Month: September 2009

Webmail not loading

If Whm/Cpanel/Webmail is not loading in ssl mode (2087/2083/2096) then first you can try httpd (stop/start/restart) If it not works then https authentication is usually run by the stunnel for c-panel; and since the error is shown only when data transfer using stunnel is done; you can try a stunnel restart. do the following: ===============…


Write a message to login users through terminal

To write a message to users that have login, you can using the command write. But before that, you need to check who is login, and which terminal he is login to, use command who. Let say you was unable to call your friend, maybe he forgot to bring his cellphone and you know he…


Exim Cheatsheet

For more information on Exim cheat sheets see bradthemad.org Here are some useful things to know for managing an Exim 4 server. This assumes a prior working knowledge of SMTP, MTAs, and a UNIX shell prompt. Message-IDs and spool files The message-IDs that Exim uses to refer to messages in its queue are mixed-case alpha-numeric,…


Generate random password from CLI

Generate a random 8 character password containing a-z, A-Z and 0-9: egrep -ioam1 ‘[a-z0-9]{8}’ /dev/urandom


How to send email from the Linux command line

MAIL First run a quick test to make sure the “sendmail” application is installed and working correctly. Execute the following command, replacing “you@youremailid.com” with your e-mail address. # mail -s “Hello world” you@youremailid.com Hit the return key and you will come to a new line. Enter the text “This is a test from my server”….


Anonymous SSH Sessions With TOR

OpenSSH is a great means to protect your connection from being sniffed by others. However, this isn’t always enough. Simply proving that you connected to a server is enough to get incriminated. Unfortunately, SSH doesn’t provide a native way to obfuscate to whom it connects. Instead, a proxy server can be set up. And this…


Schedule a Tweet with One Comnand in Linux

Ever want to schedule a tweet to go out at the same time an article is published or an event is started? Want to do it without signing up to a service or some other complicated task? Well this post is for you. I am going to show you how to schedule a tweet from…


Blocking SSH probing IPs using a simple script

(from tuxopia.net) I was troubled by the fact that my server was constantly being bombarded with SSH probes for as long as 1 to 2 hours at a stretch. Although the SSH daemon configuration has been tuned for security like disabling root access, allowing only a certain list of users, etc., a continuous SSH probe…


Remove extra virtual terminals

Virtual terminals are a good tool to have—they offer a last-ditch escape to command line for a chance to fix things in a crashing system. But many Linux systems come with six of them enabled, which isn’t usually necessary. You can usually disable five of them with few consequences. If you’re using Gutsy, open a…


How to change your default editor -Debian/Ubuntu

Debian and Ubuntu uses for visudo, crontab and other similar applications the default text editor, you want to change it use the update-alternatives command. It is as easy as, run this on a terminal window. sudo update-alternatives –config editor The options in my Debian system are: There are 6 alternatives which provide `editor’. Selection Alternative…