Ch 4

Question 1

less

Answer 1

Opens the text file in a pager, which allows for easy reading

Question 2

cat

Answer 2

dumps the contents of the text file on the screen

Question 3

head

Answer 3

Shows the first ten lines of the text file

Question 4

tail

Answer 4

shows the last ten lines of the text file

Question 5

cut

Answer 5

used to filter specific columns or characters from a text file

Question 6

sort

Answer 6

sorts the contents of a text file

Question 7

wc

Answer 7

counts the number of lines, words and characters in a text file

Question 8

^text

Answer 8

Matches line that starts with specified text

Question 9

text$

Answer 9

Matches line that ends with specified text

Question 10

*

Answer 10

wildcard

Question 11

[abc]

Answer 11

matches a, b or c

Question 12

?

Answer 12

Extended regular expression that matches zero or one of the preceding character

Question 13

+

Answer 13

Extended regular expression that matches on or more of the preceding characters

Question 14

*

Answer 14

matches zero to an infinite number of the previous character

Question 15

{2}

Answer 15

matches exactly two of the previous character

Question 16

colou?r

Answer 16

matches zero or one of the previous character

Question 17

(…)

Answer 17

used to group multiple characters so that the regular expression can be applied to the group

Question 18

grep -i

Answer 18

matches upper and lower case letters

Question 19

grep -v

Answer 19

shows only lines that do not contain regular expressions

Question 20

grep -r

Answer 20

seraches files in the current directory and all subdirectories

Question 21

grep -e

Answer 21

searches for lines matching more than one regular expression. Use -e before each regular expression you want to use

Question 22

grep -E

Answer 22

interprets the search pattern as an extended regular expression

Question 23

grep -A <number></number>

Answer 23

shows <number> of lines after the matching regular expression</number>