Author: admin

Bash, System Administration

Detect Wi-Fi Clients on your DD-WRT Router

Here is a script I wrote that scrapes the web interface of a router running DD-WRT. The script looks for the MAC addresses of wireless users. When it sees a MAC address that it hasn’t logged before it issues an alert. To help identify the new equipment, a portion of the MAC address is sent…
Helpful Tools, VBScript

Import Nextel iDEN Contacts to Google

Sprint is decommissioning it’s Nextel iDEN network in 2013. The Nextel network has been very popular with businesses for it’s push-to-talk (PTT) “walkie-talkie“-like service. Several rugged (and bulky) mobile phones like the Motorola i355 and i365 are well adapted to the sometimes harsh environments of field work and clumsy service technicians. Unfortunately it seems that…
Trash to Treasure

Dell Vostro 1000 Backlight Inverter Replacement

An aging Dell Vostro 1000 ended up on my desk the other day. The owner said it had died, when he turned it on some LEDs lit up, but there was no display. It turned out that the backlight which illuminates the LCD panel was not working. This is a common problem with older laptops….
System Administration

Unattended ACPI Shutdown of Windows VMs

As part of a backup script I have some VirtualBox machines shutdown gracefully using the VBoxManage command: VBoxManage controlvm "$VM_NAME" acpipowerbutton This command emulates pressing (not holding) the power button on a modern computer. A compliant operating system should see the event and trigger a shutdown or other response. For ACPI shutdown events to work…
Bash

Bash Snippet: Trim Function

Occasionally I find myself wanting to removing leading and/or trailing occurrences of a character or string from a larger string in bash. A couple common uses are removing quotes, or stripping an unknown number of spaces leading into the data of interest. This can be done pretty easily with other methods such as awk or…
Bash, System Administration

Zombie Process: Killing the Undead

Is your Ubuntu MOTD warning you of a zombie process? Welcome to Ubuntu 11.10 (GNU/Linux 3.0.0-20-server x86_64) * Documentation: https://help.ubuntu.com/11.10/serverguide/C System information as of Thu Jun 28 18:36:57 EDT 2012 System load: 0.0 Processes: 94 Usage of /: 68.2% of 1.79TB Users logged in: 1 Memory usage: 29% IP address for eth0: 10.0.0.10 Swap usage:…