#!/usr/local/bin/perl

#Aggemam Text Counter(tm) by Simon Skals
#
#This is version 1.2 patchlevel 3
#
#Feel free to modify this script, call it your own, or whatever.
#You can mail me at aggemam@gid.dk and be subsequently ignored.
#
#The most recent version of this script can always be found at this URL:
#Aggemam homepage http://www.gid.dk/~simon/
#
#DESCRIPTION:
#Aggemam Text Counter is a simple text counter that requires SSI. For good
#measure, it logs the IP address of the last visitor and the counter will not
#increment until it is fetched by a new IP.
#
#INSTALLATION:
#Installation should be easy. Just copy the script into your cgi-bin and
#chmod it to 755. Touch the files counter.dat and hostname.dat in whatever
#location you've chosen for them. Remember to make them readable and writable
#for the world.
#
#Finally, just stick this piece of SSI in your HTML:
#   <!--#exec cgi="/cgi-bin/aggemam.pl"-->
#
#Please note that this script will suck if your system doesn't support flock.
#
#CONFIGURATION:
#Set this variable to the directory where you want to store the data files. 
#Be careful not to add a final trailing slash.

$datadir="/usr/home/yourlogin/somedir";

#Ok, let's get to work.
#Prepare for HTML output.

print "Content-type: text/html\n\n";

#Get the REMOTE_HOST variable to find out who's hitting the page. 

$host = $ENV{'REMOTE_HOST'}; 

#Open the file counter.dat to find out the current value of the counter.

open (counter, "<$datadir/counter.dat") || &error("Ouch, could not open $datadir/counter.dat.");

flock counter, 2; 

$counter = <counter>;

close (counter);

#Next we've got to open the file hostname.dat to see the latest hostname to
#hit the page.

open (hostname, "<$datadir/hostname.dat") || &error("Ouch, could not open $datadir/hostname.dat.");

flock hostname, 2; 

$oldhost = <hostname>;

close (hostname);

#Check whether these two hostnames are identical.

if ($host eq $oldhost) {

#If they're identical, we don't want the counter to increase. Instead we just
#print the current value that we got from counter.dat.

print "$counter";
	
exit;   

} else {

#If they're not identical, we want to increase the counter with 1 and save this
#value to counter.dat. Then we save the new hostname to hostname.dat. Finally,
#we print the new value of the counter.

$counter++;

open (newcounter, ">$datadir/counter.dat") || &error("Ouch, could not open $datadir/counter.dat.");

flock newcounter, 2; 

print newcounter "$counter";

close (newcounter);

open (newhostname, ">$datadir/hostname.dat") || &error("Ouch, could not open $datadir/hostname.dat.");

flock newhostname, 2;

print newhostname "$host";

close (newhostname);

print "$counter";

exit;

}

#Here's the subroutine we use in case something went haywire. 

sub error {

$descr = $_[0] ;

print "[$descr $!.]";

exit;

}