Watch

In this post I am going to write about very useful utility called watch and its possible usages. I discovered it several weeks ago, but since then I use it quite often. It’s a pity that I didn’t know about this program all the time that I had been using Linux. This utility executes given program periodically, showing output fullscreen. It can be used to monitor any kind of information about your system.

Below you can find some examples:

• Monitor wireless connection (bit rate, signal quality and so on):
  

  watch -n1 -d /sbin/iwconfig eth1

• Monitor CPU temperature:
  

  watch cat /proc/acpi/thermal_zone/TZS*/temperature

• Monitor CPU frequency:
  

  watch sudo cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq

• Monitor disc usage:
  

  watch df

And of course (as with almost any UNIX utility) you can invent a lot of other ways how to use watch.

Posted by ksh on August 21, 2006 | 1 comment | linux

Short guide to Wi-Fi under Linux

Recently I bought notebook and needed to connect to hotel Wi-Fi network (to install Gentoo linux :) All information that I’ve found didn’t help me to setup wireless connection in less a minute. This guilde explains (in very simple way) how to connect your PC to Wi-Fi network under linux.

You should have following applications installed on your PC:

• Wi-Fi driver (this guide covers Intel 3945)
• wireless-tools
• dhcp

Follow these 7 simple steps:

1. Load Wi-Fi driver (Intel 3495 specific):
   

   modprobe ipw3945
ipw3945d

2. Figure out the name of network interface that is bound to Wi-Fi card:
   

   iwconfig

3. Find list of available networks:
   

   iwlist scanning

4. Connect to one of it:
   

   iwconfig eth1 essid ESSID

   
   where eth1 – network interface found at the second step and ESSID – id of wireless network found at the third step
5. (optional, I haven’t used it) If network is secured you should also specify key:
   

   (This sets a hex WEP key)
iwconfig eth0 key 1234123412341234abcd
(This sets an ASCII key – prefix it with “s:”)
iwconfig eth0 key s:some-password

6. Obtain IP address using DHCP:
   

   dhcpclient eth1

7. Make sure that everything is ok:
   

   ifconfig

Probably these steps are too simplistic and will not work in all cases, but they work fine for me and when I was in need for simple instructions I haven’t found such small guide.

Posted by ksh on August 16, 2006 | 1 comment | linux

I am in London!

I have changed my previous job and now I work in London.

Yesterday I arrived to the city and today was my first day at new job!

London is really great and full of things to discover :)

I already seen Big Ben on the way from airport to the hotel.

Posted by ksh on August 1, 2006 | 1 comment | personal