UNIX for Dummies Questions & Answers

Hey you guys,

There's a couple questions I cannot find the answers to anywhere in this book for my Operating Systems class, hopefully you guys could help. I believe we are in the Bourne shell.


1. Match each description to the appropriate type of variable

Used in shell programs

Also called personal variables

Also called standard shell variables

Always completely capitalized


A. Environment variables
B. User-created variables
C. Positional parameters

2. Which of the following is the appropriate command to change the value of the environment variable PATH so it retains everything that was in it before, but so that it will have /scripts appended to the end of it?

PATH=$PATH:/scripts
$PATH=PATH:/scripts
PATH=$PATH + /scripts
$PATH=PATH + /scripts


3. You wish to run a script named myscript which is located in the directory /scripts. The directory is NOT contained in the PATH environment variable's value, nor do you wish to make it so. In order to execute the script, you could type the following on the command line:
___________ /scripts/myscript

Hi,

These would be my answers:

1.-
Used in shell programs -> Positional parameters
Also called personal variables -> User-created variables
Also called standard shell variables
Always completely capitalized -> Environment variables

2.-
PATH=$PATH:/scripts

3.-
sh /scripts/myscript

But not sure.

Regards,
Birei

sh not bash.

I think the capitalization is traditional, might even be a recommended style, like "capitalize anything exported and not, not". In this usually case sensitive world, to hit old ones (PATH, HOME, SHELL, etc.) you must capitalize, but new ones can come into existence that are not capitalized. export makes not discriminate. The ones recognized by the kernel are probably all capitalized! It is good to know which names have extra magic.

Well, when it comes to the capitalization, would you recommend something outside or what Birei suggested (within the answers allowed, obviously)?

Thanks for the quick responses though!

In school, the professor sets the right answer and reality is suspended. You knew that!

Make sure you say sh for Bourne not bash, unless the prof says bash stand for Bourne Shell.

I will, thank you.

One more question for ya, with my Mac, I can't open the Unix file that she'd allow to download if I had a PC so I can't figure these out. I tried in terminal, but I don't trust it. The only one I got to work was Kabul.


select all the words listed below which look recognizes as valid.

Serendipitous
Kabul
Obama
Ichthiology

what UNIX files were these? And what is a "UNIX file", anyway? An archive you don't know how to extract, or a script you're having trouble running? OSX uses BASH too. In what way are they not behaving? If by "unix file" you mean "shell script", shell scripts work in nothing but terminal in OSX. You can't double-click them.