lwes-perl-journal-listener

   1 #!/usr/bin/env perl
   2
   3 use strict;
   4 use warnings;
   5
   6 use Getopt::Long;
   7 use Pod::Usage;
   8 use LWES::EventParser;
   9 use LWES::Listener;
  10 use POSIX qw(strftime);
  11
  12 my $help_opt         = 0;
  13 my $man_opt          = 0;
  14 my $verbose_opt      = 0;
  15 my $stats_opt        = 0;
  16
  17 Getopt::Long::Configure ("pass_through");
  18
  19 GetOptions
  20   (
  21     'help'           => \$help_opt,
  22     'man'            => \$man_opt,
  23     'stats'          => \$stats_opt,
  24     'verbose'        => \$verbose_opt,
  25   ) or pod2usage (2);
  26
  27 pod2usage (-exitval => -1, -verbose => 0) if $help_opt;
  28 pod2usage (-exitval => -2, -verbose => 2) if $man_opt;
  29
  30 my $listener_or_code;
  31
  32 # if the first argument is a file, we'll assume it s a journal file, and
  33 # use the PrintingListener
  34 if (-f $ARGV[0])
  35   {
  36     $listener_or_code = "LWES::Listeners::EventPrintingListener";
  37   }
  38 else
  39   {
  40     $listener_or_code = shift @ARGV;
  41   }
  42
  43 # determine the callback which will process each event
  44 my $processEventFunc = getProcessEventFunc ($listener_or_code, \@ARGV);
  45
  46 foreach my $journal (@ARGV)
  47   {
  48     my $start       = time();
  49     my $num_events  = 0;
  50     my $num_success = 0;
  51     my $num_error   = 0;
  52
  53
  54     if (-f $journal)
  55       {
  56         open FH, "zcat $journal |";
  57
  58         # read and parse header
  59         my $header_bytes;
  60         while ( read (FH, $header_bytes, 22) == 22)
  61           {
  62             my $header = bytesToHeader ($header_bytes);
  63
  64             # read and parse bytes
  65             my $event_bytes;
  66             my $n = read (FH, $event_bytes, $header->{'PayloadLength'});
  67             if (defined ($n) && $n == $header->{'PayloadLength'})
  68               {
  69                 my $event = bytesToEvent ($event_bytes);
  70
  71                 # merge header into event
  72                 foreach my $h (keys %{$header})
  73                   {
  74                     unless (exists ($event->{$h}))
  75                       {
  76                         $event->{$h} = $header->{$h};
  77                       }
  78                   }
  79
  80                 # call handler
  81                 my ($success, $errors) = $processEventFunc->($event);
  82                 $num_events++;
  83                 if (defined ($success))
  84                   {
  85                     $num_success += $success;
  86                   }
  87                 if (defined ($errors))
  88                   {
  89                     $num_error   += $errors;
  90                   }
  91               }
  92             else
  93               {
  94                 die "malformed or truncated journal";
  95               }
  96           }
  97
  98         close FH;
  99       }
 100
 101     if ($stats_opt)
 102       {
 103         my $log_date   = strftime ("%a %b %e %H:%M:%S %Y", localtime (time()));
 104         my $end = time()-$start;
 105         print "$log_date : $journal had $num_events events processed with $num_success successful actions and $num_error errors in $end seconds\n";
 106       }
 107   }
 108
 109 0;
 110
 111 __END__
 112
 113 =head1 NAME
 114
 115 lwes-perl-journal-listener - listens for events from a journal
 116
 117 =head1 SYNOPSIS
 118
 119 lwes-perl-journal-listener [options] [<listener> [<args>] | <code>] <journal(s)>
 120
 121 Options:
 122   --stats                     Print information about each file processed
 123   -help                       Brief help message
 124   -man                        Full Documentation
 125
 126 <listener> is the name of a perl module which extends the base
 127 listener LWES::Listener and provides an initialize and processEvent
 128 method.  The <args> are passed directly to the listener constructor.
 129
 130 code is perl code which is embedded in a function which takes one
 131 argument, a reference to a perl hash which contains the contents
 132 of the event called $event
 133
 134 =head1 OPTIONS
 135
 136 =over 8
 137
 138 =item B<--stats>
 139
 140 Print information about how many events were processed and how long it took
 141 to process.
 142
 143 =item B<-help>
 144
 145 Print help information
 146
 147 =item B<-man>
 148
 149 Print more verbose help information
 150
 151 =back
 152
 153 =head1 DESCRIPTION
 154
 155 The lwes-perl-journal-listener is a tool for inspecting LWES events that
 156 are in journal files created by the lwes-journaller.
 157
 158 There are several ways to use the tool.  To just print out events as they
 159 are seen it can be invoked as
 160
 161 % lwes-perl-journal-listener <journal>
 162
 163 Alternatively you can provide a LWES::Listener module as outlined in
 164 the lwes-perl-event-listener man page.
 165
 166 =cut