[ILUG] Shell tip: bang commands...

[Niall O Broin]

On 14 May 2006, at 02:48, Sarah Fortune wrote:

> kevin lyda <kevin at ie.suberic.net> quoth:
>> Getting stuff from the last command:
>>
>>     Full line:     % !!            becomes:   % vi foo.c bar.c
>>     Last arg :     % svn ci !$     becomes:   % svn ci bar.c
>
> In bash you can use Alt-. to fill in the last argument, it's nicer  
> than !$
> because you can see what it is before running the command.

This also has some nice additional features. Repeatedly pressing  
Alt-. cycles back through the history, replacing into the command  
line the last argument from each line in turn, and it's also possible  
to get an argument other than the last. Also, this shortcut key is  
actually Meta-. (also Meta-_) where Meta means the Meta key, when  
available (the diamond on a Sun keyboard, for instance), and is  
usually mapped to the Alt key on a PC style keyboard and conveniently  
for remote usage (where special modifiers like Alt and Meta can often  
not be used) Meta-X can be replaced by Esc X .

These convenient features are provided to bash courtesy of the GNU  
readline library, which is also used in other programs and is  
available to anybody who's writing a program with a command line. man  
readline will provide a good introduction to its many useful features  
- my most used one would be reverse-search-history, bound to Ctrl-r  
by default - you'll rarely need to do  history|grep  again.

  Because it's readline the keys used are configurable (defaulting to  
emacs like, of course, but there's a vi mode for the afflicted).


Niall