CODE EXAMPLE FOR SHELL

tar gzip compression level

# create
tar -czvf projects.tar.gz projects/
# create with best compression level
# without '-z' becouse of the use of '-I'
tar -I 'gzip -9' -cvf projects.tar.gz projects/
# extract
tar -xzvf projects.tar.gz

-c, --create
      create a new archive
-I, --use-compress-program PROG
      filter through PROG (must accept -d)
-x, --extract, --get
      extract files from an archive
-z, --gzip, --gunzip --ungzip
-v, --verbose
      verbosely list files processed
-f, --file ARCHIVE
      use archive file or device ARCHIVE

tar [-] A --catenate --concatenate | c --create | d --diff --compare | --delete | r --append | t --list |
    --test-label | u --update | x --extract --get [options] [pathname ...]