Chapter 5 OS

Which environment variable contains a list of directories that is searched for commands to execute?

• PATH

• PS1

• EXEC

• PS2

Select the command that can report the location of a command:

• who

• where

• which

• what

A pair of single quotes (') will prevent the shell from interpreting any metacharacter. True or False?

• True

• False

A pair of double quotes (") will prevent the shell from interpreting any metacharacter. True or False?

• False

• True

Using a pair of back quotes (`) will cause a shell to execute the back-quoted text as a command and substitute the output back into the original command. True or False?

• False

• True

The semicolon (;) can be used to separate multiple commands to be executed in order. True or False?

• True

• False

The double ampersand characters (&& ) are used to separate commands to be executed conditionally, where if the command to the left of the ampersands fails, then the command to the right of the ampersands will be executed. True or False?

• False

• True

To be able to output messages to the screen, use the _______ command:

• print

• display

• echo

• type

The _______ command will print a list of the commands that you’ve previously executed.

• history

• eval

• list

• exec

To execute the same command as previously executed five commands ago, you would type:

• • @-5

• • &5

• • !-5

• • !5