#!/usr/local/bin/perl
# *********************************************************************** #
# *									* #
# *                Copyright (c) 1996-1999 Scott Crevier		* #
# *                    All Rights Reserved Worldwide			* #
# *									* #
# *  This program product material is the property of Scott Crevier.	* #
# *  This program may be used and modified by anyone free of charge,	* #
# *  as long as this copyright notice remains in tact. By using this	* #
# *  code, you agree to indemnify Scott Crevier from any liability	* #
# *  that might arise from its use.					* #
# *									* #
# *     scott@crevier.org  -  Scott M. Crevier  -  www.crevier.org      * #
# *********************************************************************** #
# *  smcCount v2.0					21-Dec-1998	* #
# *									* #
# *  This program displays a simple text counter. The filename used to	* #
# *  store the counter value is based on the name of the html file	* #
# *  that called this script. Therefore, many different html files can	* #
# *  use this counter script and each one will have its own place to	* #
# *  store the value. The nice thing that I like about this method is	* #
# *  explained in the following example:				* #
# *									* #
# *  If my 'index.shtml' file uses this counter, the value will be	* #
# *  stored in the file 'index.shtml.cnt'. This allows me to include	* #
# *  the following code in my 'index.shtml':				* #
# *									* #
# *  This page was last accessed on					* #
# *  <!--#flastmod file="index.shtml.cnt"-->				* #
# *									* #
# *  As you can see, I am displaying the last modification time of the	* #
# *  counter file. Obviously, in order for this to work properly, you	* #
# *  need to do this before actually executing the counter script.	* #
# *									* #
# *  Suggested usage:							* #
# *  <!--#include virtual="/cgi-bin/smcCount"-->			* #
# *  or									* #
# *  <!--#exec cgi="/cgi-bin/smcCount"-->				* #
# *									* #
# *********************************************************************** #

# *********************************************************************** #
# *  Get the name of the file where the counter value is stored.	* #
# *  This will be the name of the file that called this script with	* #
# *  an extension of ".cnt". This file will also be stored in the same	* #
# *  directory as the file that called this script.			* #
# *  So, for example, if the file "index.shtml" called this script, 	* #
# *  then the counter will be stored in "index.shtml.cnt".		* #
# *********************************************************************** #
$filename = $ENV{'DOCUMENT_ROOT'} . $ENV{'DOCUMENT_URI'} . ".cnt";

# *********************************************************************** #
# *  If the counter file exists, we increment it and write it back. If	* #
# *  the counter file does not exist, we try to create it. The ability	* #
# *  to create the file will simply depend on the permissions of the	* #
# *  directory where the counter file will reside. If the file cannot	* #
# *  be created by this script, you'll have to create it manually. The	* #
# *  following two commands will do that just fine:			* #
# *									* #
# *    touch index.shtml.cnt						* #
# *    chmod a+w index.shtml.cnt					* #
# *********************************************************************** #
if (-e $filename) {
  #**************************************************************#
  #*  The counter file exists so we need to increment it.	*#
  #**************************************************************#
  if (open (FILE, "+<$filename")) {
      #******************************************#
      #*  Lock the counter file.		*#
      #******************************************#
      flock (FILE, 2);

      #******************************************#
      #*  Get the current counter value.	*#
      #******************************************#
      $counter = <FILE>;

      #******************************************#
      #*  Write the incremented value back to	*#
      #*  the file. 				*#
      #******************************************#
      seek(FILE,0,0);
      print (FILE ++$counter);

      #******************************************#
      #  Release the lock, then close the file.	*#
      #******************************************#
      flock (FILE, 8);
      close (FILE);
  } else {
      #******************************************#
      #*  This means that the file exists but	*#
      #*  we do not have permission to write.	*#
      #******************************************#
      print "Sorry pal, can't write to file '$filename'. Counter not incremented!", "\n";
  }
} else {
  #**************************************************************#
  #*  The counter file does not exist so we need to create it.	*#
  #**************************************************************#
  if (open (FILE, ">" . $filename)) {
      #******************************************#
      #*  Lock the counter file.		*#
      #******************************************#
      flock (FILE, 2);

      #******************************************#
      #*  Set the counter to 1.			*#
      #******************************************#
      $counter = 1;

      #******************************************#
      #*  Write the value back to the file.	*#
      #******************************************#
      print (FILE $counter);

      #******************************************#
      #  Release the lock, then close the file.	*#
      #******************************************#
      flock (FILE, 8);
      close (FILE);
  } else {
      #******************************************#
      #*  This means that the file does not	*#
      #*  exist and we do not have permission	*#
      #*  to create it.				*#
      #******************************************#
      print "Sorry pal, can't create file $filename. Counter not incremented!", "\n";
  }

}

# *********************************************************************** #
# *  Print the counter value.						* #
# *********************************************************************** #
print	"Content-type: text/plain", "\n\n", $counter;

exit (0);