#!/usr/bin/perl
# logreporter - Brian Edmonds <edmonds@cs.ubc.ca> 94Oct27

# template file directives:
#
# [IGNORE]
#   - all lines matching patterns until the next directive are ignored.
#
# [REPORT -> report message here]
#   - if the pattern following this directive matches a line, the
#     report message will be output; $d is bound to the first 15
#     characters of the matched line (the timestamp for syslog) when
#     the report message is evaluated.
#
# [COUNT -> report message here]
#   - the number of lines in the file which match the pattern following
#     this directive will be reported using the given report message,
#     if greater than zero; $n is bound the the number of matching lines
#     when the report message is evaluated.
#
# [SUM $X -> report message here]
#   - the numeric subfield $X (e.g. $1, $2, etc) of lines which match
#     the pattern following this directive will be summed and reported
#     using the given report message; $s is bound to the sum, and $n is
#     bound to the number of matching lines when the report message is
#     evaluated
#
# Remember that pattern lines are Perl regular expressions.  In
# particular remember to escape the special characters $^()[]+* or you
# won't get the effect you want.

# check our args
require 'getopts.pl'; $usage = "usage: $0 template [logfile]";
&Getopts( 'd' ) || die "$usage\n";
$#ARGV >= 0 || die "$usage\n";

# init
$state = 0;
$ignore = 0; $ignored = 0;
@count = ();
$reports = ""; $unknown = "";

# read the template
open( TEMPLATE, "<".shift ) || die "fatal: cannot read template\n";
while( $line = <TEMPLATE> ) {
    $line !~ /^\s*#|^\s*$/ || next;
    chop $line;

    # log entries to ignore
    if( $line =~ /^\[IGNORE\]/ ) {
	$state = "IGNORE";
    }

    # report on this line
    elsif( $line =~ /^\[REPORT -> (.*)\]/ ) {
	$state = "REPORT";
	$stmsg = $1;
    }

    # count occurances of this line
    elsif( $line =~ /^\[COUNT -> (.*)\]/ ) {
	$state = "COUNT";
	$stmsg = $1;
    }

    # sum a number in this line
    elsif( $line =~ /^\[SUM (\S*) -> (.*)\]/ ) {
	$state = "SUM";
	$sumvar = $1; $stmsg = $2;
    }

    # ooh, real data
    else {
	if( $state eq "IGNORE" ) {
	    if( $ignore ) { $ignore .= "|" . $line }
	    else { $ignore = $line }
	} elsif( $state eq "REPORT" ) {
	    $repmsg[++$#repmsg] = $stmsg . "\n";
	    $repregex[++$#repregex] = $line;
	} elsif( $state eq "COUNT" ) {
	    $countmsg[++$#countmsg] = $stmsg . "\n";
	    $countregex[++$#countregex] = $line;
	    eval "\$count$#countregex = 0";
	} elsif( $state eq "SUM" ) {
	    $summsg[++$#summsg] = $stmsg . "\n";
	    $sumregex[++$#sumregex] = $line;
	    $sumvar[++$#sumvar] = $sumvar;
	    eval "\$sumcount$#sumregex = 0";
	    eval "\$sumsum$#sumregex = 0";
	}
    }
}
close TEMPLATE;

# print out our regexps
if( $opt_d ) {
    print "Ignore regex:\n$ignore\n\n";
    print "Count rexexps ($#countregex):\n";
    for( $i=0 ; $i<=$#countregex ; $i++ ) {
	print $countregex[$i], "\n";
	print " -> ", $countmsg[$i];
    }
    print "\n";
}

# do the log
loop: while( $line = <> ) {
    $done = 0;

    for( $i=0 ; $i<=$#countregex ; $i++ ) {
	next unless $line =~ /$countregex[$i]/;
	eval "\$count$i++"; $done = 1;
    }

    for( $i=0 ; $i<=$#sumregex ; $i++ ) {
	next unless $line =~ /$sumregex[$i]/;
	eval "\$sumsum$i += $sumvar[$i]";
	eval "\$sumcount$i++"; $done = 1;
    }

    for( $i=0 ; $i<=$#repregex ; $i++ ) {
	next unless $line =~ /$repregex[$i]/;
	$d = substr( $line, 0, 15 );
	$reports .= "  " . eval "\"$repmsg[$i]\"";
	$done = 1;
    }

    if( ! $done ) {
	if( $line =~ /$ignore/o ) { $ignored++ }
	else { $unknown .= $line }
    }
}

$count = "  $ignored routine messages ignored\n";
for( $i=0 ; $i<=$#countregex ; $i++ ) {
    if( $n = eval "\$count$i" ) {
	$count .= "  " . eval "\"$countmsg[$i]\"";
    }
}
for( $i=0 ; $i<=$#sumregex ; $i++ ) {
    if( $n = eval "\$sumcount$i" ) {
	$s = eval "\$sumsum$i";
        $count .= sprintf( "  " . eval "\"$summsg[$i]\"", $s );
    }
}

# generate report
print "\nSummary reports:\n$count";
if( $reports ) { print "\nIndividual reports:\n$reports" }
if( $unknown ) { print "\nUnknown entries:\n$unknown" }

# EOF