What funtionality comes from Terminal.app and not bash (or other shells)?

Question

I am planning to write an alternative terminal program ( --mostly-- for aesthetics sake) and I want to make sure I cover all of the functionality that I want from Terminal.app in my program. What I'd like to know is what functionality is attributable to the Terminal.app program and not the shell it is using.
Message was edited by: Camden Jared Narzt

Answer 1

You should find the ANSI Terminal Escape Sequence standard, which evolved out of the Digital Equipment Corporation VT100 line of terminals. Getting the escape sequences implemented correctly is the hard task.
Roughly speaking, the Terminal handles displaying the characters from the process(s) and sending keyboard characters (again based on ANSI standard) to the process(s)).
The Terminal also handles text selection, copy and paste.
The Terminal may also send mouse movement and click information (optional).
You could start with an existing terminal emulator, such as the open source project iTerm <http://iterm.sf.net>, or just contribute to the iTerm project.
There are also X11 based terminal emulators such as xterm, rxvt, etc... where the source code is available.
As with all open source code bases, if you start with that code, you are most likely obligated to make your source code available as well, unless you only use the resulting terminal emulator for your own use.
I do NOT know where the official ANSI standard can be found, but this is from the DTTERM Common Desktop Environment man page
<http://www.helsinki.fi/atk/unix/decmanuals/DOC_51/HTML/MAN/MAN5/0200___.HTM>
and will give you a flavor for the kind of stuff you will need to implement.
As for what bash implements, start by reading "man bash", then read man sh, man ksh, man tcsh, man zsh, and you will start to get a favor for what a shell does.
For the most part the terminal displays the text and sends keyboard input. The shell runs programs, and command line editing, command line recall, etc... A lot of the commands that are run by the shell are just separate programs of their own, so they are not part of the shell.
Message was edited by: BobHarris