Skip to main content

Quickly: Command history in Linux / Shell

If you are like me, doing a lot of command line in linux (Bash) shell, there are a few commands you do very often. The following commands will make your life a lot easier to quickly go back in command history.

[!!] or better yet [sudo !!] - [!!] is an alias for last run command. One of the best use of this is - Sometimes, you type a command and the shell hits you back with a root privileges required message. You dont have to copy the command and run again. just run [sudo !!]

[history] - just spits out ~/.bash_history with line numbers. A good use of this is piping it to grep to find something. The line numbers can be used to execute the command following it. Say for example, [history | grep find] lists the previous searches (okay, it also shows all commands with "find" anywhere in the line - but a filtered, smaller list).
$history | grep find
 457  find *.wav
 462  find *.wav -exec lame --preset fast extreme '{}' '/tmp/mp3/{}' \;
 487  find *.wav -exec mp3cvbr '{}' \;

To rerun the search just type !nnn where nnn is the number of the line shown, eg: !462.

And the best one..
[CTRL+R] Dont *type* it - press control + r on your keyboard at shell prompt. It opens a prompt that will start a reverse search on history of commands. Then, Type any part of the command (or arguments) that you have done in the past, it will fill in the whole command including the arguments. Hit Enter to execute it!!

Popular posts from this blog

One page Stock

Alright.. That was a long absence. The whole last week I dint blog. I dint go away. I was "occupied". I was learning stock trading. Its very fascinating. I have a good weeeked blog for you all. Here is my experience. I can literally hyper-link every word from the following paragraphs, but I am writing it as simple as I can so you can look up the italicised words in wikipedia . I got a paper trading account from a brokerage firm . You need one brokerage account first. Then it can be an Equity account where all your money is yours or a Margin account , where some of the money is lent by the brokerage firm. Then I get Buying power , which is the dollor value of how much stocks you can buy. I can make profit by simple rules. Buy when Price is low. Sell when price is high. There is another more intersting way of earning money. Selling short . Thats when price is not high, per say, but when are confident that the price WILL go down. then buy back when its lowest. This is what

Powered By

As it goes, We ought to give thanks to people who power us. This page will be updated, like the version page , to show all the tools, and people this site is Powered By! Ubuntu GIMP Firebug Blogger Google [AppEngine, Ajax and other Apis] AddtoAny Project Fondue jQuery

classpath*: making your Modular Spring Resources

Spring gives multiple options to load XML resources for building contexts. the reference documentation does explain this feature quite well. However, I am taking my shot at explaining the different practical scenarios ( by order of growing modularisation) For Example, A simplest Spring based web Context Loader can be configured with resources like this <context-param> <param-name>contextConfigLocation</param-name> <param-value>applicationContext.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> You just need to put applicationContext.xml in WEB-INF/ folder of your webapp. However, Typically an application is n-tiered. You can also have multiple files setup and in relative paths. like <param-value> context-files/applicationContext.xml context-files/dao.xml context-files/service.xml </param-value>