====== Directory structure with permissions ======

The file permissions are the same as were there on lthcwww. \\
The directory %%"/var/www/demos/ensembles"%% has permission \\

<code>
drwxrwsr-x  4 rathi  ipgdemos 4096 2008-08-05 13:56 ensembles 
</code>

This is the directory structure of %%"/var/www/demos/ensembles"%% \\
with permissions. \\

<code>
-rw-rw-r-- 1 rathi ipgdemos 12892 2008-08-15 20:16 index.php
-rw-r--r-- 1 rathi ipgdemos  5628 2008-08-11 17:56 lthc_index.php
-rwxrwxrwx 1 rathi ipgdemos 82987 2008-08-12 00:48 makegraph
-rwxrwxrwx 1 rathi ipgdemos 13697 2008-08-12 02:12 plotgraph
drwxrwsr-x 2 rathi ipgdemos  4096 2008-08-15 18:44 programs
drwxrwsr-x 2 rathi ipgdemos  4096 2004-02-23 00:22 psfiles
</code>
The file %%"lthc_index.php"%% has the old lthc way of giving inputs. \\
**Note that I had to give makegraph and plotgraph %%"-rwxrwxrwx"%%**. Otherwise, \\
the web page is not working.


The directory %%"/var/www/demos/ensembles/programs"%% contains the C source code. \\
The file permissions for files inside directories  %%"programs"%% are same as \\
that on lthcwww and are given by
<code>
[rathi@iscsrv32 ensembles]$ ls -l programs/
total 224
-rw-rw-r-- 1 rathi ipgdemos   182 2004-02-21 16:08 channel.h
-rw-rw-r-- 1 rathi ipgdemos  1103 2004-02-21 16:08 decode.h
-rw-rw-r-- 1 rathi ipgdemos 28026 2004-02-21 16:06 encode.c
-rw-rw-r-- 1 rathi ipgdemos   891 2004-02-21 16:06 encode.h
-rw-rw-r-- 1 rathi ipgdemos 48240 2004-02-21 16:06 graph.c
-rw-rw-r-- 1 rathi ipgdemos  3678 2004-02-21 16:06 graph.h
-rw-rw-r-- 1 rathi ipgdemos   238 2004-02-21 16:07 Makefile
-rwxrwxr-x 1 rathi ipgdemos 82987 2008-08-12 01:05 makegraph
-rw-rw-r-- 1 rathi ipgdemos  2533 2008-08-12 01:05 makegraph.c
-rwxrwxr-x 1 rathi ipgdemos 13697 2008-08-12 02:07 plotgraph
-rw-rw-r-- 1 rathi ipgdemos  3500 2008-08-12 02:07 plotgraph.c
-rw-rw-r-- 1 rathi ipgdemos   221 2004-02-21 16:08 sim.h
-rw-rw-r-- 1 rathi ipgdemos  4166 2004-02-21 16:06 sub.c
-rw-rw-r-- 1 rathi ipgdemos   471 2004-02-21 16:06 sub.h
-rw-r--r-- 1 rathi ipgdemos     0 2008-08-15 18:44 wc
</code>

**Path dependency:** In the files %%"makegraph.c"%% and %%"plotgraph.c"%%, \\
the path %%"/var/www/demos/files/ensembles"%% is specified to write the session \\
files.


The directory %%"/var/www/demos/ensembles/psfiles"%% contanins the \\
required files to generate the ps file. The permission for the directory \\
%%"psfiles"%% in the ensembles are the same as that on lthcwww and are \\
given by
<code>
[rathi@iscsrv32 ensembles]$ ls -l psfiles/
total 12
-rw-rw-r-- 1 rathi ipgdemos  235 2004-02-20 17:30 plotheader.ps
-rw-rw-r-- 1 rathi ipgdemos 1938 2004-02-20 17:30 plotmidsection.ps
-rw-rw-r-- 1 rathi ipgdemos   24 2004-02-20 17:30 plottrailer.ps
</code>



====== Important lines in index.php ======

Line 33 to 400: The code is about checking the validity of the polynomials.\\
Line 571 to 584: parameters are written.\\
Line 585 to 593: System commands to generate, plot in ps and convert to gif.\\
Line 622: Rate computation using the file %%"/var/www/demos/files/ensembles/tempa"%%.\\
Line 648: The graph file residing in %%"/var/www/demos/files/ensembles/"%% displayed \\
in the text format. 


====== Location of files related to execution and writing ======

The directory %%"/var/www/demos/files/ensembles"%% contains files for a \\
session. There are four files for a seesion and there names are suffixed \\
by session id's.
  * **param** contains the parameter of the ensembles.
  * **graph** contains the graph connections.
  * **tempa** data for rate computation.
  * **tempb** graph connections to generate the ps file of the graph.
All these four files have permissions: %%"-rw-r--r--"%%. The %%".gif"%% and \\
%%.ps%% are given names which are same as the session ids. They reside in \\
%%"/var/www/demos/files/ensembles/images"%% with permissions %%"-rw-r--r--"%%.




=====Important Remark=====

There should be a %%"crone"%% job deleting the files in %%"/var/www/demos/files/ensembles"%%.\\
The file names start with %%"graph, param, tempa, tempb"%%. There are four files without \\
the session d suffix which should not be deleted. These should be there just for the sake \\
of reference. Similarly, the files in %%"/var/www/demos/files/ensembles/images"%% should be \\
deleted.