SSH Access

The SSH protocol can be used to log on to your PowerNet computer and to gain access to your home directory. SSH is a secure alternative to the Telnet protocol, since all data traffic is encrypted. In order to be able to access your home directory, you must first activate your personal website, which you can do by using the Control Panel (Account menu -> Website). Under Windows you need to download a client program to use the SSH protocol. We recommend the terminal emulator PuTTY, which you can download free of charge. To download and use PuTTY, please follow these steps:

  1. Open the following website: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

  2. Save the file "putty.exe" on your computer, preferably on your desktop for fast and easy access. To do that, right-click on the file name and select "Save target as", then choose a target folder for the program (the program does not need to be installed, the entire application is just the one executable file).

  3. After it has been transferred to your desktop, double-click the file. The following window should appear:

    wu.ac.at

  4. Enter login.wu.ac.at in the "Host Name (or IP address)" field.

  5. Choose the "SSH" protocol as your "Connection type".

  6. Finish the configuration procedure by clicking "Open".

  7. In case the following security alert window appears while establishing a connection to the server for the first time, click "Ja".

  8. The login screen will appear.

  9. Enter your AFS identification (a lower-case "h" followed by your student ID number) when prompted for your login name ("login as") and press the enter key.

  10. Enter you PowerNet password and press the enter key.

    wu.ac.at

  11. A connection has been established to the server and you have gained access to your home folder.

Important commands

After establishing a connection to the server, you can execute a number of commands in your home directory. The most important commands are described in the following section:

Displaying directory contents

The ls command displays a directory’s contents, the "-la" option yields more detailed file information on file permissions, file owners, file size, date of last modification, etc.

Examples of valid commands:

ls

ls -la

Changing directory

By executing the cd command you can change directories. The directory’s name must be supplied as an argument.

Examples of valid commands:

cd public_html

cd homework

Creating a directory

The mkdir command creates a new directory. The directory’s name must be supplied as an argument.

Examples of valid commands:

mkdir homework

mkdir testdirectory

Deleting files or directories

The rm command deletes a file. Adding the "-rf " option deletes entire directories and their contents. The file or directory name must be supplied as an argument.

Examples of valid commands:

* rm index.html

* rm -rf homework

Editing a file

You can edit files with an editor. Commonly used editors are vi and pico. The vi editor offers comprehensive functionality but takes some time to get used to. The pico editor is an easy-to-use text editor. To use it, you must enter the editor’s name followed by the file name you want to edit.

Examples of valid commands:

* vi index.html

* pico test.html

Getting information on storage space

The fs command provides information on AFS volumes.

In combination with "help", it provides an overview of available functions. In combination with "lq" [ListQuota], it provides an overview of storage space.

Examples of valid commands:

* fs help

* fs lq