#!/usr/bin/perl
# This script generates the trend graphs for the water reading with the
# Zoom feature for forensicsin the log files. It takes parameters "unit",
# two date text strings "from" and "to" for the time interval, and a "sample"
# argument that defines the display rendering.
# Arguments are passed to the script via the GET method, there are default
# values if no parameters are present.
# Naming convention for dates are whatever the date command in unix can
# parse, e.g. "3 days ago", "now", "20 Feb 2012" etc.
# Directories where the log files reside in
#$logdir="/home/chris/construction/BTUmetering/log";
#$gnudir="/home/chris/construction/BTUmetering/gnuplot";
$logdir="MAINPROGROOT/log";
$gnudir="MAINPROGROOT/gnuplot";
# Image directory:
#$imgdir="/srv/www/htdocs/img2";
$imgdir="HTDOCROOT/img2";
@allowedcores = ("AHU1", "AHU2", "AHU3", "S14L3", "AHU4", "AHU5", "AHU6", "PCW2");
# Following http://www.tutorialspoint.com/perl/perl_cgi.htm, we extract the
# parameters sent via get:
local ($buffer, @pairs, $pair, $name, $value, %FORM);
# Read in text
$ENV{'REQUEST_METHOD'} =~ tr/a-z/A-Z/;
if ($ENV{'REQUEST_METHOD'} eq "GET")
{
$buffer = $ENV{'QUERY_STRING'};
}
# sanitize input
$buffer =~ s/[^\w =&%:+-]//g;
# Split information into name/value pairs
@pairs = split(/&/, $buffer);
foreach $pair (@pairs)
{
($name, $value) = split(/=/, $pair);
$value =~ tr/+/ /;
$value =~ s/%(..)/pack("C", hex($1))/eg;
$value =~ s/[^\w :-]//g;
$FORM{$name} = $value;
}
# Extract the interesting ones
$core = $FORM{unit};
$starttime = $FORM{from};
$endtime = $FORM{to};
$sampling = $FORM{sample};
# TODO: We need to check if there are parameters supplied, otherwise supply
# defaults.
# Generate page header
print "content-type: text/html\n\n";
print "CQT utility consumption server
\n";
print "Data zoom view for heat load / CHW temperature
\n";
# Now, we need to check for parameter consistency.
$testerror=0;
if ($core eq "") { $core = "AHU1"; }
# test if unit exists
$matches = grep $core eq $_, @allowedcores;
if ($matches != 1) {
print "Error
Sorry, logging for this unit is not (yet) implemented.
\n";
$testerror=1;
}
# test if "to" date is parsable or replace by default
if ($testerror==0) {
# launder argument (do this later)
$et2=$endtime;
if ($et2 == "") {$et2 ="now"; $endtime=$et2;};
# retreive time in unix seconds
$et=`date -d \"$et2\" +"%s"`; chomp ($et);
# test if conversion was successful
if ( $et !~ /\d+/) {
print "Error
Could not interpret your \"to\" date specification.
\n";
$testerror=2;
}
}
# test if "from" date is parsable
if ($testerror==0) {
# launder argument (do this later)
$st2=$starttime;
if ($st2 == "") {$st2 ="1 month ago";$starttime=$st2;};
# retreive time in unix seconds
$st=`date -d \"$st2\" +"%s"`; chomp ($st);
# test if conversion was successful
if ( $st !~ /\d+/) {
print "Error
Could not interpret your \"from\" date specification.
\n";
$testerror=3;
}
}
# check if time interval is correctly oriented
if ($testerror==0) {
if ($st >= $et) {
print "Error
Your date range is empty or has the wrong direction.
\n";
$testerror=4;
}
}
# check if time interval overlaps with past
if ($testerror==0) {
$nw=`date +"%s"`; chomp($nw);
if ( $st gt $nw ) {
print "Error
Your date range ($st to $et) is referring to the future, but I can only make statements about the past.
\n";
$testerror=5;
}
}
# test if "sample" date is parsable
$sampling =~ s/[^\d]//;
if ($sampling eq "") { $sampling = 1; }
if ($sampling < 1) { $sampling = 1; }
# now we can generate the image and print out a link to it
if ($testerror==0) {
# convert unix time range into gnuplot time range
$ofs=`date -d "1 Jan 2000 00:00SGT" +"%s"`;
$stg=$st-$ofs; $etg=$et-$ofs;
# find out what part of the tail we need to use for speedup in display.
# For this, we calculate the num of minutes from start to now
$taillength=int(($nw-$st)/60.);
# For debugging
# $timespan=1;
# $core="AHU2";
# Prepare flexible arguments for gnuplot for different sizes
$imagename = $core."_zoom.png";
# compose parameter set for gnuplot
$parset="set xrange [$stg:$etg]; num=$taillength; ofmt=\"%H:%M\\n%m/%d\"; core=\"$core\"; evr=$sampling; outfilename=\"$imagename\"; logdir=\"$logdir\"; imgdir=\"$imgdir\" \n";
# generate image
open GNUPLOT, "| gnuplot - $gnudir/zoom.gnu >/dev/null";
print GNUPLOT $parset;
close GNUPLOT;
# Generate web page
print "![](\"/img2/".$imagename."\")
\n";
}
# Select other resolutions/ units
print "
Show other time span:
Format of the entries above:
The time specification can be anything that is understood by the unix date command, e.g. \"now\", \"11:25\", \"12:00 8 June\", \"last week\", \"23 Mar\" etc.
Sampling is the integer number of minutes are between different points on the graph. This helps to reduce noise in long periodes.
";
# Link to main page of this server
print "Back to main page.
";
# Finish html page
print "\n\n";