CTRL-r is your friend!

You already knew that the up and down arrows in a Linux terminal window allow you to navigate through previously typed commands, but did you know that you can also search through your command history?

CTRL-r is great for finding those commands that are a bit tedious to type.

When you type CTRL-R in a terminal window your whole prompt turns into this strange looking text:

(reverse-i-search)`':

As you type characters the first command in your history, starting from the most recent and working back towards the top will be displayed.

Let’s say you’ve typed the following list of commands:

sqlplus / as sysdba
rman target "'/ as sysbackup'"
ls
ls -als

At a command prompt you type CTRL-r and then type s. Your prompt will now look like this:

(reverse-i-search)`s': ls -als

And the s in the als will be highlighted. What you’ve done here is found the first s in your command history.

If you type Enter right now, you’ll rerun that command.

Things get more interesting when you start typing more letters. Instead of typing just s, type sq and you’ll get the following:

(reverse-i-search)`sq': sqlplus / as sysdba

Hitting Enter will rerun that sqlplus command.

What if you want to find something that you typed earlier than the last command that matched? Just type CTRL-r again. Each time you press CTRL-r you’ll find older and older strings that match. If you have a short search string (just s for example), then it’s not unusual to find that string in a single command multiple times. Once you’ve exhausted all the matches in one command, you’ll reach back into your history to find another that matches.

What if you want to find the last thing that you found with CTRL-r?

Start a new search (or just use backspace to remove any characters you’ve started typing) and press CTRL-r again. Let’s say that you used rm as your last successful search and retrieved the rman command from the above list of commands. You then ran a few more commands and decided to run rman again… Just type CTRL-r twice. The first CRTL-r says “I want to search through my history”, the second CTRL-r says “Remember the last successful search I used? I want that one again.”

What if you don’t want to run the command you found, but instead you just put the command at your prompt so you can edit it? Instead of hitting Enter after you find a command, just press Esc. This dumps the text of the command into your terminal at a command prompt.

Here’s where things get really cool… If you use rlwrap for various Oracle commands like sqlplus, rman, etc. (See this post to install rlwrap, and this post to configure the aliases to use with rlwrap) then CTRL-r will also work in those commands too!

Want to find the last alter user command that you ran? In sqlplus just type your good friend CTLR-r and start typing alter. You probably won’t have to actually type all the letters in alter and soon you’ll have the following:

(reverse-i-search)`al': alter user dbsnmp identified by oracle_4U account unlock;

Technically CTRL-r finds the spot in your history where the command you found lives, so once you’ve found a command, you can use the up and down arrows to cycle through the commands that are near that command. What was that command that I typed right after I did that alter user command? Just press the down arrow key and you’ve found it!

There are a few idiosyncrasies with CTRL-r. First it is case sensitive so you’ll have to remember if you used SELECT or select. Second it can be kind of easy to get it into a strange place with the characters you are searching for if you start typing characters that are not actually in your command history CTLR-r will beep at you a bunch and you may or may not be able to use the backspace key to get back to where you want to be… Just use Esc to get out of the CTRL-r search and try again.

Also you may want to give CTRL-r more history to work with. If you’d like to do this you’ll need export two different environment variables, HISTSIZE and HISTFILESIZE.

I added the following to my .bashrc file in my home directory:

# Let's give the history command and CTRL-r more to work with!
export HISTSIZE=10000
export HISTFILESIZE=10000

CTRL-r has saved me much typing over the years, I hope it helps you too!


Thoughts on the Oracle users bashrc and bash_profile

For many, many years we’ve been clouding up the oracle user’s .bashrc and .bash_profile scripts with ‘lots of things’. Some of these things will be set automatically when we run the . oraenv command (that’s dot space oraenv). Our good old friend LD_LIBRARY_PATH gets set automatically, ORACLE_HOME gets set automatically, and the PATH is extended to search in your ORACLE_HOME/bin directory.

The below screenshot comes from a ‘new’ Oracle Linux 6 system where I’ve done a software only install of Oracle Database 12.1.0.2 and have yet to create any databases. Because I don’t have a database yet, I have to type in the path to the ORACLE_HOME when I give some random SID. Once I have a database created, that database will get added to the /etc/oratab file and the SID will be recognized and automatically set the ORACLE_HOME for me.

bashrc and bash_profile

Click the image above to get a full size picture of what’s happening.

Based on the above, I might change things a bit in this post from my 12c Install Series.


