Linux Essentials 2.0 & 2.21 | Archiving and Compression Module 9 | Chapter 09 Exam Answers Full 100%
Compression of a file works by:
- Storing most of the data on removable media and just leaving a pointer
- Consolidating multiple files into one
- Eliminating gaps within the file
- Removing the high order bit from each byte
- Removing redundant information
In general, for which of the following would you want to use lossless compression?
- An mp3 audio file
- A log file
- A movie
- A JPEG image
- An encrypted email
- Is often used with documents
- Usually results better compression than lossless
- Is often used with images
- Sacrifices some quality
- Decompresses to an identical version as the original
gzip myfile.tar. What happens?
myfile.taris unarchived into the current directory
myfile.tar.gzholds a compressed version of
- An error; you forgot to specify the file with
- An error; you forgot to pass the name of the output file
How would you obtain output similar to the following?
compressed uncompressed ratio uncompressed_nam
278168 1016950 72.6% tags
gunzip –t tags
>gzip –l tags
Which command would you use to archive the
Documentsdirectory and compress it with
tar –cjf Documents
tar –fzc Documents documents.tbz
tar –czf documents.tbz
tar –cf Documents documents.tbz
tar –cjf documents.tbz Documents
Which flag would you pass to
tarin order to have it make a new archive?
Which command will show what is inside the compressed tarball with a name of
tar –tzf foo.tar.gz
tar –tf foo.tar.gz
tar –tjf foo.tar.gz
tar –lf foo.tar.gz
tar –xf foo.tar.gz
In the command
tar-cvjf foo.tbz a b c, what are
- Matching operators; anything starting with a, b, or c will be added
- Nothing; –
cvjfonly expects one parameter
- Extra flags passed to tar
- File names to be added to the archive
- a is the directory that will be prepended to files; b and c are files inside it
Given the command
tar –cvjf homedirs.tbz /home, which of the following are true?
/homedirectory will be restored with the contents of
- The output file will be compressed
- Only files starting with
/homewill be extracted from the archive
- Files that are present in the archive might overwrite files in
- The command will print out each filename as it is processed
You archived your users’ directories into a file called
backup.tar.gz.You then view the archive and see the filenames follow this convention:
How will you extract just the files for the user called fred?
tar –tjf backup.tar.gz /home/fred
tar –xjf backup.tar.gz home/fred/
tar –tzf /home/fred < backup.tar.gz
tar –xzf backup.tar.gz fred
tar –xzf backup.tar.gz home/fred/
Which of the following commands will create a zipfile with the contents of your
zip –c mydocs.zip Documents
zip mydocs.zip Documents
zip –f mydocs.zip Documents
zip -cf mydocs.zip Documents
zip -r mydocs.zip Documents
Given a file called
documents.zip, how can you see what’s in it without extracting the files?
unzip -l documents.zip
zip -lf documents.zip
unzip --list documents.zip
zip -l documents.zip
Given a file called
documents.zip, how can you extract just the files under ProjectX?
unzip documents.zip Project
unzip documents.zip ProjectX/*
zip -x documents.zip ProjectX
unzip documents.zip | grep ProjectX
unzip -t documents.zip ProjectX
You try to compress a file that is already compressed. Which of the following statements is true?
- The file will actually be uncompressed
- The compression algorithm needs to be set to the “currently compressed” mode for it to be compressed further
- The file will not be compressed any further than it already was
- The file changed while you were compressing it
- The file will be deleted
Which of the following commands can be used to compress a file?
The three main modes of
In the command
tar -czf foo.tar.gz bar, what is the purpose of the
- Tells tar to copy only files, and not directories
- Tells tar to write to the file that follows the flag
- Tells tar to read from the file that follows the flag
- Tells tar to print the name of each file as it is processed
- Specifies extra compression is to be used
Which two commands do the same thing?
tar -czf foo.tar.gz foo
tar -c foo | gzip > foo.tar.gz
tar -x foo | gzip
tar -tzf foo.tar.gz
tar -xzf foo.tar.gz
Which two programs use the Lempel-Ziv-Markov chain algorithm?
By default, the
zipcommand replaces uncompressed files with compressed files.
True or False?
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