package Sys::Syslog;require 5.000;require Exporter;require DynaLoader;use Carp;@ISA = qw(Exporter DynaLoader);@EXPORT = qw(openlog closelog setlogmask syslog);@EXPORT_OK = qw(setlogsock);$VERSION = '0.01';use Socket;use Sys::Hostname;# adapted from syslog.pl## Tom Christiansen <tchrist@convex.com># modified to use sockets by Larry Wall <lwall@jpl-devvax.jpl.nasa.gov># NOTE: openlog now takes three arguments, just like openlog(3)# Modified to add UNIX domain sockets by Sean Robinson <robinson_s@sc.maricopa.edu>#  with support from Tim Bunce <Tim.Bunce@ig.co.uk> and the perl5-porters mailing list# Modified to use an XS backend instead of syslog.ph by Tom Hughes <tom@compton.nu># Todo: enable connect to try all three types before failing (auto setlogsock)?=head1 NAMESys::Syslog, openlog, closelog, setlogmask, syslog - Perl interface to the UNIX syslog(3) calls=head1 SYNOPSIS    use Sys::Syslog;                          # all except setlogsock, or:    use Sys::Syslog qw(:DEFAULT setlogsock);  # default set, plus setlogsock    setlogsock $sock_type;    openlog $ident, $logopt, $facility;    syslog $priority, $format, @args;    $oldmask = setlogmask $mask_priority;    closelog;=head1 DESCRIPTIONSys::Syslog is an interface to the UNIX C<syslog(3)> program.Call C<syslog()> with a string priority and a list of C<printf()> argsjust like C<syslog(3)>.Syslog provides the functions:=over=item openlog $ident, $logopt, $facilityI<$ident> is prepended to every message.I<$logopt> contains zero or more of the words I<pid>, I<ndelay>, I<cons>, I<nowait>.I<$facility> specifies the part of the system=item syslog $priority, $format, @argsIf I<$priority> permits, logs I<($format, @args)>printed as by C<printf(3V)>, with the addition that I<%m>is replaced with C<"$!"> (the latest error message).=item setlogmask $mask_prioritySets log mask I<$mask_priority> and returns the old mask.=item setlogsock $sock_type (added in 5.004_02)Sets the socket type to be used for the next call toC<openlog()> or C<syslog()> and returns TRUE on success,undef on failure.A value of 'unix' will connect to the UNIX domain socket returned by theC<_PATH_LOG> macro (if you system defines it) in F<syslog.h>.  A value of'inet' will connect to an INET socket returned by getservbyname().  IfC<_PATH_LOG> is unavailable or if getservbyname() fails, returns undef.  Anyother value croaks.The default is for the INET socket to be used.=item closelogCloses the log file.=backNote that C<openlog> now takes three arguments, just like C<openlog(3)>.=head1 EXAMPLES    openlog($program, 'cons,pid', 'user');    syslog('info', '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)=head1 SEE ALSOL<syslog(3)>=head1 AUTHORTom Christiansen E<lt>F<tchrist@perl.com>E<gt> and Larry WallE<lt>F<larry@wall.org>E<gt>.UNIX domain sockets added by Sean RobinsonE<lt>F<robinson_s@sc.maricopa.edu>E<gt> with support from Tim BunceE<lt>F<Tim.Bunce@ig.co.uk>E<gt> and the perl5-porters mailing list.Dependency on F<syslog.ph> replaced with XS code by Tom HughesE<lt>F<tom@compton.nu>E<gt>.=cutsub AUTOLOAD {    # This AUTOLOAD is used to 'autoload' constants from the constant()    # XS function.    my $constname;    our $AUTOLOAD;    ($constname = $AUTOLOAD) =~ s/.*:://;    croak "& not defined" if $constname eq 'constant';    my $val = constant($constname);    if ($! != 0) {	croak "Your vendor has not defined Sys::Syslog macro $constname";    }    *$AUTOLOAD = sub { $val };    goto &$AUTOLOAD;}bootstrap Sys::Syslog $VERSION;$maskpri = &LOG_UPTO(&LOG_DEBUG);sub openlog {    ($ident, $logopt, $facility) = @_;  # package vars    $lo_pid = $logopt =~ /\bpid\b/;    $lo_ndelay = $logopt =~ /\bndelay\b/;    $lo_cons = $logopt =~ /\bcons\b/;    $lo_nowait = $logopt =~ /\bnowait\b/;    return 1 unless $lo_ndelay;    &connect;} sub closelog {    $facility = $ident = '';    &disconnect;} sub setlogmask {    local($oldmask) = $maskpri;    $maskpri = shift;    $oldmask;} sub setlogsock {    local($setsock) = shift;    &disconnect if $connected;    if (lc($setsock) eq 'unix') {        if (length _PATH_LOG()) {            $sock_type = 1;        } else {            return undef;        }    } elsif (lc($setsock) eq 'inet') {        if (getservbyname('syslog','udp')) {            undef($sock_type);        } else {            return undef;        }    } else {        croak "Invalid argument passed to setlogsock; must be 'unix' or 'inet'";    }    return 1;}sub syslog {    local($priority) = shift;    local($mask) = shift;    local($message, $whoami);    local(@words, $num, $numpri, $numfac, $sum);    local($facility) = $facility;	# may need to change temporarily.    croak "syslog: expected both priority and mask" unless $mask && $priority;    @words = split(/\W+/, $priority, 2);# Allow "level" or "level|facility".    undef $numpri;    undef $numfac;    foreach (@words) {	$num = &xlate($_);		# Translate word to number.	if (/^kern$/ || $num < 0) {	    croak "syslog: invalid level/facility: $_";	}	elsif ($num <= &LOG_PRIMASK) {	    croak "syslog: too many levels given: $_" if defined($numpri);	    $numpri = $num;	    return 0 unless &LOG_MASK($numpri) & $maskpri;	}	else {	    croak "syslog: too many facilities given: $_" if defined($numfac);	    $facility = $_;	    $numfac = $num;	}    }    croak "syslog: level must be given" unless defined($numpri);    if (!defined($numfac)) {	# Facility not specified in this call.	$facility = 'user' unless $facility;	$numfac = &xlate($facility);    }    &connect unless $connected;    $whoami = $ident;    if (!$whoami && $mask =~ /^(\S.*?):\s?(.*)/) {	$whoami = $1;	$mask = $2;    }     unless ($whoami) {	($whoami = getlogin) ||	    ($whoami = getpwuid($<)) ||		($whoami = 'syslog');    }    $whoami .= "[$$]" if $lo_pid;    $mask =~ s/%m/$!/g;    $mask .= "\n" unless $mask =~ /\n$/;    $message = sprintf ($mask, @_);    $sum = $numpri + $numfac;    unless (send(SYSLOG,"<$sum>$whoami: $message\0",0)) {	if ($lo_cons) {	    if ($pid = fork) {		unless ($lo_nowait) {		    $died = waitpid($pid, 0);		}	    }	    else {		if (open(CONS,">/dev/console")) {		    print CONS "<$facility.$priority>$whoami: $message\r";		    close CONS;		}		exit if defined $pid;		# if fork failed, we're parent	    }	}    }}sub xlate {    local($name) = @_;    $name = uc $name;    $name = "LOG_$name" unless $name =~ /^LOG_/;    $name = "Sys::Syslog::$name";    eval { &$name } || -1;}sub connect {    unless ($host) {	require Sys::Hostname;	my($host_uniq) = Sys::Hostname::hostname();	($host) = $host_uniq =~ /([A-Za-z0-9_.-]+)/; # allow FQDN (inc _)    }    unless ( $sock_type ) {        my $udp = getprotobyname('udp')                 || croak "getprotobyname failed for udp";        my $syslog = getservbyname('syslog','udp')      || croak "getservbyname failed";        my $this = sockaddr_in($syslog, INADDR_ANY);        my $that = sockaddr_in($syslog, inet_aton($host) || croak "Can't lookup $host");        socket(SYSLOG,AF_INET,SOCK_DGRAM,$udp)           || croak "socket: $!";        connect(SYSLOG,$that)                            || croak "connect: $!";    } else {        my $syslog = _PATH_LOG();	length($syslog)                                  || croak "_PATH_LOG unavailable in syslog.h";        my $that = sockaddr_un($syslog)                  || croak "Can't locate $syslog";        socket(SYSLOG,AF_UNIX,SOCK_STREAM,0)             || croak "socket: $!";        if (!connect(SYSLOG,$that)) {            socket(SYSLOG,AF_UNIX,SOCK_DGRAM,0)          || croak "socket: $!";            connect(SYSLOG,$that) || croak "connect: $! (SOCK_DGRAM after trying SOCK_STREAM)";        }    }    local($old) = select(SYSLOG); $| = 1; select($old);    $connected = 1;}sub disconnect {    close SYSLOG;    $connected = 0;}1;