#! /usr/bin/perl -w
#############################################################################
#
# makeplot.pl
#
# Creates a plotfile of the load of the machine. The plot ranges 12 hours
# back in time and is sampled at 2 minutes interval.
#
# Changes:
#    29.11.1998, chakie - first version.
#
# $Id: makeplot.pl,v 1.1 1998-11-30 18:02:48+02 chakie Exp $
#############################################################################

#
# declare the stuff we'll use
use CGI;

#
# set some global variables
$OutDir   = '/home/chakie/www/load';
$OutWWW   = '~chakie/load';
$BaseName = `date '+%Y.%m.%d-%H.%M'`;
$OutName  = $OutDir . '/plot-' . $BaseName;
$OutNameWWW = '/plot-' . $BaseName;
$DataDir  = '/home/chakie/var/loadavg';

# define the name of the datafile
$Options = $OutDir . "/plotoptions";

# define the intervals
$Hours = 24;

# get the current time
$CurrentYear   = `date '+%Y'`;
$CurrentMonth  = `date '+%m'`;
$CurrentDay    = `date '+%d'`;
$CurrentHour   = `date '+%H'`;
$CurrentMinute = `date '+%M'`;

# gut away the trailing \n
chomp $CurrentYear;
chomp $CurrentMonth;
chomp $CurrentDay;
chomp $CurrentHour;
chomp $CurrentMinute;
chomp $OutName;
chomp $OutNameWWW;


#############################################################################
#
#############################################################################
sub readFile {

	my $File = $_[0];
	my $Data;

	# does the file exist?
	if ( ! -e $File ) {
		# no such file, ignore
	}

	else {
		# file exists, so open it
		open FILE, $File || die "Can't open " . $File . ", aborting.\n";
		
		# read from the file
		while ( <FILE> ) {
			# parse the data
			/(\d\d) (\d\.\d\d) (\d*)/;
			
			# now scale the time from [0..60] to [0..100]
			push @Data, $3;
			push @Data, $2;
		}

		# we're done, close the file
		close FILE;
	}

	# return the data
	return @Data;
}


#############################################################################
# Writes the data in one hour to the output-file
#############################################################################
sub writeHour {

	my $File = shift;
	my $Hour = shift;
	my @Data = @_;

	$Total = ($#Data + 1) / 2; 

	# loop over all values in the file
	for ( $Index = 0; $Index < $Total; $Index++ ) {
		# create the hour
		$Time  = sprintf "%02d.%02d", $Hour, ($Index / 30) * 100;
		$Users = shift @Data; 
		$Load  = shift @Data; 
	   
		# write the entry
		print $File $Time . " " . $Load . " " . $Users . "\n";
	}
}


#############################################################################
#
#############################################################################
sub createFileName {

	# create the fileame from passed strings
	my $File = sprintf "%d.%02d.%02d-%02d", $_[0], $_[1], $_[2], $_[3];

	# return it
	return $File;
}


#############################################################################
# Main program
#############################################################################

# create a new CGI object
$Query = new CGI;

# create the header
print $Query->header;
print $Query->start_html ( -title => 'infa.abo.fi load',
						   -bgcolor => 'white' );

#
# print s nice header
print "<center>";
print $Query->h1 ( 'infa.abo.fi load' );
print "</center>";

#
# print the actual information
print "<center>Local time is: <b>" . `date` . "</b></center><p>";

# open the destination-file
open TARGET, '>' . $OutName || die "Can't open output file '" . $OutName . "', aborting.\n";

#
# ok, now loop for the proper number of hours
for ( $Hour = 0; $Hour < $Hours - 1; $Hour++ ) {

	# create the file for this hour
	$File = $DataDir . '/' . createFileName ($CurrentYear, $CurrentMonth, $CurrentDay, $Hour);

	# clear the array first and then get data from the file
	undef @Data;
	@Data = readFile ( $File  );

	# write out the data to out file
	writeHour ( \*TARGET, $Hour, @Data );
}


# we're done with the file
close TARGET;

# open the options-file
open OPTIONS, '> ' . $Options || die "Can't open options file " . $Options . "\n";

# write our options to the file
print OPTIONS << 'EOF';

set term png small color
set nolog
set nopolar
set border
set xrange [0:24]
set y2range [0:]
set xtics 0, 1, 24
set xtics 0, 1, 24
set y2tics 2
set grid
set title  "Load average and users"
set xlabel "Time (h)"
set ylabel "Load"
set y2label "Users"

set size 1, 1
set origin 0, 0

EOF

# print the actual 'plot' command
print OPTIONS 'plot "' . $OutName . '" using 1:2 title "Load" with line 1, ';
print OPTIONS '"' . $OutName . '" using 1:3 axes x1y2 title "Users" with line 3';

# close the file
close OPTIONS;

# run 'gnuplot' over the file
system 'gnuplot ' . $OutDir . '/plotoptions > ' . $OutName  . '.png';

# print out the image
print '<center><img src="http://www.infa.abo.fi/' . $OutWWW . $OutNameWWW . '.png"></center>';

# create the footer
print $Query->hr;
print '<p>';
print '<i><center>For more information contact ';
print '<a href="mailto:chakie@infa.abo.fi">Chakie</a></center></i>';
print $Query->end_html;