Question 1

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

Accepted Answer

The sed command is a stream editor that can perform basic text transformations on an input stream (a file or input from a pipeline). It can indeed be used to remove unwanted lines of text by matching patterns or line numbers.

Question 2

What permissions are required to execute a shell script in a manner similar to any other executable program on the system?

Accepted Answer

To execute a shell script like any other executable program, both read and execute permissions are required. The read permission is necessary for the shell to read the script's contents, and the execute permission allows it to be run as a program.

Question 3

The ability to extract, manipulate, and format text using pattern action statements belongs to which command below?

Accepted Answer

The 'awk' command is used for text processing and is capable of extracting, manipulating, and formatting text using pattern action statements.

Question 4

What number represents the stdin file descriptor?

Accepted Answer

In Unix and Unix-like operating systems, the file descriptor for standard input (stdin) is 0.

Question 5

What character is used to delimit most Linux configuration files?

Accepted Answer

Most Linux configuration files use the colon (:) as a delimiter to separate various elements within the file.

Question 6

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.

Accepted Answer

The command on the left of the && construct is executed first, and the command on the right is executed only if the first command completes successfully.

Question 7

You are limited to using one pipe | metacharacter on the command line to pipe information from one command to another command.

Accepted Answer

You can use multiple pipe | metacharacters in a command line to pass output from one command as input to another command, chaining multiple commands together.

Question 8

Select the escape sequence that is used for a form feed:

Accepted Answer

The escape sequence for a form feed, which advances the paper feed in printers or changes to a new page in documents, is represented by "\f".

Question 9

A list of all exported environment and user-defined variables in a shell can be viewed with what command below?

Accepted Answer

The `env` command is used to display all the exported environment variables in a shell.

Question 10

The standard output and standard error from a terminal screen within the BASH shell can be redirected to a file on the filesystem using what shell metacharacter, followed by the absolute or relative pathname of the file?

Accepted Answer

The shell metacharacter ">" is used to redirect standard output (stdout) and standard error (stderr) from a command in the BASH shell to a file. This redirection can be to either an existing file (overwriting it) or to a new file.

Question 11

Select the metacharacter that can be used to send the standard output of one command to another command as standard input:

Accepted Answer

The pipe symbol (|) is used to take the output of one command and send it as input to another command.

Question 12

What number represents the stderr file descriptor?

Accepted Answer

The stderr file descriptor is represented by the number 2. In Unix and Unix-like operating systems, file descriptor 0 is stdin (standard input), 1 is stdout (standard output), and 2 is stderr (standard error).

Question 13

The default BASH shell prompt is set by an environment variable. What command can be used to view this variable?

Accepted Answer

The default BASH shell prompt is set by the environment variable PS1. To view its value, you can use the command `echo $PS1`.

Question 14

The environment variables that are set by default and their current values can be viewed with what command?

Accepted Answer

The answer of The environment variables that are set by...

Question 15

Which command can be used to count the number lines, words, and characters in a file?

Accepted Answer

The command "wc" stands for word count. It is used to count the number of lines, words, and characters in a file.

Question 16

In order to redirect a file to the standard input of a command, what metacharacter should be used?

Accepted Answer

The "<" metacharacter is used to redirect a file to the standard input of a command.

Question 17

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

Accepted Answer

/etc/profile is executed for all users on the system immediately after login. It sets the initial environment variables for all user sessions, including HOME, PATH, and others.

Question 18

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.

Accepted Answer

To append output to an existing file in the BASH shell, you use two greater-than signs (>>) alongside the file name, not three.

Question 19

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

Accepted Answer

The `tr` command in Unix/Linux is used to translate, squeeze, and/or delete characters from standard input, writing to standard output. It is commonly used for replacing or removing specific characters in its input data set.

Question 20

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

Accepted Answer

Environment files are essentially scripts that can be executed by the shell, so any command that can be executed on the command line can also be placed inside an environment file.

Quiz 7: Working With the Bash Shell