update ABOUT.md

[sjwarner-bp]

Fixes #152

I'm open to suggestions for this, as I wasn't too sure what to write. Let me know if you think I've missed out any important points @exercism/bash

[budmc29]

It's a very good start.

I think it would be better to focus on describing the language more than telling the users why they should use it.
Most users that start using bash or shell know what they are getting into anyway.

Looking at other description documents, they follow a similar pattern:

• Short introduction, definition style
• Origins/Creator
• Usage and more infoh

That seems like a good pattern for us as well.

---

From the creator's website https://tiswww.case.edu/php/chet/bash/bashtop.html and https://tiswww.case.edu/php/chet/bash/FAQ:

Bash is a Unix command interpreter (shell). It is an implementation of
the Posix 1003.2 shell standard, and resembles the Korn and System V
shells.

Bash contains a number of enhancements over those shells, both
for interactive use and shell programming. Features geared
toward interactive use include command line editing, command
history, job control, aliases, and prompt expansion. Programming
features include additional variable expansions, shell
arithmetic, and a number of variables and options to control
shell behavior.

Bash was originally written by Brian Fox of the Free Software
Foundation. The current developer and maintainer is Chet Ramey
of Case Western Reserve University.

From the GNU's page https://www.gnu.org/software/bash/:

Bash is the GNU Project's shell. Bash is the Bourne Again SHell. Bash is an sh-compatible shell that incorporates useful features from the Korn shell (ksh) and C shell (csh). It is intended to conform to the IEEE POSIX P1003.2/ISO 9945.2 Shell and Tools standard. It offers functional improvements over sh for both programming and interactive use. In addition, most sh scripts can be run by Bash without modification.

The improvements offered by Bash include:

Command line editing
Unlimited size command history
Job Control
Shell Functions and Aliases
Indexed arrays of unlimited size
Integer arithmetic in any base from two to sixty-four

Origin of name:

The shell's name is an acronym for Bourne-again shell, punning on the name of the Bourne shell that it replaces and on the term "born again".

Wiki description (why not?):

Bash is a command processor that typically runs in a text window, where the user types commands that cause actions. Bash can also read and execute commands from a file, called a script. Like all Unix shells, it supports filename globbing (wildcard matching), piping, here documents, command substitution, variables, and control structures for condition-testing and iteration. The keywords, syntax and other basic features of the language are all copied from sh. Other features, e.g., history, are copied from csh and ksh. Bash is a POSIX-compliant shell, but with a number of extensions.

[sjwarner-bp]

I'll look to condense these into the description.

Some snippets above seem almost excessive in detail, and we should look to keep this intro somewhat concise - I'll update my PR this evening hopefully with the changes 🙂

[budmc29]

@kotp what do you think?

[kotp]

Looking forward to what @sjwarner-bp comes up with. Should we mention how to get help on bash in the terminal? Such as info bash or man bash to show folks how to get help on the built-ins.

I don't believe the mention of ls is warranted, as that is not a bash command. It is an external to bash tool. It is mentioned in the Bash manual, but not until talking about redirection.

[budmc29]

Any updates on this?

[sjwarner-bp]

Been a bit ill recently - I'll get back on this as soon as! Wanted to make sure that it is done well 😉

[sjwarner-bp]

I've added in a handful of the suggestions above. Let me know if you think I've missed any of the important bits (some of the paragraphs mentioned above had quite a bit of overlap).

[kotp]

Let's have one sentence per line, as agreed to on exercism/meta/#84

[kotp]

There is no other mention of a "command processor", but "command interpreter" is the term used in the citation, and further used in the rest of the content.

[budmc29]

Needs two spaces for new line.

[budmc29]

Is _cite valid markdown syntax?

[sjwarner-bp]

Oops! Forgot the closing _ - I wanted it to be italicised.

I'll fix these tonight 🙂

[budmc29]

Looks good, thank you.