Workbook 5

Question 1

What are the three structures associated with every Linux file?

Answer 1

Dentry, Inode, Data. [5/6]

Question 2

What pieces of metadata are found in an inode?

Answer 2

The files metadata. [5/5]

Question 3

What is a dentry?

Answer 3

The filename. [5/5]

Question 4

What character abbreviation does the ls command use to identify (i) a regular file, (ii) a symbolic link, (iii) a directory, (iv) a block device node, (v) a character device node?

Answer 4

Regular Files: - (dash)
Symbolic Link: l (lowercase L)
Directory: d (lowercase D)
Block Device Node: b (lowercase B)
Character Device Node: c (lowercase C) [5/6]

Question 5

What three timestamps are stored in an inode?

Answer 5

atime: Updates whenever the file’s data is read.
ctime: Updates whenever the file’s inode information changes.
mtime: Updates whenever the file’s data changes. [5/8]

Question 6

When does a file’s atime change?

Answer 6

Updates whenever the file’s data is read. [5/8]

Question 7

What is the difference between a file’s ctime and mtime?

Answer 7

ctime updates whenever the file’s data is read.

mtime updates whenever the file’s data changes. [5/8]

Question 8

Where is a file’s creation time stored in Linux?

Answer 8

Linux doesn’t store an initial point of creation time for files. [5/8]

Question 9

What is the difference between a file’s size and its length?

Answer 9

Length is how large the file is in bytes.

Size is the amount of disk space the file consumes. [5/8]

Question 10

What two commands display the metadata stored in an inode?

Answer 10

ls and stat [5/9]

Question 11

What is the difference between the –r and the –R options of the ls command?

Answer 11

• r (lower case): Reverses the sorting order.

- R (upper case): Lists the subdirectories as well. [5/10]

Question 12

Write a command line that outputs /etc’s contents in order of modification time.

Answer 12

ls /etc -t [5/10]

Question 13

What does the ls command’s –h and –F options do?

Answer 13

• h: “Human Readable” mode uses abbreviations when reporting file lengths.
• F: Decorates filenames with symbols to indicate file type. [5/10]

Question 14

Using an ls command option, give a command line that outputs the inode of /etc’s files.

Answer 14

ls /etc -i [5/10]

Question 15

What is a hard link and why would you create one?

Answer 15

Multiple Dentries are assigned to a single inode as you can exist in two places or have two names. [5/17]

Question 16

What is a soft (a.k.a. symbolic) link?

Answer 16

Distinct inodes that refer to other files. [5/17]

Question 17

What does a soft link contain?

Answer 17

A reference to another file to link to.[5/20]

Question 18

What happens if you only provide 1 argument to the ln command?

Answer 18

the ln command will effectively assume

a last argument of “.”. [5/21]

Question 19

How can you create a recursive link?

Answer 19

Having two or more links, that all link to each other. [5/22]

Question 20

When is a hard link appropriate and when is a soft link appropriate?

Answer 20

Soft links can refer to directories while Hard links cannot. More reasons on [5/23]

Question 21

How do the locate and find commands operate differently?

Answer 21

The locate command uses a database to quickly locate files on the system by filename.
The find command performs a real time, recursive search of the filesystem. [5/55]

Question 22

Using the locate command, give a command line that lists all .gif files on the system that have fish in their name.

Answer 22

locate “fish.gif” [5/56]

Question 23

What does the following command line do? find /etc/sysconfig/networking

Answer 23

Prints out all files that have /etc/sysconfig/networking in their path. [5/56]

Question 24

Give a command line to find all .conf files in /etc

Answer 24

locate /etc/”*.conf” [5/56]

Question 25

Give a command line to find all files in /etc owned by group cist

Answer 25

find /etc/ -group cist [5/57]

Question 26

Give a command line to find all files in /etc last modified 3 days ago

Answer 26

find /etc/ -mtime 3 [5/57]

Question 27

Give a command line to find all files in /etc modified less than 3 days ago

Answer 27

find /etc/ -mtime -3 [5/57]

Question 28

Give a command line to find all files in /etc that are more than 300K in size

Answer 28

find /etc/ -size +300 [5/57]

Question 29

Give a command line to find all files in /etc owned by user george

Answer 29

find /etc/ -name george [5/57]

Question 30

Give a command line to find all files in /etc that are symbolic links

Answer 30

find /etc/ -type l [5/57]

Question 31

Using find and find actions, give a command line that finds all files in /etc that are greater than 200K in size and copies them to /tmp/big/

Answer 31

find /etc -size +200k -exec cp {} /tmp/big \; [5/58]

Question 32

What option must you almost always use with the tar command?

Answer 32

-f which specifies which archive file is being created, extracted, or listed. [5/69]

Question 33

Using tar, give the command line that archives a directory named report and that names the archive report.tar

Answer 33

tar cf report.tar report [5/69]

Question 34

Give a command line that lists the contents of the archive named report.tar

Answer 34

tar tf report.tar [5/69]

Question 35

Give a command line that extracts the contents of the archive named report.tar

Answer 35

tar xf report.tar [5/69]

Question 36

What does the tar command’s –v option do?

Answer 36

Activates verbose mode, listing each and every file it’s currently interacting with [5/71]

Question 37

Do you have to precede the tar command’s options with a dash?

Answer 37

No. [5/73]

Question 38

What does it mean if a file has a .tar.gz extension?

Answer 38

The archive was compressed using the gzip compression format [5/73]