Hoofdstuk 7

Question 1

Compression on a file works by: -7.1

Answer 1

Making the files smaller by removing redundant information

Question 2

Lossy compression: - 7.3

Answer 2

Usually results better compression than lossless
Is often used with images
Sacrifices some quality

Question 3

You type gzip myfile.tar. What happens? 7.3

Answer 3

myfile. tar is removed

myfile. tar.gz holds a compressed version of myfile.tar

Question 4

Which command would you use to archive the Documents directory and compress it with bzip2 compression? - 7.4

Answer 4

tar cjf documents.tbz

Documents

Question 5

In the command tar cvjf foo.tbz a b c, what are a, b, and c? -7.4

Answer 5

file names to be added to the archive

Question 6

Given the command tar cvjf homedirs.tbz /home, which of the following are true? -7.4

Answer 6

The command will print out each filename as it is processed

The output file will be compressed

Question 7

You archived your users directories into a file called backup.tar.gz. You then view the archive and see the filenames follow this convention: - 7.4

Answer 7

home/username/somefile

Question 8

How will you extract just the files for the user called fred?

Answer 8

tar xzf backup.tar.gz home/fred/

Question 9

Which of the following commands can be used to compress a file?

Answer 9

gzip
bzip2
zip

Question 10

Which two commands do the same thing? -7.4

Answer 10

tar c foo | gzip > foo.tar.gz

tar czf foo.tar.gz foo

Question 11

How would you obtain output similar to the following?
compressed uncompressed ratio uncompressed_name
278168 1016950 72.6% tags - 7.3

Answer 11

gzip l tags

Question 12

Which flag would you pass to tar in order to have it make a new archive? -7.4

Answer 12

-c

Question 13

Which of the following commands will create a zipfile with the contents of your Documents directory? -7.5

Answer 13

zip -r mydocs.zip Documents

Question 14

You try to compress a file that is already compressed. Which of the following statements is true? - 7.3

Answer 14

The file will not be compressed any further than it already was

Question 15

The _____ command is normally executed daily to update the database of all files that are on the system. - 7.1

Answer 15

updatedb

Question 16

Which command will show whats inside the compressed tarball with a name of foo.tar.gz?

Answer 16

tar -tzf foo.tar.gz

Question 17

Given a file called documents.zip, how can you extract just the files under ProjectX? - 7.5

Answer 17

unzip documents.zip ProjectX/*

Question 18

In the command tar czf foo.tar.gz bar, what is the purpose of the f flag? -7.4

Answer 18

Tells tar to expect a file name as the next argument