Command history and automated repeats (bash)

[viking60]

We often put together complex commands -....... and then we forget them
How can we reuse those brilliant pieces of (lacking) know how or how can we find them again? You know -that brilliant tip from the guru on that site that you forgot - needless to say you forgot the command itself......but it was something with urpmi

Fear no more the

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history

command will come to your rescue
It will give you the list over all commands executed and in historical order:

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  990  ssh viking60-server
  991  sudo urpmi --auto-update -a
  992  ssh viking690-server
  993  ssh viking60-server
  994  sudo poweroff
  995  wpa_supplicant
  996  sudo wpa_supplicant
  997  cd /etc
  998  ls
  999  history
 1000  sudo urpmi --auto-update
 1001  ls
 1002  history


It does not care if the command was correct or not - this is the history right or wrong -basta!

Now i find that

sudo urpmi --auto-update -a

hard to remeber so I will just execute it by executing its number in the history table.
Like this:

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!991

And wonder of all wonders it is executed directly

Now this can be a bit dangerous because I do not get a peek at the command first - it just executes. And that could potentially
So how do I get to have a look at the command first?

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!991:p

Will do it! By adding the :p (for peek) you can have a look at it first.

To add the previous command you can do a:

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!!

or

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!-1

To add the command before that you can do a:

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!-2

and so on.
So to have a peek at three commands back what do we do?
You guessed it:

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!-3:p

But it gets better
I am lousy with numbers and I don't even remember what I did one command back But I know it was starting with sudo urpmi so I do a:

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!sudo urpmi

And there it goes - doing the

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sudo urpmi --auto-update -a

If I want to have a look at the command starting with urpmi?

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!urpmi:p

Or the last command starting with pacman (Arch):

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!pacman:p

etc etc...
You do not even need to remember the entire command. If you want commands executed with ssh and only remember ss just do a:

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!ss:p

It will output something like this;

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$ !ss:p
ssh viking@viking60-server

I just needed to write this down in case I forget

[rolf]

This is very good. Using konsole, where 'Ctrl-r' will step back in history, and having done several new installations, saving /home, recently, I think I run up against a limitation for going back, albeit konsole scrollback is set to unlimited and, I figure, this record is kept in my $HOME.

Also, 'Ctrl-r' seems to break down as soon as I typo, so that is not so nice.

It looks like your Tips and Tricks is more powerful, thanks!

[viking60]

And there we have another tip from our Guru:
Hit <CTRL>+r and enter the search word. It will have the same effect, and do an even more elegant search. Thanks! (Well... unless you do a typo )
In fact I can even correct typos in my Mandriva 2010.2