10 documentation on syslog,
1345 L<http://docs.sun.com/app/docs/doc/816-5168/6mbb3hruo?a=view>
1347 IRIX 6.4 documentation on syslog,
1348 L<http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=0640&db=man&fname=3c+syslog>
1350 AIX 5L 5.3 documentation on syslog,
1351 L<http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.basetechref/doc/basetrf2/syslog.htm>
1353 HP-UX 11i documentation on syslog,
1354 L<http://docs.hp.com/en/B9106-90010/syslog.3C.html>
1356 Tru64 5.1 documentation on syslog,
1357 L<http://h30097.www3.hp.com/docs/base_doc/DOCUMENTATION/V51_HTML/MAN/MAN3/0193____.HTM>
1360 L<http://stratadoc.stratus.com/vos/15.1.1/r502-01/wwhelp/wwhimpl/js/html/wwhelp.htm?context=r502-01&file=ch5r502-01bi.html>
1364 I<RFC 3164 - The BSD syslog Protocol>, L<http://www.faqs.org/rfcs/rfc3164.html>
1365 -- Please note that this is an informational RFC, and therefore does not
1366 specify a standard of any kind.
1368 I<RFC 3195 - Reliable Delivery for syslog>, L<http://www.faqs.org/rfcs/rfc3195.html>
1372 I<Syslogging with Perl>, L<http://lexington.pm.org/meetings/022001.html>
1377 L<http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wes/wes/windows_event_log.asp>
1380 =head1 AUTHORS & ACKNOWLEDGEMENTS
1382 Tom Christiansen E<lt>F<tchrist (at) perl.com>E<gt> and Larry Wall
1383 E<lt>F<larry (at) wall.org>E<gt>.
1385 UNIX domain sockets added by Sean Robinson
1386 E<lt>F<robinson_s (at) sc.maricopa.edu>E<gt> with support from Tim Bunce
1387 E<lt>F<Tim.Bunce (at) ig.co.uk>E<gt> and the C<perl5-porters> mailing list.
1389 Dependency on F<syslog.ph> replaced with XS code by Tom Hughes
1390 E<lt>F<tom (at) compton.nu>E<gt>.
1392 Code for C<constant()>s regenerated by Nicholas Clark E<lt>F<nick (at) ccl4.org>E<gt>.
1394 Failover to different communication modes by Nick Williams
1395 E<lt>F<Nick.Williams (at) morganstanley.com>E<gt>.
1397 Extracted from core distribution for publishing on the CPAN by
1398 SE<eacute>bastien Aperghis-Tramoni E<lt>sebastien (at) aperghis.netE<gt>.
1400 XS code for using native C functions borrowed from C<L<Unix::Syslog>>,
1401 written by Marcus Harnisch E<lt>F<marcus.harnisch (at) gmx.net>E<gt>.
1403 Yves Orton suggested and helped for making C<Sys::Syslog> use the native
1404 event logger under Win32 systems.
1406 Jerry D. Hedden and Reini Urban provided greatly appreciated help to
1407 debug and polish C<Sys::Syslog> under Cygwin.
1412 Please report any bugs or feature requests to
1413 C<bug-sys-syslog (at) rt.cpan.org>, or through the web interface at
1414 L<http://rt.cpan.org/Public/Dist/Display.html?Name=Sys-Syslog>.
1415 I will be notified, and then you'll automatically be notified of progress on
1416 your bug as I make changes.
1421 You can find documentation for this module with the perldoc command.
1425 You can also look for information at:
1429 =item * AnnoCPAN: Annotated CPAN documentation
1431 L<http://annocpan.org/dist/Sys-Syslog>
1433 =item * CPAN Ratings
1435 L<http://cpanratings.perl.org/d/Sys-Syslog>
1437 =item * RT: CPAN's request tracker
1439 L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Sys-Syslog>
1443 L<http://search.cpan.org/dist/Sys-Syslog/>
1445 =item * Kobes' CPAN Search
1447 L<http://cpan.uwinnipeg.ca/dist/Sys-Syslog>
1449 =item * Perl Documentation
1451 L<http://perldoc.perl.org/Sys/Syslog.html>
1458 Copyright (C) 1990-2007 by Larry Wall and others.
1463 This program is free software; you can redistribute it and/or modify it
1464 under the same terms as Perl itself.
1470 Notes for the future maintainer (even if it's still me..)
1471 - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1473 Using Google Code Search, I search who on Earth was relying on $host being
1474 public. It found 5 hits:
1476 * First was inside Indigo Star Perl2exe documentation. Just an old version
1480 * One real hit was inside DalWeathDB, a weather related program. It simply
1483 $Sys::Syslog::host = '127.0.0.1';
1485 - L<http://www.gallistel.net/nparker/weather/code/>
1488 * Two hits were in TPC, a fax server thingy. It does a
1490 $Sys::Syslog::host = $TPC::LOGHOST;
1492 but also has this strange piece of code:
1494 # work around perl5.003 bug
1495 sub Sys::Syslog::hostname {}
1497 I don't know what bug the author referred to.
1499 - L<http://www.tpc.int/>
1500 - L<ftp://ftp.tpc.int/tpc/server/UNIX/>
1501 - L<ftp://ftp-usa.tpc.int/pub/tpc/server/UNIX/>
1504 * Last hit was in Filefix, which seems to be a FIDOnet mail program (!).
1505 This one does not use $host, but has the following piece of code:
1507 sub Sys::Syslog::hostname
1513 I guess this was a more elaborate form of the previous bit, maybe because
1514 of a bug in Sys::Syslog back then?
1516 - L<ftp://ftp.kiae.su/pub/unix/fido/>
1521 II12021: SYSLOGD HOWTO TCPIPINFO (z/OS, OS/390, MVS)
1522 - L<http://www-1.ibm.com/support/docview.wss?uid=isg1II12021>
1524 Getting the most out of the Event Viewer
1525 - L<http://www.codeproject.com/dotnet/evtvwr.asp?print=true>
1527 Log events to the Windows NT Event Log with JNI
1528 - L<http://www.javaworld.com/javaworld/jw-09-2001/jw-0928-ntmessages.html>