Unix Tools

Have finished practice sheet 0.

Very preliminary introduction and refresher to UNIX commands.

It's interesting how even if you had never used the command before, you can read it and kind of think what it would do.

like

ls ~/ [shows the contents of the home directory]
ls .. [shows the contents of the directory one level higher]
rm ../wordssomethingelse somefile [removes both the wordssomethingelse file and somefile]
mv ~/somefile . [moves somefile which is in the home directory here (the dot)]
mv words wordssomethingelse [rename the file called words to wordssomethingelse]

Note how you can specify DO THIS AT THIS LOCATION ON THIS AND THIS AND THIS... and you can leave out the location information and put it in as needed.

I imagine that one becomes more and more 'fluent' in the language of the command line. I think the little full stop meaning 'here' is cute too.

Played around with the various shells available (bash, tcsh) and I think I'm happy with bash.

bash has that nice auto-completion feature.

That

THIS=that variable setting feature is nice too.

echo $USER is important to remember for getting environment variables.

We also used
ps [for all running processes in the shell]
set [for checking all the variables]

Ronald Pose

UNIX was designed as an OS for software development. It's very powerful, but it can also be very cryptic.

No sophisticated programming, no theory, just learning how to use the tools for program development on UNIX.
You don't need to memorise everything, just where to find the commands for each tool.

Regular Expressions!!! I'd forgotten all about these.

You have to do the practical exercises in your own time.

ssh ra-clay.cc.monash.edu.au
You can use these machines from home.

Processes and Shells
We want to understand the philosophy of UNIX and how it fundamentally operates.
There are processes, and there are files. Even the mouse and keyboard are, you write / read them in the same way.

How do you glue these together?

We have shells.
The shell is a command interpreter.

ls | grep "txt"

using grep as a filter for the output of ls