1) Installing Vbox guest addition using VBox option, where we choose from the virtualbox menu “Devices” and then Install guest additions does not work directly. So run terminal and log in as the root with choosen password (sudo su). Then:
The mod_ssl module provides strong cryptography for the Apache Web server via the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols. How do I install and configure mod_ssl under CentOS / Fedora / Redhat Enterprise Linux?
mod_ssl is the SSL/TLS module for the Apache HTTP server. You can use self signed certificate or 3rd party SSL certificate. This module provides SSL v2/v3 and TLS v1 support for the Apache HTTP Server. It was contributed by Ralf S. Engeschall based on his mod_ssl project and originally derived from work by Ben Laurie. This module relies on OpenSSL to provide the cryptography engine.
The lines that the user needs to enter or customize will be in red in this tutorial!
The rest should mostly be copy-and-pastable.
About SSL Certificates
A SSL certificate is a way to encrypt a site’s information and create a more secure connection. Additionally, the certificate can show the virtual private server’s identification information to site visitors. Certificate Authorities can issue SSL certificates that verify the server’s details while a self-signed certificate has no 3rd party corroboration. Continue reading →
I am pretty sure I’ve mentioned that among my various other duties at work, I manage the network security program as well. One of the things we have to do on a regular basis, which I think all companies should do, is perform frequent penetration tests on our public web servers. It is good to find your holes, and plug them up before the bad guys do. I mean, you hear about it all the time where companies report security breaches where millions of their users credit cards are stolen. If they were performing regular scans, they may have been able to prevent that. Continue reading →
Joining MP3 files can be rather simple task with a cat command. Suppose we have a directory with multiple MP3 files. The following cat command will join all MP3 files in a current directory to a single file called out.mp3:
$ cat *.mp3 > out.mp3
If we wish to join only specific files we can name them on a command line separately:
The find utility on linux allows you to pass in a bunch of interesting arguments, including one to execute another command on each file. We’ll use this in order to figure out what files are older than a certain number of days, and then use the rm command to delete them.
Vi is an one of two powerhouse text editors in the Unix world, the other being EMACS. While obtuse, vi is extremely powerful and efficient. There may be times when vi is the only text editor available, so it helps to at least know the basics.
On Mac OS X (and Linux), vi is symlinked to vim (vi improved), a more modern free software version. Vim It is the default editor when changing a crontab.
One thing Ubuntu lovers like about Ubuntu is that it is “user friendly”, to me, it is “user friendly” only if the user doesn’t know what he is doing.
As an example I have automatic updates, it may be convenient that your operating system search for updates for you (If you do not know how to do it, or do not want to do it by yourself). But it is also annoying to have a pop-up appearing when you are working, just to remember you something you already know. I prefer to turn off automatic update feature. Continue reading →
Like UNIX commands, shell scripts also accept arguments from the command line.
They can, therefore, run non interactively and be used with redirection and
Arguments are passed from the command line into a shell program using the
positional parameters $1 through to $9. Each parameter corresponds to the
position of the argument on the command line. Continue reading →