#!/usr/bin/perl
# HOW comes from Html-On-the-Web
# written by Aytekin Tank, 1999
# make sure to read "how.txt"

 # you dont need to modify anything in this file 
 # but if you change the names of these files
 # make sure change here too.
 $how_temp = "how_temp.htm";
 $list_file = "temp_list.txt";

 # tell browser that this will be an html file
 print "Content-type: text/html\n\n";
 # get the input from the form:
 &readparse;	
 # put the header in its place
 &start;
 
 # get the password and the list of the files
 # from our small config file: 
 open (TEMP, "<$list_file");
 $password = <TEMP>;
 while(($thisrow = <TEMP>))
 { if($thisrow ne "\n")
   { push(@files, join("", split("\n", $thisrow))); }}
 close TEMP;
 
 # check for password, if wrong bye bye!
 if ($password eq "")
 { print "\n\n<br>something is wrong with $list_file"; &end; }
 chomp($password);

 # The form above to select the file to be modified:
 if ($password ne $input{'password'} )
 {
 	print "<p><br> <blockquote>";
 	print "<form action=how.cgi method=post>password: ";
	print "<input type=text size=10 name=password>";
	&pull_down;
	print "<INPUT type=submit name=submit value=how?></form>"; 
	&end;
 }
 
 # modified file is being replaced with the older one:
 if ($input{'file'} ne "")
 {
	$html = $input{'html'};
        $html =~ s/\<\*textarea\>/<\/textarea>/;    
  	open (FILE, ">$input{'file'}");
 	print FILE $html; 
  	close FILE;
 }
 
 # the forms and html stuff
 print "<p> <blockquote>\n";
 print "<form action=how.cgi method=post>\n";
 print "<input type=hidden size=10 name=password value=$input{'password'}>\n";
 &pull_down;
 print "<INPUT type=submit name=submit value=how?> </form>\n"; 
 print "<form action=how.cgi method=post>\n";
 print "<input type=hidden name=file value=$input{'selected'}>\n";
 print "<input type=hidden size=10 name=password value=$input{'password'}>\n";
 print "File: <a href=$input{'selected'}>$input{'selected'}</a>\n";
 print "<textarea name=html rows=20 cols=60 wrap=soft>\n";
 &get_file;
 print "</textarea> \n";
 &pull_down;
 print "<INPUT type=submit name=submit value=Modify> \n";
 print "<INPUT type=reset name=reset value=Reset> \n";
 print "</form><p><br>\n"; 
 
&end;

 # This places the file into the textarea.
 # </textarea> inside the textarea give me a little headache
 # because of its premature ending.
 # But I solved it like this: 
sub get_file
{
 open (FILE, "<$input{'selected'}");
 while(($thisrow = <FILE>))
 {
   $thisrow =~ s/\<\/textarea\>/\<\*textarea\>/;  
   print $thisrow; 
 }
 close FILE;
}  
 
 # the pull down menu:
sub pull_down
{
 print " <p><b> <blockquote>\n";
 print " <select name=selected size=1>\n";
 print " <option selected value=$input{'selected'}> $input{'selected'} </option>\n";
 foreach $file(@files)
 { print "<option value=$file> $file </option>\n"; }
 print "</select>\n";
} 
 
 # the header
sub start
{
  open (HOWTEMP, "<$how_temp");
   while(($thisrow = <HOWTEMP>))
   { push(@howtemplate, $thisrow); }
  close HOWTEMP;
 @howtemplate = split("%%HOW HERE%%", join("\n", @howtemplate));
 print $howtemplate[0];
}

 # the end of the html text
sub end
{
 print $howtemplate[1];
 exit;
} 

###############################
# FORM PARSE
###############################
sub readparse {
	read(STDIN,$user_string,$ENV{'CONTENT_LENGTH'});
	if (length($ENV{'QUERY_STRING'})>0)
{$user_string=$ENV{'QUERY_STRING'}};
	$user_string =~ s/\+/ /g;
	@name_value_pairs = split(/&/,$user_string);
	foreach $name_value_pair (@name_value_pairs) {
	        ($keyword,$value) = split(/=/,$name_value_pair);
	        $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/ge;
	  $input{$keyword} = $value;
	}
}