nch-devel

[Shachar S. <nc...@sh...>]

Hi list

Version 0.02 was just released. The most major change in terms of 
functionality is the addition of variables support. The format for the 
protocol file has also somewhat changed.

The format is as follows:
Alternating "directions" - whatever is written at the begining of the 
file is sent upon connection establishment. Then, NetChat waits for 
what's written in the second state. When that is received, it sends 
what's written in the third state, and so on.
Changing states, as well as doing some other tasks, is performed by 
putting in special chars in an escape sequence. The escape character is 
"$". In order to put "$" verbatim, you need to double it ($$ causes one 
$ to be sent). A command starts with the sequence $. (dollar period), 
and ends with either . (period) or a newline. Following the period is a 
single letter signifying to command to take. At the moment, just two 
commands are available:
E - End state
V - Variable

End state - this means that the current state has ended. Data between 
the last $.E command and the end of the file is ignored.
Variable - the var is followed by a name of a file. Each line in the var 
file is a single instance of the var. When the file is exhusted, it 
starts over. Due to the format of the parser, the file name may not 
contain a period.

Sample file http.nch:
The file begins with a URL to send:
GET /$.Vurl. HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; M$$IE 6.0; Window$$ 98)
Host: localhost

A few points to notice:
1. The content of the URL is taken from a variable. NetChat will look 
for a file called "url", and will take the list of URLs to look for from 
there.
2. In the user agent string, since we wanted to put in the dollar sign, 
we had to double it.

The state ends with a state end command "$.E". The command termination 
in this case is by a newline, while it was a period in the case of $.V 
above. Choose whatever best suites your asthetic values.

          Shachar

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/