when pkill isn't sufficient to kill firefox

Firefox hanged and I closed it. Restarting it the message came restart or stop firefox. Pkill command normally sufficient didn't suffice to kill firefox.
pgrep firefox listed two processes.
killing these processes by kill , didn't work either.

killall -9 firefox-bin

did the trick.
source: http://www.cyberciti.biz/faq/kill-process-in-linux-or-terminate-a-process-in-unix-or-linux-systems/

for the record:

This is an oldie but a goodie:

1. When a program gets hung, hit Alt + F2 to bring up the Run dialog.
2. Type in xkill and hit enter.
3. Your mouse cursor will change into a cross or skull and bones.
4. If the unresponsive application is not in focus, use Alt-Tab to switch to it. Left click anywhere on the application window to kill it.

Ctrl+Alt+Del to open System Monitor

In Ubuntu

If you want to enable Ctrl+Alt+Del to open System Monitor you have to do this:

Run in terminal:

gconftool-2 -t str --set /apps/metacity/global_keybindings/run_command_1 "Delete"
gconftool-2 -t str --set /apps/metacity/keybinding_commands/command_1 "gnome-system-monitor"

Manual updating grub when a new kernel is installed

If you have a manually adapted grub menu.lst ( found in /boot/grub) you will have to be very careful updating the kernel.
There will be asked if you want to keep your our grub file or the proposed one by the package distributor. Take the last choice but only after you have saved your old copy of the menu.lst as for instance menu_old.lst so that you can adapt the automatically renewed menu.lst to its former state with its renewals of the new krnel incorporated of course, but with the adaptions you made mostly to suit your own special setup on more partitions.
Do it right away before you reboot or else you will probalbly have great trouble rebooting! In terminal (or open your file manger as root)

sudo gedit /boot/grub/menu.lst

Ifconfig and iftop and etherape network monitors

ifconfig (type in terminal) gives you good info on your network connections.
A nice terminal program is iftop. Etherape is a very informative gui program.

ifconfig

The Unix command ifconfig can function as a tool to configure a network interface for TCP/IP from the command line interface (CLI).This is another easy tool to see if your interface is actually loading correctly.

Example

ifconfig

eth0 Link encap:Ethernet HWaddr 00:0A:E6:C6:07:85
inet addr:132.18.0.16 Bcast:132.18.0.255 Mask:255.255.255.0
inet6 addr: fe80::20a:e6ff:fec6:785/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:18458 errors:0 dropped:0 overruns:0 frame:0
TX packets:8982 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4015093 (3.8 MiB) TX bytes:1449812 (1.3 MiB)
Interrupt:10 Base address:0xd400

Route

This is very useful to check routing config

Example

route -n

Netstat

If you want to see Routing Tables,all open ports,all listen ports

netstat -nr

-n means return numeric output (ie, IP address instead of hostname)

-r means print the routing table

find all open ports

netstat -a

find listening ports

netstat -l

http://www.ubuntugeek.com/ubuntu-network-troubleshooting-tips.html

++++++++++++++++++++++++++++++++++++++

If you use a router or gateway, chances are that your network is even further locked down. To check, you can run the following commands:

Code:

sudo apt-get install nmap curl

and then:

Code:

nmap -P0 $(curl www.whatismyip.org

The second command may take several minutes to run, but will give you an accurate picture of which (if any) ports are open to the world outside your home network.

How can you check if iptables is blocking the packets ?

sudo iptables -L

Set Open Port for iptables

sudo iptables -I INPUT -p tcp --dport <> -j ACCEPT
sudo iptables -I INPUT -p udp --dport <> -j ACCEPT

If you want to have help enabling port forwarding in your router: http://www.portforward.com/english/routers/port_forwarding/routerindex.htm

mounting external HDD 2

Sometimes the external hard disk drive won't mount. Maybe this is the problem:

The stupid thing you won't get a response or fault message using Storage Device Manager.
Using : sudo mount -a you will get:

Mount is denied because NTFS is marked to be in use. Choose one action:

Choice 1: If you have Windows then disconnect the external devices by
clicking on the 'Safely Remove Hardware' icon in the Windows
taskbar then shutdown Windows cleanly.

Choice 2: If you don't have Windows then you can use the 'force' option for
your own responsibility. For example type on the command line:

mount -t ntfs-3g /dev/sdb1 /media/sdb1 -o force
Trying this the HDDF is indeed mounted

logitech webcam driver

I seem to have the Logitech Quickcam Communicator.
Found a driver here
More info here

adblock verification didn't work_Solved

Problem: adblock extension couldn't be installed because of Startcon verification failure:
Error: message: Signing could not be verified. -260.

This is essentially the solution:

ENABLE THE VERFICATION ON CERTIFICATE

1. Start Firefox (if it isn’t already). This assumes FireFox version 3+ so menu item names below may differ for other FireFox versions but you should be able to browse to something that has a list of certificates (See image below).
2. Go to Edit -> Preferences. New panel appears.
3. On the new panel, click Advanced category followed by the Encryption tab then View Certificates button.
4. Browse down to VeriSign certificates. You may see something similar to the below:
   
5. Notice in the above image the highlighted certificate "Verisign Class 3 Public Primary Certification Authority" I’ve chosen. It matches exactly what we got highlighted in orange earlier in step 6 from first part above.
6. Click Edit on the highlighted. You should be presented with three choices:
   This certificate can identify web sites.
   This certificate can identify mail users.
   This certificate can identify software makers.
7. Check off "This certificate can identify software makers."
8. Click Ok to save then Ok on other open panels or Save as the case may be and restart FireFox.
9. Try to download your extension again. The error should be gone.
10. You’re done!

Where I found this this was described as a solution for a problem installing a google extension
There Verisign was the verificator.
But which is the verifier for Adblock?
Here I found the answer : StartCom. everywhere you read Verisisgn replace it by Start.com and youŕe done.