jim.bernatowicz

Arrrgh! Arrrgh!! Is it September 19th already?

Sadly, no. I just wasted a good number of hours with my Skype setup on Ubuntu 8.10, then 9.04, then 9.10! Hours of my life that I'll never get back!

Last night I decided to try out the new features and call quality improvements promised in the latest 2.1 beta 2. I uninstalled Skype 2.0.0.72 and installed Skype 2.1.0.81 beta 2. First thing I noticed was that the call audio was played through my laptop speakers, not my USB uConnect U-901.

Tonight I was searching for some tools to create screencast videos. I found recordMyDesktop, which records audio and video, but outputs the video in an ogg file format.

In looking for a way to convert ogg files to Flash video flv format, I stumbled across this very interesting how-to on video editing with the ffmpeg program.

Its very important to firewall your server if its directly connected to an untrusted network.

I put together this sample for my box by using this helpful iptables tutorial.

This configuration allows any outbound traffic, and inbound requests only on ports 25, 80, 110, 443, and 37530. Everything else gets sent to the LOGNDROP rules which log the attempts on syslog, but no more than 5 per minute, and then discards the packets.

ifconfig
Shows network adapters, IP addresses, and can be used to bring adapters up and down.

sudo dhclient -r
DHCP release of IP address. Equivalent to ipconfig/release on Windows.

sudo dhclient
DHCP renew or request of IP address. Equivalent to ipconfig/renew on Windows.

sudo netstat -tap
Shows processes that are listening, and other active network connections. You must run as super user to see the owning processes.

sudo nmap -p1-65535 -sS -sV -O -PI -PT <IP / Hostname>

ps
Shows the process status of your processes.

ps aux
Shows all of the processes in detail.

top
Shows the "top" processes in full-screen mode, refreshed every second. There is also summary information at the top in terms of memory usage, CPU utilization, load averages, and system uptime.

kill (process id)
Requests that the process terminate. (This sends a TERM signal.) If the process does not terminate, follow-up with the larger hammer shown below.

kill -9 (process id)

Netbeans is a powerful IDE (integrated development environment) that supports many languages. It got its start as a Java IDE, and in fact its written in Java, so it runs on Windows, Linux, and Mac.

Netbeans is open source and free of licensing costs.

At the time of this writing, I am using Netbeans 6.8 for PHP development.