Chapter 7

Which environment file is always executed immediately after login for all users on the system, and sets most environment variables, such as HOME and PATH?

/etc/profile

The file descriptor stdin is represented by the number____.

0

You can redirect a file to the standard input of a command using which metacharacter?

<

You can use the BASH shell to redirect standard output and standard error from the terminal screen to a file on the filesystem using which shell metacharacter followed by the absolute or relative pathname of the file?

>

Users can create their own custom variables, called shell variables.

False

When performing a pipe, do you need to have spaces around the | metacharacter?

False

When redirecting both standard output and standard error to a file, does using the same filename for both result in a loss of data?

False

Aliases are shortcuts to commands stored in special variables that can be created and viewed using the alias command.

True

Any command that can be executed on the command line can also be placed inside any environment file.

True

Are both standard output and standard error displayed on the terminal screen by default?

True

The BASH shell assumes stdout in the absence of a numeric file descriptor

True

The ENV environment variable represents the location of the BASH run-time configuration file.

True

The file descriptor stderr is represented by the number 2.

True

You can use the sed command to remove unwanted lines of text.

True

Which test statement would be used to determine if A is numerically greater than B?

[ A -gt B ]

Which escape sequence represents a form feed?

\f

Which command can be used to extract, manipulate, and format text using pattern-action statements?

awk

Most configuration files on Linux systems are delimited using which characters?

colon

Constructs that alter the ow of a program based on whether a command in the program completed successfully or based on a decision that the user makes given a question posed by the program.

decision construct

Which command could be used to view the contents of the environment variable that represents the BASH shell prompt?

echo $PS1

To see a list of all exported environment and user defined variables in the shell, you can use which command?

env

Shell variables that are typically set by the system and contain information that the system and programs access regularly.

environment variables

Labels representing command input and output

file descriptors

The first line in a shell script, which specifies the pathname to the shell that interprets the contents of the shell script.

hashpling

If you have which permission to a shell script, you can execute the shell script like any other executable program on the system?

read and execute

To see a list of the environment variables and their current values on a system, you can use which command?

set

Files that are typically used to create custom programs that perform administrative tasks on Linux systems

shell scripts

The information that is processed by the command during execution.

stdin

The normal output of a command

stdout

A filter command that takes information from standard input and sends that information to a file, as well as to standard output.

tee

Which command can be used to replace characters in a file sent via Standard Input?

tr

Which command counts the number of lines, words, and characters in a file?

wc

You can send the standard output of one command to another command as standard input using which shell metacharacter?

|

Can the redirection shell metacharacter be used to redirect between a command and another command?

False

Can you combine redirection and piping together?

False

Given the syntax command && command, the command on the left of the && construct is executed only if the command on the right of the && construct completed successfully

False

In a decision construct, you can have an unlimited number of if then statements.

False

To prevent a file from being cleared by the BASH shell and append output to the existing output, you can specify three > metacharacters alongside the file descriptor.

False

Any error messages generated by a command

STDERR