README

=======================================================

file: README
Created by: Krishnashish Gogoi
Copyright 2013 Krishnashish Gogoi
Licensed under GPLv3


Yeah, I just wrote all that stuff to look cool.

========================================================

You can check the original README file in the original/ directory.



=== Introduction ===

smsh is an application that basically allows you to control your
Linux machine remotely through SMS. 

As of now, it uses a third-party service called tagg.in, which is 
essentially an sms blog. As such, it is extremely limited at the
moment and shouldn't be used.

Also, much of the code is untested and is under heavy development.



=== Build Dependencies ===

smsh currently makes use of the curl library to download files.
Hence, in order to build it, you need to have the curl development
libraries installed. In Debian, it is the libcurl-dev package.

Check the package repository of your distro for the curl development
library package. Or you can always download them from the offcial
curl website. http://curl.haxx.se

Also, make sure you have the build-essential or base-devel packages
installed. These packages are distro-specific and usually contain 
stuff like gcc, make, etc.



=== How to build ===

I added a little makefile just to make things easy. It's still a
crappy makefile, no arguing on that, but it gets things done.
All you need to do is:

	cd source
	make smsh

It should automagically build it.
To do a cleanup, run:

	make clean



=== How smsh works ===

I'll put it simply here. The third party serice, tagg.in maintains
an RSS feed page for every registered user where the texts they send
sit quietly. So the url looks like: http://tagg.in/Rss/user/

What this application does is downloads that page, saves it in the
directory of the executable as ".downloaded_feed", then trims the
whitespaces and saves it in another file as ".feed". These files
remain hidden unless you decide to go and pull down their pants.

Also, at the start of the program, the time at which the program 
starts is recorded in a file called "lastmsg.txt". 

Now, the ".feed" is parsed by the functions in analyze.c. 
It basically first looks for the </image> tag, followed by the <pubDate> 
tag. The </image> tag is searched basically to get to a "starting point" 
so as to avoid similar upcoming tags before it. After that, the <pubDate> 
tag contains the date of the text.

The date is parsed using another function and then compared to the
date stored in lastmsg.txt. If the date in lastmsg.txt is "greater" 
than the one in <pubdate>, then nothing happens, else the date in 
<pubdate> replaces the date in lastmsg.txt.


Once that happens, the parser looks for the <description> tags and 
starts extracting the command. And then it executes it....regardless 
of it being a real command or not.

Really, that's how it rolls. I'll try fixing it in the upcoming days 
maybe. Need to set up error handling for the system() call as well.

Basically, all of that happens in a loop called by main(), which in 
the original was done using recursion. I thought recursion might be a 
bad idea since in practical usage, the program might need to run for 
a long time and as such each recursive call of the function would 
only start taking up space on the stack. I don't know if I'm being 
stupid but I'm alright as long as it works.

Check the FIXES file for a list of stuff I've fixed since the 
original. You can check the original files in the original/
directory.




=== About this fork ===

I use this fork mostly for developing smsh in my own way. I 
routinely plan on sending out required changes to the original 
smsh as long as the original author keeps on accepting and 
maintaining it. My primary reason for maintaining a separate
fork on my own is to use this as grounds for practicing C. 
It's gonna be an absolute bloodshed down here with the program 
breaking more often than actually working. But hey,
that's the fun.

Think of this as my playground. Nothing more, nothing less. 
I just want my playground to be mine, and so I plan to do things
my way here while sending changes back to the original. 

Of course, you're all welcome to play. Just don't step on the 
flowers. Mom isn't quite fond of kids stepping on her flowers >.>





=== Security Concerns ===


Code-wise, it might just be disaster. Code quality is horrible 
at the moment. Lots of crappy string functions and handling.

"Though I walk through the valley of the shadow of string 
and array, I shall fear no buffer overflows."

Basically, that. Also, code has no error-handling at a lot of
places.Besides, as of now, it hardly produces output I want as
I haven't gotten much time to test it out.

Another security issue, an actual one, is that the rss feed page 
in tagg.in isn't exactly password protected so to say. So, anyone 
can just download the xml file through curl and read all the messages. 
GG. I definitely hate this third party dependency. If anyone
makes something like that with no time limits and better protection, 
I'd love you like a lover.



 

=== License ===


I really don't know if I even possess the right to license the 
files in this fork,because it is after all a fork of the original. 
Then again, the original didn't have anything in it so 
I think it's fine. 

And so, like all cute coders out there, I shall license this 
program under the -

GENERAL PUBLIC LICENSE VERSION 3. YUS, IN CAPS.

You can find the license in the COPYING file. If I'm violating
any laws or whatever, let me know before filing a case against 
me or sending me to jail. I hate jail. 



=== Miscellaneous stuff ===

Well, the original author can really use some help with this 
I believe. There hasn't really been any development on it for 
months, so contribute to THAT repository. I'm fine if you send 
your changes here, I'd be more than glad, but hey, this is just
a lousy fork for me to learn, so unless your intentions are 
purely evil, or just not serious enough, send your contributions 
to the main repo. https://github.com/uniquerockrz/smsh





				--- The End ---