To change your login shell, you need to modify your line in that file. However, you can't just edit the file (because if you could you could modify other people's login shells, and do some nasty things).

chsh is a program that:

• checks the new shell you've asked for against a list of allowed shells (created by the system adminstrator)
• makes you prove you're the person sitting at the keyboard who actually logged in there (by asking for your password and checking it)
• acquires root privilige
• edits /etc/passwd to update your login shell entry

For chsh to work, a number of things are required:

• you have chsh installed
• the sys admins have set things up so it works (primarily, so that when it tries to verify your password it is able to do so)

At the moment, we're experiencing the following problems. They may be fixed by the time you try, or maybe not:

• attu: chsh fails trying to verify your password
• some cygwin installations: no chsh installed

If you have problems using chsh, you can do the rest of the assignment by just continuing with the instructions on the main page. (In particular, you launch a bash in sub-step 3 of step 2.) That will let you talk to bash until you logout of that shell, but it won't cause bash to be your shell the next time you login.