Wildcards

Question 1

What is a wildcard?

Answer 1

a character or string used for pattern matching

Question 2

What is globbing?

Answer 2

The expansion of wildcards patterns into a list of files or directories

Question 3

*-

Answer 3

A wildcard for trying to match one or more characters

Question 4

?

Answer 4

a wildcard for matching exactly one charater

Question 5

[]

Answer 5

Matches exactly one character in the brackets []

eg:

ca[nt]
-cat (yes)
-can (yes)
-candy (yes)
-catch (yes)
-cap (no)

Question 6

[!]

Answer 6

Match any one thing in the bracket that is NOT in a file

Question 7

[a-g]*

Answer 7

Match all the characters that are in the range

Question 8

[[:alpha:]]

Answer 8

Matches alphabetical characters (lower and upper)

Question 9

[[:alnum:]]

Answer 9

letters and decimal digits

Question 10

[[:digit:]]

Answer 10

0-9

Question 11

[[:lower:]]

Answer 11

lowercase letters

Question 12

[[:space:]]

Answer 12

Whitespace (tabs, newline, space)

Question 13

[[:upper:]]

Answer 13

uppercase letters

Question 14

How do you match wildcard characters?

Answer 14

Use an \

Question 15

ls *.txt

Answer 15

Lists everything with .txt

Question 16

ls ??

Answer 16

lists all files that are 2 characters long

Question 17

ls a?.txt vs ls a*.txt

Answer 17

One will just ab.txt, the other will list a.txt and ab.txt

Question 18

ls c[aeiou]t

Answer 18

cat and cot

Question 19

ls [a-d]*

Answer 19

lists anything that has at least 1 or more instances of that pattern a-d

Question 20

stdout

Answer 20

Standard output or 1

Question 21

stderr

Answer 21

Standard error or 2

Question 22

stdin

Answer 22

Standard input or 0

Question 23

>

Answer 23

redirects output to a file and overwrites w/e was there

Question 24

> >

Answer 24

redirects output to a file and appends to what was there

Question 25

<

Answer 25

redirects input to a command

Question 26

&

Answer 26

redirects to a file descriptor instead of name

Question 27

2>&1

Answer 27

combines stderr and stdout

Question 28

2>file

Answer 28

redirect a standard error to a file

Question 29

ls -l&raquo_space; files.txt

Answer 29

appends the listed output to files.txt