lib/perl5/5.6.1/msys/Sys/Syslog.pm

   1 package Sys::Syslog;
   2 require 5.000;
   3 require Exporter;
   4 require DynaLoader;
   5 use Carp;
   6
   7 @ISA = qw(Exporter DynaLoader);
   8 @EXPORT = qw(openlog closelog setlogmask syslog);
   9 @EXPORT_OK = qw(setlogsock);
  10 $VERSION = '0.01';
  11
  12 use Socket;
  13 use Sys::Hostname;
  14
  15 # adapted from syslog.pl
  16 #
  17 # Tom Christiansen <tchrist@convex.com>
  18 # modified to use sockets by Larry Wall <lwall@jpl-devvax.jpl.nasa.gov>
  19 # NOTE: openlog now takes three arguments, just like openlog(3)
  20 # Modified to add UNIX domain sockets by Sean Robinson <robinson_s@sc.maricopa.edu>
  21 #  with support from Tim Bunce <Tim.Bunce@ig.co.uk> and the perl5-porters mailing list
  22 # Modified to use an XS backend instead of syslog.ph by Tom Hughes <tom@compton.nu>
  23
  24 # Todo: enable connect to try all three types before failing (auto setlogsock)?
  25
  26 =head1 NAME
  27
  28 Sys::Syslog, openlog, closelog, setlogmask, syslog - Perl interface to the UNIX syslog(3) calls
  29
  30 =head1 SYNOPSIS
  31
  32     use Sys::Syslog;                          # all except setlogsock, or:
  33     use Sys::Syslog qw(:DEFAULT setlogsock);  # default set, plus setlogsock
  34
  35     setlogsock $sock_type;
  36     openlog $ident, $logopt, $facility;
  37     syslog $priority, $format, @args;
  38     $oldmask = setlogmask $mask_priority;
  39     closelog;
  40
  41 =head1 DESCRIPTION
  42
  43 Sys::Syslog is an interface to the UNIX C<syslog(3)> program.
  44 Call C<syslog()> with a string priority and a list of C<printf()> args
  45 just like C<syslog(3)>.
  46
  47 Syslog provides the functions:
  48
  49 =over
  50
  51 =item openlog $ident, $logopt, $facility
  52
  53 I<$ident> is prepended to every message.
  54 I<$logopt> contains zero or more of the words I<pid>, I<ndelay>, I<cons>, I<nowait>.
  55 I<$facility> specifies the part of the system
  56
  57 =item syslog $priority, $format, @args
  58
  59 If I<$priority> permits, logs I<($format, @args)>
  60 printed as by C<printf(3V)>, with the addition that I<%m>
  61 is replaced with C<"$!"> (the latest error message).
  62
  63 =item setlogmask $mask_priority
  64
  65 Sets log mask I<$mask_priority> and returns the old mask.
  66
  67 =item setlogsock $sock_type (added in 5.004_02)
  68
  69 Sets the socket type to be used for the next call to
  70 C<openlog()> or C<syslog()> and returns TRUE on success,
  71 undef on failure.
  72
  73 A value of 'unix' will connect to the UNIX domain socket returned by the
  74 C<_PATH_LOG> macro (if you system defines it) in F<syslog.h>.  A value of
  75 'inet' will connect to an INET socket returned by getservbyname().  If
  76 C<_PATH_LOG> is unavailable or if getservbyname() fails, returns undef.  Any
  77 other value croaks.
