Line # Revision Author
1 760 ahitrov #!/usr/bin/env perl
2 8 ahitrov@rambler.ru
3 ##############################################################################
4 # $HeadURL: http://svn.dev.rambler.ru/Contenido/branches/utf8/services/logtail $
5 # $Id: logtail 1291 2008-11-10 13:25:19Z phoinix $
6 #
7 # Удобно мониторить логи, например поставить в crontab:
8 # */5 10-19 * * * logtail /.../error_log ~/tmp/error_log.off
9 ##############################################################################
10
11 use strict;
12 use warnings 'all';
13
14 use File::stat;
15 use FindBin;
16
17
18 if ($#ARGV<0 || $#ARGV>1) {
19 &usage;
20 exit 1;
21 }
22
23 my $log_file = $ARGV[0];
24 my $offset_file = $ARGV[1] || "$log_file.offset";
25
26 my $stat = stat($log_file) or die "Can't stat $log_file - $!";
27
28 my ($prev_size, $prev_ino);
29 if (-f $offset_file) {
30 open OFF, "< $offset_file" or die "Can't read offset_file - $!";
31 $prev_size = <OFF>;
32 $prev_ino = <OFF>;
33 close OFF;
34 }
35 $prev_size = 0 unless $prev_ino==$stat->ino && $prev_size<=$stat->size;
36
37 exit if $prev_size==$stat->size;
38
39 open LOG, "< $log_file" or die "Can't read log - $!";
40 seek LOG, $prev_size, 0 or die "Can't seek - $!";
41 my $buf;
42 my $readed = read LOG, $buf, $stat->size - $prev_size;
43 close LOG;
44 die "Can't read log_file - $!" unless $readed;
45
46 print $buf;
47
48 open OFF, "> $offset_file" or die "Can't write offset_file - $!";
49 print OFF $stat->size."\n".$stat->ino."\n$log_file\n".localtime()."\n";
50 close OFF;
51
52
53 sub usage {
54 print <<EOM;
55 Usage:
56 $FindBin::Script logfile [offset.file]
57 EOM
58 }