Ch.6 Redirection

Question 1

What does I/O stand for

Answer 1

Input/output

Question 2

What does I/P redirection allow us to do?

Answer 2

Redirect the input and output of commands to and from files, as well as connect multiple commands together

Question 3

What does cat do

Answer 3

Concatenate files

Question 4

what does sort do?

Answer 4

Sort lines of text

Question 5

what does uniq do?

Answer 5

Report or omit repeated lines

Question 6

What does grep do

Answer 6

Print lines matching a pattern

Question 7

what does wc do?

Answer 7

Print newline, word, and byte counts for each file

Question 8

what does head do?

Answer 8

Output the first part of a file

Question 9

what does tail do

Answer 9

Output the last part of a file

Question 10

What does tee do?

Answer 10

Read from standard input and write to standard output and files

Question 11

What are the two types of output?

Answer 11

1. The program’s results (the data the program is designed to produce) 2. Status and error messages that tell us how the program is getting along.

Question 12

What is expressed as stdout?

Answer 12

standard output

Question 13

What is expressed as stderr?

Answer 13

standard error

Question 14

What are linked by default to the screen and not saved into a disk file?

Answer 14

Standard Error and Standard Output

Question 15

What is expressed as stdin?

Answer 15

standard input

Question 16

What is by default attached to the keyboard?

Answer 16

standard input

Question 17

What key is the redirection operator

Answer 17

>

Question 18

What will truncate an existing file or create a new, empty file?

Answer 18

Simply using the redirection operator with no command preceding it. i.e. > ls-output.txt

Question 19

What does the shell reference internally as file descriptors 0,1,2?

Answer 19

Standard input, output, and error, respectively

Question 20

What redirection must refer to its file descriptor?

Answer 20

Standard Error

Question 21

How do you dispose of unwanted output?

Answer 21

/dev/null

Question 22

What does conatenating files do?

Answer 22

the command reads one or more files and copies them to standard output.

Question 23

What happens if cat is not given any arguments?

Answer 23

It reads from standard output. (It’s waiting for you to type something)

Question 24

How do you tell cat it has reached EOF?

Answer 24

Ctrl-D

Question 25

What does EOF mean

Answer 25

End of File

Question 26

What does the shell feature called pipelines utilize?

Answer 26

Thee capability of commands to read data from standard input and send to standard output.

Question 27

What key is the pipe operator?

Answer 27

|

Question 28

what is piping?

Answer 28

The standard output of one command can be chained into the standard input of another

Question 29

What is the difference between the pipeline operator and the redirection operator?

Answer 29

the redirection operator connects a command with a file, while the pipeline operator connects the output of one command with the input of a second command.

Question 30

What command prints the first ten lines of a file?

Answer 30

Head

Question 31

What command prints the last ten lines of a file?

Answer 31

tail

Question 32

How do you adjust commands that print the first/last ten lines of text of a file?

Answer 32

-n