File archiving and transferring

File archiving

tar is the de-facto standard tool for saving many files or directories into a single archive file. Archive files may have extenssions .tar, .tar.gz etc depending on compression.

# create tar archive gzipped on the way
tar -caf arhive_name.tar.gz directory_to_be_archived/

# extract files
tar -xaf archive_name.tar.gz -C path/to/directory

Other command line options: r - append files to the end of an archive, t - list archive content. f is for the filename, and a selects the compression method based on the archive file suffix (in this example gzip, due to the .gz suffix. Without compression files/directories are simply packed as is.

# xz has better compression ratio than gzip, but is very slow
tar -caf archive_file.tar.xz dir1/ dir2/

Individual files can be compressed directly, e.g. with gzip:

# file.gz is created, file is removed in the process.
gzip file
# Uncompress
gunzip file.gz

Transferring files (+archiving on the fly)

As an Aalto user you may use remote directories [1]. Here we cover general use case, transferring from the command line.

For transferring single files or directories there is scp, though for FTP like functionality there is SFTP.

# transferring a file from the remote server to the current directory
sftp .

# transferring files from your workstation to  remote server
sftp path/to/file_to_copy

Another use case, making a directory backup with rsync:

# sync two directories
rsync -vauW path/to/dir1/

(*) Transferring and archiving your data on the fly to some other place. The example will be in covered in details later.:

tar czf - path/to/dir | ssh 'cat > path/to/archive/dir/archive_file.tar.gz'

Exercise 1.3


  • Find with find all the files in your $HOME that are readable or writable by everyone

    • (*) apply chmod o-rwx to all recently found files with find

  • Make a tar.gz archive of any of your directory, when done list the archive content

  • Extract only one particular file to a subdirectory from the archive

  • Transfer just created archive using sftp (if still time, do the same with scp and rsync).

    • (*) Try ssh+tar combo to make transfer and archive on the fly.