ssh, compress, scp

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layout: post
title: "ssh, compress, scp"

ssh config for server

SSH/OpenSSH/Configuring

ssh connect

SSH/OpenSSH/ConnectingTo

From Unix-like systems (including Mac OS X)

To login to your computer from a Unix-like machine, go to a command-line and type:

 ssh <username>@<computer name or IP address>

For example:

ssh joe@laptop

or:

ssh mike@192.168.1.1

You should get the usual password prompt (or be told you can't log in, if passwords are disabled).
See ssh keys if you want to authenticate using keys instead of passwords.

compress/extract file

Extracting a tar.bz2 file

• Extract tar.bz2

tar jxvf <filename>.tar.bz2

This will show you what it extracts, and in most cases will create a directory named <filename>.

• To extract a tar.gz, simply put z in place of j in the command line. For more information please refer to man tar.

Creating a tar.bz2 file

  tar jcvf <filename>.tar.bz2 dir1 dir2 file1 file2 ...

<filename>.tar.bz2 is the name of the tar file we wish to create. dir# and file# are the names of the directories or files we wish to include in the tar.bz2 archive.

• To use gzip compression instead of bz2, simply put z in place of j in the command line.

For more information please refer to man tar.

Rar

Rar v3.0 archives require the use of unrar.

unrar-free

• Extract .rar

 unrar-free <filename>.rar

If extracting fails with a message like the following, try the non-free version.

Extracting  file1.ext Failed
Extracting  file2.ext Failed
2 Failed

unrar-nonfree

• Extract .rar

unrar x <filename>.rar

zip and unzip

• To create a zip file containing dir1, dir2, ... :

zip -r <filename>.zip dir1 dir1 ...

• To extract .zip:

unzip <filename>.zip

scp

Another important function of SSH is allowing secure file transfer using SCP and SFTP.

Secure Copy (scp)

To copy a file from your computer to another computer with ssh, go to a command-line and type:

scp <file> <username>@<IP address or hostname>:<Destination>

For example, to copy your TPS Reports to Joe's Desktop:

scp "TPS Reports.odw" joe@laptop:/home/joe/Desktop/

To copy the pictures from your holiday to your website, you could do:

scp -r /media/disk/summer_pics/ mike@192.168.1.1:"/var/www/Summer 2008/"

The -r (recursive) option means to copy the whole folder and any sub-folders. You can also copy files the other way:

scp -r catbert@192.168.1.103:/home/catbert/evil_plans/ .

The '.' means to copy the file to the current directory. Alternatively, you could use secret_plans instead of '.', and the folder would be renamed.

Secure FTP (sftp)

Finally, if you want to look around the remote machine and copy files interactively, you can use SFTP:

sftp linus@kernel.org

This will start an SFTP session that you can use to interactively move files between computers.