  78
  79 The default is for the INET socket to be used.
  80
  81 =item closelog
  82
  83 Closes the log file.
  84
  85 =back
  86
  87 Note that C<openlog> now takes three arguments, just like C<openlog(3)>.
  88
  89 =head1 EXAMPLES
  90
  91     openlog($program, 'cons,pid', 'user');
  92     syslog('info', 'this is another test');
  93     syslog('mail|warning', 'this is a better test: %d', time);
  94     closelog();
  95
  96     syslog('debug', 'this is the last test');
  97
  98     setlogsock('unix');
  99     openlog("$program $$", 'ndelay', 'user');
 100     syslog('notice', 'fooprogram: this is really done');
 101
 102     setlogsock('inet');
 103     $! = 55;
 104     syslog('info', 'problem was %m'); # %m == $! in syslog(3)
 105
 106 =head1 SEE ALSO
 107
 108 L<syslog(3)>
 109
 110 =head1 AUTHOR
 111
 112 Tom Christiansen E<lt>F<tchrist@perl.com>E<gt> and Larry Wall
 113 E<lt>F<larry@wall.org>E<gt>.
 114
 115 UNIX domain sockets added by Sean Robinson
 116 E<lt>F<robinson_s@sc.maricopa.edu>E<gt> with support from Tim Bunce
 117 E<lt>F<Tim.Bunce@ig.co.uk>E<gt> and the perl5-porters mailing list.
 118
 119 Dependency on F<syslog.ph> replaced with XS code by Tom Hughes
 120 E<lt>F<tom@compton.nu>E<gt>.
 121
 122 =cut
 123
 124 sub AUTOLOAD {
 125     # This AUTOLOAD is used to 'autoload' constants from the constant()
 126     # XS function.
 127
 128     my $constname;
 129     our $AUTOLOAD;
 130     ($constname = $AUTOLOAD) =~ s/.*:://;
 131     croak "& not defined" if $constname eq 'constant';
 132     my $val = constant($constname);
 133     if ($! != 0) {
 134         croak "Your vendor has not defined Sys::Syslog macro $constname";
 135     }
 136     *$AUTOLOAD = sub { $val };
 137     goto &$AUTOLOAD;
 138 }
 139
 140 bootstrap Sys::Syslog $VERSION;
 141
 142 $maskpri = &LOG_UPTO(&LOG_DEBUG);
 143
 144 sub openlog {
 145     ($ident, $logopt, $facility) = @_;  # package vars
 146     $lo_pid = $logopt =~ /\bpid\b/;
 147     $lo_ndelay = $logopt =~ /\bndelay\b/;
 148     $lo_cons = $logopt =~ /\bcons\b/;
 149     $lo_nowait = $logopt =~ /\bnowait\b/;
 150     return 1 unless $lo_ndelay;
 151     &connect;
 152 }
 153
 154 sub closelog {
 155     $facility = $ident = '';
 156     &disconnect;
 157 }
 158
 159 sub setlogmask {
 160     local($oldmask) = $maskpri;
 161     $maskpri = shift;
 162     $oldmask;
 163 }
 164
 165 sub setlogsock {
 166     local($setsock) = shift;
 167     &disconnect if $connected;
 168     if (lc($setsock) eq 'unix') {
 169         if (length _PATH_LOG()) {
 170             $sock_type = 1;
 171         } else {
 172             return undef;
 173         }
 174     } elsif (lc($setsock) eq 'inet') {
 175         if (getservbyname('syslog','udp')) {
 176             undef($sock_type);
 177         } else {
 178             return undef;
 179         }
 180     } else {
 181         croak "Invalid argument passed to setlogsock; must be 'unix' or 'inet'";
 182     }
 183     return 1;
 184 }
 185
 186 sub syslog {
 187     local($priority) = shift;
 188     local($mask) = shift;
 189     local($message, $whoami);
 190     local(@words, $num, $numpri, $numfac, $sum);
 191     local($facility) = $facility;       # may need to change temporarily.
 192
 193     croak "syslog: expected both priority and mask" unless $mask && $priority;
 194
 195     @words = split(/\W+/, $priority, 2);# Allow "level" or "level|facility".
 196     undef $numpri;
 197     undef $numfac;
 198     foreach (@words) {
 199         $num = &xlate($_);              # Translate word to number.
