Tuesday, 3 September 2013

Show vendor when searching through installed RPMs

This is done using the %{VENDOR} tag. For example:-

rpm -qa --qf '%{NAME}-%{VERSION}-%{RELEASE} %{VENDOR}\n'

Monday, 2 September 2013

Highlight all occurences of selected word in vi

To do this:-

:set hlsearch

To undo this:-

:nohlsearch

Show line numbers in vi

:set number

Rebuild RPM DB

This may need to be done in instances where simple commands such as rpm -qa hang. Steps:-
  1. Kill all rpm and yum processes
  2. yum clean all
  3. rm -f /var/lib/rpm/__db*
  4. rpm -v --rebuilddb
  5. yum makecache

Tuesday, 23 July 2013

Mac Tips and Tricks

Recently I have been using a Macbook Pro for work (OS X 10.8.3), it's good but I have come across a few things that I am not used to and have discovered ways to fix them.  

Using Mac with regular UK keyboard
There are several problems:-
- Hash key in the wrong place
- @ key in the wrong place
- " key in the wrong place
- | symbol in the wrong place
- ~ key in the wrong place
- Home and End keys don't work
- Copy and paste are apple + c and apple + v

With regards to the standard keys there are several keyboard layouts you can download and use, the best of which I can find is the British (PC 105 alt) downloaded from the following location:-

http://liyang.hu/osx-british.xhtml

With regards to home and end keys see the following:-

http://lifehacker.com/225873/mac-switchers-tip--remap-the-home-and-end-keys

However the home and end keys still won't work in firefox! For this install the KeyFixer add-on:-

https://addons.mozilla.org/en-US/firefox/addon/keyfixer/?src=search

With regards to copy and paste keys, you can go to System Preferences > Keyboard > Keyboard Shortcuts and set Application Keyboard Shortcuts > All Applications > Add Shortcut

- Copy ^C
- Undo ^Z
- Cut ^X
- Paste ^V  

Scroll doesn't work the same way

This is an easy one to change. Go to System Preferences > Trackpad > Scroll and Zoom > Scroll Direction: natural - untick this.  

Useful Software to install

iTerm2 - pretty similar to terminator in linux (which can also be installed for Mac):-

http://www.iterm2.com/#/section/home

csshX - cluster ssh for Mac:-

http://code.google.com/p/csshx/

Friday, 14 June 2013

Tips and Tricks

Make ps more readable and put on separate lines
 ps -ef | grep java | tr " " "\n"  
Show hidden files with du
 du -sk .[!.]* *| sort -n  
Show just hidden files with du
 du -sh .[a-zA-Z]*  
Trim last character in vi
 :%s/.$//g  
With sed
 sed '$s/.$//'  
Awk, print all on one line with a comma seperating
 awk '{ printf "%s,", $1 }'  
Find command with regex
 find . -name \*[Ii]nstall\*[Ll]og\*  
Remove all blank lines with awk
 awk '/./' abc.txt  
Show octal permissions when doing an ls
for file in `ls`; do echo -n `stat -c %a $file`; echo -n " "; ls -ltd $file; done  
Using awk with a field seperator
 awk 'BEGIN { FS = "," } ; { print $1 }'  
Remove HTML tags from a file
 sed "s/<[^>]\+>//g" file  

Awk print from third column to the end
 awk '{ print substr($0, index($0,$3)) }'  

Monday, 3 June 2013

Passwordless ssh with Puppet

This can be achieved with the ssh_authorized_key resource type. Before doing this in puppet you need to generate a key on the host you want to ssh from. From within the user account you want the ssh access to occur from:-
 ssh-keygen  

Take a copy of the key text from /home/username/.ssh/authorized_keys. This should just be the key part not the ssh type or user and hostname. Also take a copy of the type and the user and hostname part.

Within puppet do the following:-
 ssh_authorized_key {  
  "andy@ahibbert":  
   ensure => present,  
   user  => andy,  
   type  => "ssh-rsa",  
   key  => "AAAAB....."  
 }  

In the above the details from the authorized_keys file are found:-
  • andy@ahibbert - user and hostname I'm ssh'ing from
  • type - the ssh type I am using
  • key - the public ssh key
 This file should be saved with a .pp extension and then applied as follows:-

 puppet apply auto_ssh.pp  

You should know be able to ssh without a password