Class 11 and 12 quiz

- or --

What symbols come before an option on the command line?

tty device driver

What is the program the collects the characters you type at the command line?

When you hit Enter on a PC or Return on a Mac

When does this program send what you have typed at the command line to the shell?

the list of directories the shell must search to find the file to run a command

What does the PATH shell variable contain?

no, that is the responsibility of the program itself

Does the shell check that a program gets the arguments or options it needs?

./work.sh

If you wanted to run the executable script work.sh in your current directory without using bash, what would you type at the command line?

a running program

What is a process?

it goes into an inactive state called sleep

What does the shell do after it runs the program the user entered at the command line?

it sends an exit status to the shell

What does a program do JUST BEFORE it stops running?

it means that the program encountered no errors

What does an exit status of 0 mean?

The keyboard

By default, where does Standard Input come from?

To the screen

By default, where does Standard Output go?

ls > dir_listing.txt

If you wanted to send the output of ls to the file dir_listing.txt, what would you enter at the command line?

do_something < data.txt

If you wanted the program do_something to take input from the file data.txt what would you write at the command line?

do_something > /dev/null

If you wanted to run the program do_something but have no output appear on the screen, or be sent to a file, what would you type at the command line?

who >> logged_on.txt

If you wanted to add the output of who to the file logged_on.txt what would you type at the command line?

from Standard Input

If a program does not specify where its input comes from, where would it come from?

to Standard Output

If a program does not specify where its output goes to, where would it go?

to Standard Error

Where does a program send its error messages?