#!/usr/bin/perl

#**********************************************************************
#* Program:      Image Randomizer from Radiation                      *
#* Version:      1.0                                                  *
#* Author:       Andrew Cowan (icculus@radiation.com) for Radiation   *
#* Date:         January 7, 1997                                      *
#* Product Info: http://www.radiation.com/gizmos/random.html          *
#*                                                                    *
#* This program is the copyrighted property of Radiation, a venture   *
#* of GlobalMedia Design. Any use of this program is subject to the   *
#* the terms of the license agreement (LICENSE.TXT) included as part  *
#* of this distribution archive. Any other uses are stictly           *
#* prohibited without the written permission of GlobalMedia Design    *
#* and all other rights are reserved.                                 *
#*                                                                    *
#* Support for this software is available only to registered users.   *
#* For registration information, consult the REGISTER.TXT document    *
#* included as part of this distribution archive, or visit the Gizmos *
#* section of the Radiation website at:                               *
#*                                                                    *
#*                http://www.radiation.com/gizmos/                    *
#*                                                                    *
#**********************************************************************

# ************************************************************************
# USAGE:
#
# Just drop the script into a CGI accessible directory, make it executable
# and make sure the perl location at the top is correct.
#
# Information is passed to the script via form fields passed in the url.
#
# Fields:
# dir -   The absolute directory location of the images directory
# type -  Either GIF or JPG, depending on which image type you want
#
# So, an example call to the script:
#
# http://www.host.com/cgi-bin/random_image.cgi?dir=/www/htdocs/images&type=GIF
# http://www.metrarail.com/cgi/random_image.cgi?dir=Rotate/images&type=JPG
# ************************************************************************
# Main Routine
# ************************************************************************

&cgiparse;
&startup;
&grab_image;
&print_image;

exit(0);

# ************************************************************************
# Subroutine Declarations
# ************************************************************************

sub startup{

   # Get the given form fields

   $dir = $elements{'dir'};
   $type = $elements{'type'};

}

sub grab_image{

   # Grab all files in the given directory

   opendir(DIR, "$dir");
   local(@temp_files) = readdir(DIR);
   closedir(DIR);

   # Grab only appropriate files based on type of image file

   foreach $file (@temp_files){
      if ($type eq "GIF"){
	 if ($file =~ /\.gif$/){ push(@file_list, $file); }
      }elsif (($type eq "JPEG") || ($type eq "JPG")){
	 if ($file =~ /\.jpe?g$/){
	    push(@file_list, $file); 
	 }
      }else{
	 if ($file =~ /\.jpe?g$/){
	    push(@file_list, $file);
	 }
      }
   }

}

sub print_image{

   # Determine number of images

   local($num_images) = $#file_list + 1;

   # Grab a random number based on number of image files

   srand;
   local($index) = int(rand($num_images));

   # Construct full filename using given directory

   local($filename) = $dir . "/" . $file_list[$index];

   # Determine and print the proper content type

   if ($filename =~ /\.gif$/){
      print "Content-type: image/gif \n\n";
   }elsif ($filename =~ /\.jpe?g$/){
      print "Content-type: image/jpeg \n\n";
   }

   $| = 1;  # Force flush after a write

   # Read the file and print line by line, flushing as we go

   open(IMAGE, "$filename");
   while(<IMAGE>){ print; }
   close(IMAGE);

}


# ************************************************************************
# Urldecode Routines
# ************************************************************************
# Copyright & Disclaimer. (James Tappin)
#       The following set of routines may be freely distributed, modified 
#       and used, provided this copyright & disclaimer remains intact.
#       This package is used at your own risk, if it does what you
#       want, good; if it doesn't, modify it or use something else--but
#       don't blame me. Support level = negligable (i.e. mail bugs but
#       not requests for extensions)
# ************************************************************************

sub cgiparse {

  if ($ENV{'REQUEST_METHOD'} eq "POST") {
	read(STDIN, $data, $ENV{'CONTENT_LENGTH'});
  }
  elsif ($ENV{'REQUEST_METHOD'} eq "GET") {
	$data = $ENV{'QUERY_STRING'};
  }
  else {
	#
	#  Bad request method report and exit.
	#
	&method_error;
  }

  %elements = &url_decode(split(/[&=]/,$data));
  %elements;
}

sub method_error {

  print "\nCGI Script Requires use of method POST or GET.\n";
  exit;
}


sub url_decode {

    foreach (@_) {
        tr/+/ /;
        s/%(..)/pack("c",hex($1))/ge;
    }
    @_;
}
1;