package Sys::Syslog; require 5.000; require Exporter; use Carp; @ISA = qw(Exporter); @EXPORT = qw(openlog closelog setlogmask syslog); @EXPORT_OK = qw(setlogsock); use Socket; use Sys::Hostname; # adapted from syslog.pl # # Tom Christiansen # modified to use sockets by Larry Wall # NOTE: openlog now takes three arguments, just like openlog(3) # Modified to add UNIX domain sockets by Sean Robinson # with support from Tim Bunce and the perl5-porters mailing list # Todo: enable connect to try all three types before failing (auto setlogsock)? =head1 NAME Sys::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 DESCRIPTION Sys::Syslog is an interface to the UNIX C program. Call C with a string priority and a list of C args just like C. Syslog provides the functions: =over =item openlog $ident, $logopt, $facility I<$ident> is prepended to every message. I<$logopt> contains zero or more of the words I, I, I, I. I<$facility> specifies the part of the system =item syslog $priority, $format, @args If I<$priority> permits, logs I<($format, @args)> printed as by C, with the addition that I<%m> is replaced with C<"$!"> (the latest error message). =item setlogmask $mask_priority Sets log mask I<$mask_priority> and returns the old mask. =item setlogsock $sock_type (added in 5.004_02) Sets the socket type to be used for the next call to C or C and returns TRUE on success, undef on failure. A value of 'unix' will connect to the UNIX domain socket returned by C<_PATH_LOG> in F. A value of 'inet' will connect to an INET socket returned by getservbyname(). Any other value croaks. The default is for the INET socket to be used. =item closelog Closes the log file. =back Note that C now takes three arguments, just like C. =head1 EXAMPLES openlog($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 DEPENDENCIES B needs F, which can be created with C. =head1 SEE ALSO L =head1 AUTHOR Tom Christiansen EFE and Larry Wall EFE. UNIX domain sockets added by Sean Robinson EFE with support from Tim Bunce and the perl5-porters mailing list. =cut require 'syslog.ph'; $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/; &connect if $lo_ndelay; } 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 (defined &_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 { open(CONS,">/dev/console"); print CONS "<$facility.$priority>$whoami: $message\r"; exit if defined $pid; # if fork failed, we're parent close CONS; } } } } sub xlate { local($name) = @_; $name = uc $name; $name = "LOG_$name" unless $name =~ /^LOG_/; $name = "Sys::Syslog::$name"; defined &$name ? &$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'); my $syslog = getservbyname('syslog','udp'); 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 || croak "_PATH_LOG not found in syslog.ph"; 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;