Section 7 - Searching and Extracting Data from Files

Question 1

What is a command line pipe?

Answer 1

The output of the first command is used as input for the second command

Question 2

What is the benefit of using pipes?

Answer 2

Pipes allow for quick execution of commands performing complex tasks

Question 3

What is the grep command?

Answer 3

The grep command searches for keywords in the output

Question 4

What is input and output redirection?

Question 5

How can a program’s output be used as an input?

Answer 5

via the process of piping

Question 6

What is the Xargs command?

Answer 6

Enables a user to generate command line options from files or other programs’ output

Question 7

what does > do?

Answer 7

creates a new file containing standard output ( can overwrite file)

Question 8

> >

Answer 8

appends standard output ot an existing file ( not overwrite it)

Question 9

2>

Answer 9

New file with any standard errors the program with throw

Question 10

2»

Answer 10

to append errors to existing file

Question 11

&>

Answer 11

creates new file with standard error and standard output (overwrites)

Question 12

<

Answer 12

sends content to specified file as input back into standard input.

Question 13

What is normally standard input?

Answer 13

Keyboard is the usual standard input

Question 14

«

Answer 14

accepts text on following lines as standard input

Question 15

<>

Answer 15

specified file used both for standard input and output ( can read and write the file)

Question 16

What is standard output?

Answer 16

Normal program messages

Question 17

Standard Error messages are?

Answer 17

Any error messages