! ^

- Use ! to repeat the last command typed at the keyboard.
- Use ^ to replace a string from the last command with a new string.  The
   syntax is the same as in csh: "^old-string^replacement"  For example:

> tell rasmusse Hi there, how are you?
No-one by that name here.

> ^rasmusse^rasmussen
You tell Rasmussen, 'Hi there, how are you?'

> ^you^you doing^
You tell Rasmussen, 'Hi there, how are you doing?'