Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?


I tried installing several different Java packages but all of them failed with the same error. Finally, I arrived at a working solution by running the following commands:


sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"
sudo apt-get update


Now you can successfully install Java on your system!


sudo apt-get install openjdk-6-jre-headless -y


Installing PostgreSQL 8.4.x on CentOS 5.5

• Download the PostgreSQL 8.4 repository RPM
  wget http://yum.pgsqlrpms.org/reporpms/8.4/pgdg-centos-8.4-2.noarch.rpm
• Add the repository
  rpm -ivh pgdg-centos-8.4-2.noarch.rpm
• Use yum to install PostgresSQL
  yum install -y postgresql postgresql-server
• Initialize the database
  service postgresql initdb
• Start the database
  service postgresql restart
• Automatically start database on boot
  chkconfig postgresql on

Install Ruby 1.8.7 on CentOS 5.5 (or other distributions)

yum install -y gcc zlib zlib-devel
wget ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.7-p330.tar.gz
tar xvf ruby-1.8.7-p330.tar.gz
cd ruby-1.8.7-p330
./configure --enable-pthread
make
make install


Linux sp-ubuntu 2.6.35-24-generic #42-Ubuntu SMP Thu Dec 2 01:41:57 UTC 2010 i686 GNU/Linux
Ubuntu 10.10

Welcome to Ubuntu!
* Documentation:  https://help.ubuntu.com/

78 packages can be updated.
29 updates are security updates.

Last login: Wed Feb  9 21:51:41 2011 from sp-ubuntu

If you would like to disable this message when logging in, run the following command:

touch ~/.hushlogin

And now the next time you login, you will not see any welcome message! To revert this change, simply delete the .hushlogin file in your home directory.

Find the number of files in the current and all sub-directories

find . -type f | wc -l

Find the number of files in the current directory

find . -maxdepth 1 -type f | wc -l

pdftotext -layout filename.pdf filename.txt

There are two parts to creating these files. First, is creating a single master file that contains the data that the thousands/millions files are based on. Second, splitting this master file into the total number of files that you require.

How to create the master file

1. Determine the number of files and the size of each file that you require
2. Multiply the total number of files times the size (in bytes). For example: If you want to create 10000 files that are 10 bytes each, do 10000 * 10 = 1,000,000. This represents the size of the master file that is needed.
3. To create this master file, run the command:

dd if=/dev/zero of=masterfile bs=1 count=1000000

4. The above command will create a 1 MB file called ‘masterfile’. This file contains all 0′s. If you would like it to contain random binary data, use /dev/urandom

To split the master file into thousands of pieces

1. Now that the master file is created, you can now use this to generate the desired 10,000 files that are 10 bytes each.
2. Run the command:

split -b 10 -a 10 masterfile

The -b option specifies the size in bytes of each file. The -a option defines the length of the filename of the new files +1 (-a 10 means create a 11 character long filename)

And that’s all there is to it! If you need help with any variation to this, please post it as a comment.

Examples of ‘head’ command

To print out the first 10 lines of a file
head [filename]

To print out the first 50 lines of a file
head -n 50 [filename]

To print out the first 25 bytes of a file
head -c 25 [filename]

Navigate to System –> Administration –> Printing

Then choose Server –> New –> Printer from the Printer configuration window

The New Printer wizard will be displayed. Here you can add either local or network printers. For this tutorial, we will show you how to add a Network printer. To do this, expand the Network Printer tree item and choose Windows Printer via SAMBA.

Click on the button labeled Browse… which will display a list of servers on your network. Find your corporate print server or Windows system that the printer is connected to. You should see one or more printers listed. Choose the printer and click OK.

You will now need to select the manufacturer of the printer so that the appropriate driver can be installed. Make your selection and click on the button labeled Forward.

Once you have chosen the printer manufacturer, you must select the model number. Make your selection and then click Forward. Note: If you do not see your model listed, please visit the printer manufacturer’s website to download the appropriate driver.

We’re almost done! Now you can specify the printer name and description so you can easily identify it in the future. Click Apply after doing so.

Finally, you will be greeted with a prompt to print a test page. It is a good idea to do this, so click Yes.

And there you have it. That is how you add a network printer to your Ubuntu 9.10 system!

If you are like me, you have run into this situation many many times. You run the ps command to list all the currently running processes and you see that there are multiple instances running of a certain program. You want to end all these instances but do not want to run the kill command for each one of those specifying the pid manually. Killing all instances of this program is very simple and I’ll show you how to do it using a 1 line command!

How to Kill multiple instances of a process

1. Log into the shell of your Linux/Unix box
2. If you do not know the name of the script you will like to kill, run: ps -ef This will show you a list of all the currently running processes. In the right-most column, you will find the path and filename of the script you want to end.
3. To kill all instances of this script, run the command: ps -ef | grep [search string] | awk '{print $2}' | xargs kill -9 Be sure you substitute [search string] to your own value.
4. Now run ps –ef again and all running instances of that script will be gone!

Alternative Method

If your Linux distribution has pkill installed, simply run the command:

pkill -9 -f [search string]