Oracle BI Publisher Desktop on 64 bit Windows with 32 bit Office

While working on a client’s machine today I ran into a kind of strange issue. They have 64 bit Windows, but have stuck with 32 bit office and no matter what I tried I couldn’t get the BI Publisher tool bar to work at all…

Every time I installed BI Publisher Desktop and went into word I would see the following situation when looking in the Word plugins:

BI Publisher Template Builder for Word is in the Inactive Application Add-Ins section

Looking at the Manage COM Add-ins details, I could see the Template Builder, but had the following error.

Load Behavior: Not loaded. A runtime error occurred during the loading of the COM Add-in.

Various blogs suggested various fixes (Like Tim Dexter’s excellent post here: https://blogs.oracle.com/xmlpublisher/entry/template_builder_woes_1 ), but they appeared to suggest that you needed MS Visual Studio to get things to work.

After a bit I opened up an SR with Oracle and eventually we figured out that you can install the following: MS Visual Studio 2010 Tools for Office Runtime to get the necessary Visual Studio parts so that the Template Builder will work.

After installing that, everything worked like it should have.

Hopefully this will help someone some day…


Helping others

Part of this series of posts: Oracle Database 12c on Oracle Linux 6

One of my students at ACC suggested that I put this document up for sale on Amazon.

Instead I’ve decided to do the following:

  • Please consider opening an account on Kiva.Kiva is a non-profit organization with a mission to connect people through lending to alleviate poverty. Leveraging the internet and a worldwide network of microfinance institutions, Kiva lets individuals lend as little as $25 to help create opportunity around the world.If you use the below link you can get $25 to lend to others to get you started. I’ll also get $25 to lend to others. Technically the $25 to lend is a limited time offer, so you and I may not get this ‘bonus’ money to lend.http://www.kiva.org/invitedby/richard4068

 

I couldn’t have done it without you… < Previous Post


I couldn’t have done it without you…

Part of this series of posts: Oracle Database 12c on Oracle Linux 6

I made this document because I’ve seen folks struggle with some of the concepts in the document. Of course this document wasn’t created in a vacuum. Various blogs, the Oracle forums, a ton of Google searches and a lot of trial and error went into this document. To those that helped me in some way with the content in this document, thanks!

 

Oracle Database 12c on Oracle Linux 6 – Step 31: Enjoy a frosty beverage! < Previous Post – Next Post > Helping others


Oracle Database 12c on Oracle Linux 6 – Step 31: Enjoy a frosty beverage!

Part of this series of posts: Oracle Database 12c on Oracle Linux 6

31-01

If you’ve made it this far, congratulations! Open a frosty beverage of choice and pat yourself on the back. You deserve it!

 

Oracle Database 12c on Oracle Linux 6 – Step 30: Install the VirtualBox guest additions in the VM < Previous Post – Next Post > I couldn’t have done it without you…


Oracle Database 12c on Oracle Linux 6 – Step 30: Install the VirtualBox guest additions in the VM

Part of this series of posts: Oracle Database 12c on Oracle Linux 6

30-01

Select Devices -> Install Guest Additions… from the VirtualBox menu. You’ll have to use the right Ctrl key to release the mouse to do so.

30-02

Click Cancel.

30-03

Right-click the desktop and select Open in Terminal.

30-04

Type the following commands, pressing Enter after each.

su - 
root (at the Password: prompt)
export KERN_DIR=/usr/src/kernels/`uname –r`
cd /media/V [TAB]
./VBoxLinuxAdditions.run

Note:

Those are back ticks which are probably next to the 1 key on your keyboard, not forward ticks in the export command. The Tab key will autocomplete commands for you. When we type cd /media/V the shell will complete the name of the Virtualbox Guest Additions CD for you. It’s much easier than typing it. If you’d like to use the Tab key to autocomplete the second command, you’ll have to type up to the L in Linux before it will work because there are other commands in that directory that start with VBox. You can always hit the Tab key twice to see what the shell will be able to autocomplete based on your search path.

30-05

You should see output with all green OKs.

Note:

If you get a failed message it’s most probably because your kernel doesn’t match the kernel sources which usually means that your yum update kernel-uek-devel command from earlier didn’t work correctly. Recheck your commands from Step 9 to make sure you did everything correctly.

30-06

Select System -> Log out oracle… from the menu.

30-07

Click Log Out.

30-08

Press Enter and type oracle in the Password field.

30-09

Right click the Guest Additions CD and select Eject.

30-10

Your window should now resize to fill the whole screen!

Note:

We could actually do this step a lot earlier and get the nice widescreen if we want. It was just a bit harder to do screen captures for me so I stuck this at the end. This must be done AFTER the reboot in step 18 though…

Oracle Database 12c on Oracle Linux 6 – Step 29: Create a Link to SQL Developer and Database Connections < Previous Post – Next Post > Oracle Database 12c on Oracle Linux 6 – Step 31: Enjoy a frosty beverage!


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