Firefox & Gmail problem

Gmail says "Upgrade to a modern browser, such as Google Chrome" but I am using Firefox 8.0.1!
First I was angry at Google, but finally I discovered the cause of this problem:

1. Type in the address bar: about:config
2. Filter the results with: general.useragent
3. Reset all the entries which are bold: Right click and then choose reset.

Upgrade Ubuntu 10.10 to 11.10

I have done an upgrade from Ubuntu 10.10 (Maverick Meerkat) to 11.10 (Oneiric Ocelot) using the "Update Manager".

First I had to upgrade to 11.04 (Natty Narwhal). This worked fine and after reboot I launched directly the second upgrade to 11.10.

Here I report the problems and solutions I discovered after the upgrade:

1. Booting did not work: "Failed to load the Nvidia kernel module"
   The reason for this was that the GRUB bootloader was loading the wrong kernel 2.6.35 instead of 3.0.0. Therefore I had to change manually the entry in the grub.conf file:
   kernel /vmlinuz-3.0.0-14 ro root=UUID=932dad41-f43a-4a60-9257-198f026da80e
   
   To find the UUID use:
   df -hsudo blkid
2.  Replace the very annoying "Ubuntu One" standard desktop:
   Install gnome shell: sudo apt-get install gnome-shell
   Logout and login to the Gnome (no effects) desktop.
3. phpmyadmin did not work right away. This problem was discussed previously on this blogg.

Install MySQL with PhpMyadmin in Ubuntu

1. sudo apt-get install mysql-client mysql-server
   Specify the root password for the mysql server when prompted.
2. sudo apt-get install apache2 
3. Try http://localhost in your browser.
4. sudo apt-get install phpmyadmin
5. Add the following line in /etc/apach2/apache2.conf:
   Include /etc/phpmyadmin/apache.conf
6. Now restart Apache:
   sudo /etc/init.d/apache2 restart
7. Access phpMyAdmin under http://localhost/phpmyadmin

Ubuntu basics

Enable the root account:
sudo passwd

Basic plots using octave

Save a figure into a file:

1.  print -deps Speedup.eps
2. use epstopdf

Linux Networking

Set proxy from command line:
Add a new file called 01proxy to your /etc/apt/apt.conf.d/ directory with the following line:

Acquire::http::proxy "http://[user]:[password]@[server_ip_or_name]:[port#]";

 
Cntlm authentication proxy:
 create new authentication:

1. sudo usr/bin/cntlm -c /etc/cntlm.conf -I -M http://test.com
2. enter root password
3. copy the output into the file /etc/cntlm.conf
4. restart cntlm

Create a hot spot with the GNOME network manager:
By using "Create New Wireless Network ..." only an  ad-hoc network is created. These kind of networks are not detected by my htc desire hd phone. See this blog for a discussion.

Linux basics:

Cache

• How can I know my cache sizes? dmesg | grep cache
 
• My CPU is the Intel Core 2 Quad Q6600 @ 2.4GHz:
L1 I cache: 32K, L1 D cache: 32K
L2 cache: 4096K
for each core

Secure Copy (scp)

Copy the file "foo" from local host to a remote host :

scp foobar.txt your_username@remotehost.edu:/some/remote/directory

Finding files
find / -name license.dat

Counting files
ls -laR | wc -l

Software code reuse

Code reuse is a myth says this blog, based on the imperial clothing crisis.

C++

Converts an integer into a string:

(This works also with other data types float ...) 

#include <sstream>
int i = someNumber;
std::string s;
std::stringstream out;

out << i;
s = out.str();

Output to files:

#include <iostream>
#include <fstream>

std::ofstream myfile;
myfile.open("example.txt);
myfile << "Writing to my file ...\n";
myfile.close;

Peripherials

Serial Ports (RS232)

• Displaying all the configuration information of a serial port: setserial -a /dev/ttyS1
  Alternatively: stty -a /dev/ttyS1
• Setting the Baud rate: stty -F /dev/ttyS1 115200
• Write to the port: echo blaba > /dev/ttyS1
• Listen to the port: cat /dev/ttyS1
• Serial programming guide
• termios
• The linux hyper terminal: gtkterm

 Installation of the Printer Brother DCP-7030 in Fedora 10

1. Get the linux driver from the brother solution center (lpr + Cups)
2. Access to Cups at http://127.0.0.1:631/.
3. Go to ->Printers ->Modify Printer
4. Choose the device DCP 7030 at USB #1.
5. Load the PPD-file from /etc/share/PPD. 

Installation of the Printer Brother DCP-7030 in Ubuntu 11.10

1. Get the linux driver from the brother solution center (lpr + Cups wrapper)
2.  Install both of them with the Ubuntu Software Center.
3. Access to Cups at http://127.0.0.1:631/.
4. Go to -> Administration ->add Printer. Use the usual login for authentication.
5. Choose the device DCP 7030 at USB #1.
6. Load the PPD-file from /usr/share/cups/model.

What video card am I using?

The command lspci lists al pci (peripherial component interconnect) devices:
Vidia GeForce 8800GT.

SVN

The main resource of information for subversion is the red book. Here I list a few important commands for fast reference.

Create a new repository:

1. On the server: svnadmin create /svndir/reposname
2. From the client: svn co svn://ip_address/reposname

3. cd reposname
   mkdir trunk
   mkdir tags
   mkdir branch
   svn add *
   svn ci

Save and restore a repository:

1. Create a dump: svnadmin dump /svndir/repos/gwt > /backupDir/svn_gwt.dump
2. Create the repository: svnadmin create /svndir/repos/gwt
3. Load the repository: svnadmin load /svndir/repos/gwt < /backupDir/svn_gwt.dump

Examining the history of a repository:

•  Shows revisions 5 to 19 of a file or directory: svn log -r 5:19 file/directory_name
•  "svn diff" with no options compares the working directory with the version from the last check out.