 200         if (/^kern$/ || $num < 0) {
 201             croak "syslog: invalid level/facility: $_";
 202         }
 203         elsif ($num <= &LOG_PRIMASK) {
 204             croak "syslog: too many levels given: $_" if defined($numpri);
 205             $numpri = $num;
 206             return 0 unless &LOG_MASK($numpri) & $maskpri;
 207         }
 208         else {
 209             croak "syslog: too many facilities given: $_" if defined($numfac);
 210             $facility = $_;
 211             $numfac = $num;
 212         }
 213     }
 214
 215     croak "syslog: level must be given" unless defined($numpri);
 216
 217     if (!defined($numfac)) {    # Facility not specified in this call.
 218         $facility = 'user' unless $facility;
 219         $numfac = &xlate($facility);
 220     }
 221
 222     &connect unless $connected;
 223
 224     $whoami = $ident;
 225
 226     if (!$whoami && $mask =~ /^(\S.*?):\s?(.*)/) {
 227         $whoami = $1;
 228         $mask = $2;
 229     }
 230
 231     unless ($whoami) {
 232         ($whoami = getlogin) ||
 233             ($whoami = getpwuid($<)) ||
 234                 ($whoami = 'syslog');
 235     }
 236
 237     $whoami .= "[$$]" if $lo_pid;
 238
 239     $mask =~ s/%m/$!/g;
 240     $mask .= "\n" unless $mask =~ /\n$/;
 241     $message = sprintf ($mask, @_);
 242
 243     $sum = $numpri + $numfac;
 244     unless (send(SYSLOG,"<$sum>$whoami: $message\0",0)) {
 245         if ($lo_cons) {
 246             if ($pid = fork) {
 247                 unless ($lo_nowait) {
 248                     $died = waitpid($pid, 0);
 249                 }
 250             }
 251             else {
 252                 if (open(CONS,">/dev/console")) {
 253                     print CONS "<$facility.$priority>$whoami: $message\r";
 254                     close CONS;
 255                 }
 256                 exit if defined $pid;           # if fork failed, we're parent
 257             }
 258         }
 259     }
 260 }
 261
 262 sub xlate {
 263     local($name) = @_;
 264     $name = uc $name;
 265     $name = "LOG_$name" unless $name =~ /^LOG_/;
 266     $name = "Sys::Syslog::$name";
 267     eval { &$name } || -1;
 268 }
 269
 270 sub connect {
 271     unless ($host) {
 272         require Sys::Hostname;
 273         my($host_uniq) = Sys::Hostname::hostname();
 274         ($host) = $host_uniq =~ /([A-Za-z0-9_.-]+)/; # allow FQDN (inc _)
 275     }
 276     unless ( $sock_type ) {
 277         my $udp = getprotobyname('udp')                 || croak "getprotobyname failed for udp";
 278         my $syslog = getservbyname('syslog','udp')      || croak "getservbyname failed";
 279         my $this = sockaddr_in($syslog, INADDR_ANY);
 280         my $that = sockaddr_in($syslog, inet_aton($host) || croak "Can't lookup $host");
 281         socket(SYSLOG,AF_INET,SOCK_DGRAM,$udp)           || croak "socket: $!";
 282         connect(SYSLOG,$that)                            || croak "connect: $!";
 283     } else {
 284         my $syslog = _PATH_LOG();
 285         length($syslog)                                  || croak "_PATH_LOG unavailable in syslog.h";
 286         my $that = sockaddr_un($syslog)                  || croak "Can't locate $syslog";
 287         socket(SYSLOG,AF_UNIX,SOCK_STREAM,0)             || croak "socket: $!";
 288         if (!connect(SYSLOG,$that)) {
 289             socket(SYSLOG,AF_UNIX,SOCK_DGRAM,0)          || croak "socket: $!";
 290             connect(SYSLOG,$that) || croak "connect: $! (SOCK_DGRAM after trying SOCK_STREAM)";
 291         }
 292     }
 293     local($old) = select(SYSLOG); $| = 1; select($old);
 294     $connected = 1;
 295 }
 296
 297 sub disconnect {
 298     close SYSLOG;
 299     $connected = 0;
 300 }
 301
 302 1;