Linux Shtuff

Hi,

When I started this blog, I started it for my own benefit so I could remember those little tweaks or fixes which escape memory at crucial times when a needed repair or a new issue arose that I had never dealt with before. When I would research these issues, I would come across great posts and information I wanted to remember and posted that information here. I did not give credit where credit was due regarding those posts and if you find something that was posted by you, please let me know and I will credit the post to you. I cannot remember where I pulled all of the information from so, if you see something that is yours, do not fret, I am not stealing your shtuff, I am posting it so all can read and learn from the mistakes and information I have gathered. Most of the posts are mine, but not all. Thank you all for your patience and information you have shared to better improve the linux experience.

Oh and by the way, if you see a post that has outdated or incorrect information, please, please, pretty please let me know so I can update it. Believe it or not, I use this site also and I want my information to be up to date as well. Thanks again for visiting.

How do I password protect / encrypt a file within Linux using OpenSSL ?

The file we will encrypt will be the file secretfile.txt.As you can see it is just a plain text file.

Encrypt File

Use the openssl comand to encrypt your file and then test the new file is fully encrypted.

Decrypt File

Decrypt the file and then confirm the decypted file is readable.

====================================== Read the rest of this entry »

From sourceforge.net

RetroShare is a Open Source cross-platform, private and secure decentralised communication platform. It lets you to securely chat and share files with your friends and family, using a web-of-trust to authenticate peers and OpenSSL to encrypt all communication.

Features

RetroShare provides:

From practicalthought.com

sl takes the most common use of Unix ls, to display the files in a directory compactly in multiple columns, and makes it substantially more useful.

sl groups files by purpose so you can mentally organize many files quickly; for instance, it collects HTML and PHP files together, as opposed to leaving them mixed up with supporting images, CSS, and JavaScript. sl points out interesting files, which include those that have been recently modified, read relatively recently, are relatively large, have warnings, or need to be checked in to or out of version control.

sl is also aesthetically pleasing due to attention to layout and filtering as well as limiting color and text annotations to salient information.

Download Script sl

From practicalthought.com

Hi,

I don’t usually recommend a lot of web based tools but I had to mention this one, sitecheck.sucuri.net. This quick little web based malware/site scanner just saved me about 2 weeks worth of work by locating a segment of .js that was causing a malware warning to be thrown only in certain browsers and anti-virus scanners.

Because the .js was new and buried about 9 layers deep in a wordpress plugin, it would have been nearlly impossible to locate by hand. This tool pulled it up in about 30 seconds. Well done sir web scanner…

sitecheck.sucuri.net

From diademblogs.com

Config Server Firewall (csf) and Login Failure Daemon (lfd) is a robust firewall solution having Stateful Packet Inspection (SPI), Login/Intrusion Detection and Security application for Linux servers. Although it is more compatible with CPanel we have been able to use the same for the Plesk hosting control panel also and it is running fine. Please visit the below link for more information.
From http://www.configserver.com

I have listed the installation steps for CSF / LFD.Login to your server with ‘root’ user and issue below commands :
Change directory to either /root or /usr/local/src , which ever you normally use for such installations

[Remove any old source that might be present]

Download and untar the source for installation

Run installation script

Read the rest of this entry »

You can clear the arp cache using following commands

Current arp cache

Clearing arp cache with verbose

*** Round 1, deleting 1 entries ***
70.167.140.1 dev eth0 ref 42 used 0/0/0 INCOMPLETE

*** Round 2, deleting 1 entries ***
*** Flush is complete after 2 rounds ***

current entries

You can also delete specific arp entries using the two following command

tested on CentOS release 5.7 (Final)

From bilalquadri.com

Here is a nice little addition to vi or vim. You can create a custom theme for vi/vim and download it to use locally. Nice!

From their FAQ:

Where do I put the colorscheme I just downloaded?
The colorscheme should be put in “~/.vim/colors”. If those directories don’t already exist, you will need to create them.

I’m using Vim in the terminal. How can I use my colorscheme outside of gvim?
There are few things to note here:
• Make sure you tell Vim how many colors your terminal supports. Just add this line to your .vimrc file in your home directory:
let &t_Co=256

Use 88 instead of 256 if that’s what your terminal supports.
• Download and unzip this plugin into the ~/.vim directory. After that, you should be set.

How do I change my colorscheme?
Just type “:colorscheme ” in Vim without the quotes. Tochange the default colorscheme, just add that line to your .vimrc file in your home directory.

From bilalquadri.com

Hi,

I ran across a small issue where the client wanted to use vim as the default editor for crontab as opposed to pico. I was able to modify this by using the following commands;

and done…

Now, when editing crontab, it uses vim. Simple.

From mongodb.org
From if-not-true-then-false.com
From php.net

To install mongodb, add the appropriate repo information below for your distribution version (x86_64 or i686) to /etc/yum.repos.d/10gen.repo:

add

or

[10gen]
name=10gen Repository
baseurl=http://downloads-distro.mongodb.org/repo/redhat/os/i686
gpgcheck=0

then run

Check the basic mongodb configuration settings before starting MongoDB (default settings are usually good)

logpath=/var/log/mongo/mongod.log
port=27017
dbpath=/var/lib/mongo

Read the rest of this entry »

As of WHM 11.30, the nameservers’ IP assignments are now read from the Zonefiles and actual DNS queries after recent updates. If you are not seeing the needed IPs in /etc/nameserverips please do not attempt to edit that file, as it is now overwritten by cPanel.

Check under WHM: Main >> DNS Functions >> Nameserver IPs for current nameserverips

(Solutions may depend on the cPanel version)

Problem
The updated A entries and/or NS entries are not retained:
Solution(s)
Add the needed nameservers to the /etc/hosts file

Add (append) a new line, one per IP, onto the existing hosts file such as:

OR

Then run the updatenameserverips script:

Check under WHM: Main >> DNS Functions >> Nameserver IPs again to see if it worked, if not continue

Delete the nameserverips.cache file

Then modify /var/cpanel/nameserverips.yaml to suite

Then run the updatenameserverips script again