04 Manipulating Files and Directories

Question 1

What does the wildcard * match?

Answer 1

Any characters

Question 2

What does the wildcard ? match?

Answer 2

Any single character

Question 3

What does the wildcard [characters] match?

Answer 3

Any characters of the set [characters]

Question 4

What does the wildcard [!characters] match?

Answer 4

Any characters that don’t belong to the set [characters]

Question 5

What does the wildcard [[:class:]] match?

Answer 5

Any characters that belong to the specified class

Question 6

What does the special class [:alnum:] match?

Answer 6

Any alphanumeric characters

Question 7

What does the special class [:alpha:] match?

Answer 7

Any alphabetic characters

Question 8

What does the special class [:digit:] match?

Answer 8

Any number

Question 9

What does the special class [:lower:] match?

Answer 9

Any lower-case characters

Question 10

What does the special class [:upper:] match?

Answer 10

Any uppercase characters

Question 11

Which files would the wildcard * match?

Answer 11

All files

Question 12

Which files would the wildcard g* match?

Answer 12

Any files that begin with “g”

Question 13

Which files would the wildcard b*.txt match?

Answer 13

Any files that begin with “b” and end with “.txt”

Question 14

Which files would the wildcard Data??? match?

Answer 14

Any files beginning with “Data” followed by exactly 3 characters

Question 15

Which files would the wildcard [abc]* match

Answer 15

Any files that begin with the lower-case letters “a”, “b”, or “c”

Question 16

Which files would the wildcard BACKUP.[0-9][0-9][0-9] match?

Answer 16

Any files beginning with “BACKUP.” followed by exactly 3 numerals

Question 17

Which files would the wildcard [[:upper:]]* match?

Answer 17

Any files beginning with an upper-case letter

Question 18

Which files would the wildcard [![:digit:]]* match?

Answer 18

Any file not beginning with a numeral

Question 19

Which files would the wildcard *[[:lower:]123]

Answer 19

Any file ending with a lower-case letter or a “1”,”2”,or”3”

Question 20

How many directories can you create using a single instance of the mkdir command?

Answer 20

You can make multiple directories using mkdir in a single instance…mkdir dir1 dir2 dir3…etc

Question 21

What would be the result of the following command:

cp item1 item2

Answer 21

File or directory Item1 would be copied to file or directory item2

Question 22

What would be the result of the following command:

cp item1… dir1

Answer 22

File item1 would be copied into dir1

Question 23

Describe the use of the following cp options:

-a / –archive

Answer 23

Copy files/dirs with their existing attributes, instead of the attributes of the user performing the copy

Question 24

Describe the use of the following cp options:

-i / –interactve

Answer 24

Prompt for confirmation before copying (and possibly overwriting) the destination item.

Question 25

Describe the use of the following cp options:

-r / –recursive

Answer 25

Recursively copy (go into each subdirectory and copy) the directory contents

Question 26

Describe the use of the following cp options:

-u / –update

Answer 26

Only copy items that are new or have changed.

Question 27

Describe the use of the following cp options:

-v / –verbose

Answer 27

Display informative messages as copy progresses

Question 28

Describe the use of the mv command

Answer 28

Moves or renames files

Question 29

Describe the use of the following mv options:

-i / –interactive

Answer 29

Prompt for confirmation before moving/renaming (and possibly overwriting) the destination item.

Question 30

Describe the use of the following mv options:

-u / –update

Answer 30

When moving files from one directory to another, only move the files that don’t exist or are newer than existing corresponding files

Question 31

Describe the use of the following mv options:

-v / –verbose

Answer 31

Display informative messages as move progresses

Question 32

Describe the use of the rm command

Answer 32

Remove (delete) files or directories

Question 33

Describe the use of the following rm options:

-i / –interactive

Answer 33

Prompt for confirmation before deleting a file

Question 34

Describe the use of the following rm options:

-r / –recursive

Answer 34

If a directory being deleted has subdirectories, remove them, too. This option must be specified in order to delete a directory

Question 35

Describe the use of the following rm options:

-f / –force

Answer 35

Don’t prompt when deleting files, ignore non-existent files

Question 36

Describe the use of the following rm options:

-v / –verbose

Answer 36

Display informative messages as the deletion is performed.

Question 37

What are two restrictions to keep in mind when creating hard links?

Answer 37

1. Hard link cannot refer to file on another filesystem

2. Hard links cannot refer to a directory

Question 38

True or False: every file has a single hard link that gives that file its name

Answer 38

True

Question 39

True or False: a hard link is completely indistinguishable from the referenced file itself

Answer 39

True. Hard links have no special indicators of their link

Question 40

True or False: if a hard link is deleted, the file that it links to is also deleted

Answer 40

False

Question 41

How do you create a hard link to a file?

Answer 41

ln file link

Question 42

True or False: a symlink can represent a file or a directory

Answer 42

True. Hardlinks can only reference files

Question 43

True or False: a symlink is a text pointer to a referenced file or directory

Answer 43

True

Question 44

True or False: if a symlink is deleted, only the link is removed; the original file remains intact

Answer 44

True

Question 45

What is the term for the situation that occurs when a file is symlinked and the original file is deleted

Answer 45

a “broken” link

Question 46

How would you determine if an item is hard linked?

Answer 46

Hardlinks are indistinguishable from originals. You would need to compare the inodes of the two files to see if they referenced the same “portion” of the disk. You could do that by ls -li

Question 47

How would you create a symlink to the file foo.txt?

Answer 47

Go to location where you wish to create the symlink and create it relative to the original. For example, if the symlink is to be created in directory ‘baz’ and the original is in the parent directory:

pwd
baz
ln -s ../foo.txt bar.txt