The Anthias Terminal - Recently Updated Pages

Communication Protocol

harshad.rj — Sun, 25 Nov 2007 09:00:53 CST

After considering several alternative communication protocols, simple network sockets were chosen for the communication layer, since

they can be used for local as well as remote sessions, and
can be tunneled through SSH.

The details of the protocol are described below.

Startup

User requests a new session from Anthias and specifies if it is a local session, or a remote session.

Local session

If local session, then

Anthias opens a pseudo-tty,
sets TERM_EXTENDED=AnthiasLocal
starts user's login shell in it.

Remote session

If remote session,

Anthias prompts user to enter remote hostname/ip.
Anthias connects to remote host using SSH.
Anthias sets env-variables:
1. TERM_EXTENDED=AnthiasRemote
2. ANTHIAS_REMOTE_ADDR=#ip_address

(This is required so that remote application can bind to the same ip-address as the SSH session.)

Anthias opens a SSH channel and executes the user's shell in it.

Shell startup

At this point, the user is presented with an innocuous xterm-like interface. There are no special widgets, no directory browsing, nothing. But now, if the user (or the login process) starts an Anthias-capable shell, the ball starts rolling. We will call this hypothetical shell, the AShell.

AShell Registeration

AShell checks if TERM_EXTENDED is set.

AShell creates a socket. If TERM_EXTENDED is AnthiasRemote, then it binds the socket to ANTHIAS_REMOTE_ADDR. Otherwise it binds to localhost.

AShell emits "ANTHIAS_REGISTER_SEQUENCE #my_ip #my_port_num" onto the terminal.

When Anthias sees the ANTHIAS_REGISTER_SEQUENCE, it creates a socket and connects it to the AShell's socket. If the session is local, then this is

straight forward. If it is remote, then the SSH service is used to port-forward.

Anthias emits "ANTHIAS_REGISTER_RESPONSE [success|failure]" onto the terminal.

From now on, communication between AShell and Anthias takes place over the socket.

Communication basics

Communication between AShell and Anthias will be in binary. The advantages of this approach are,

It will save extraneous string parsing and comparisons.
It will save bandwidth, memory, and ultimately, processing time.
Skipping to next message can be efficiently done by skipping a known number of bytes.

Message Types

Here we list the message types used by Anthias to communicate with AShell.

AShell initiated messages

FirstTokenCompletions
ChangePWD

Anthias initiated messages

Version
ExecuteCommand

Project Plans

harshad.rj — Sun, 25 Nov 2007 08:30:55 CST

Mockups

A series of mockups is planned, before actual development begins. The current mockup version is 4.

Upcoming planned releases

Version 5

Syntax Highlighting. One command for now:

cd /name/name/nam

Command parsing by shell. Only the cd command for now.

Version 6

Basic job handling support
Ability to pipe stdout/stdin

Version 7

Clickable links generatd by shell
Image previews

Version 8
SSH session support

Home

pharaoh — Thu, 20 Jul 2006 13:42:21 CDT

Welcome to the Anthias Terminal wiki!

This is a helper site to the sourceforge hosted site. For ease of use, this site is divided into two sections:

Users

Developers

For users, here is a quick link of topics:

Executing

pharaoh — Thu, 20 Jul 2006 13:37:02 CDT

First follow the compilation instructions. Then execute anthias like any other KDE4 program. Note: Use a separte account (say kdetester) for playing with KDE4 programs.

Startup anthias as follows,

> LD_LIBRARY_PATH=$KDEDIR/lib:$QTDIR/lib nice dbus-launch ./anthias_mockup_4

Then inside the anthias terminal, run the demoShell as follows,

> demoShell/demoShell

Compiling

pharaoh — Thu, 20 Jul 2006 13:34:35 CDT

Requirements

QT 4.2 (qt-copy from kde-svn)
KDE 4.0 (from kde-svn)

Compiling

Ensure that QTDIR is set to the path where QT4 is installed. Also, KDEDIR
should be set to where KDE4 is installed. Then,

> $QTDIR/qmake
> make

Now compile the demoShell.

> cd demoShell
> make

Next, read how to execute anthias.

Similar projects

pharaoh — Thu, 20 Jul 2006 10:30:05 CDT

There are a zillion alternative file managers out there, each with different features sets. But none have integrated support for a terminal which can allow the user to work with the traditional console shells and applications.

Here is a list of related projects, in no particular order,

Krusader
OneFinger
Gsh
XmlTerm. This project was hosted on sourceforge earlier. It came quite close to Anthias' goals. But the project seems to be defunct now.

Developers

pharaoh — Thu, 20 Jul 2006 10:05:17 CDT

This page and its sub-pages are intended for developers. Currently work is progressing on the communication protocol.

If you are interested in joinging the project or tracking it, have a look at the plans.

Users

pharaoh — Thu, 20 Jul 2006 10:00:15 CDT

This page and its subpages are for the users of anthias.

FirstTokenCompletions

pharaoh — Mon, 26 Jun 2006 08:42:51 CDT

This message lists all the completions possible for the first token in the command widget. The idea behind this is to reduce the bandwidth by caching the information at the Anthias end.

The message can be sent multiple times, whenever an update is required. Anthias clears its previous cache whenever this message appears.

Format

uint16 : number of categories
for each category

char[ ] : category name or description
uint16 : syntax highlighting code
uint32 : number of entries
for each entry

char[ ] : short name
char[ ] : description