Install Jupyter Notebook without Anaconda

I love the Jupyter Notebook for working in Python.  However, I have been fairly disappointed with the performance (start-up time, cpu and memory utilization) of Anaconda on my Window’s computers.  I have also wanted to use Jupyter on a Dell laptop running Ubuntu Linux with limited memory and disk space, without the bloat of Anaconda.

Installing Jupyter without Anaconda is actually fairly simple.  See: Installing Jupyter with pip.  It’s so easy that I don’t see why they put the “strongly recommend” using Anaconda to run Juypter in bold.   Since pip is installed already on the latest versions of Python, you don’t even have to go out looking for a separate script to install or update it.  It works like a charm.

Deploy Node.js to Fedora 18

Per github wiki for node.js, Fedora 19 will have node.js included.  However, to obtain node.js in Fedora 18, do the following:

sudo yum --enablerepo=updates-testing install nodejs npm

 

Grep through a unix directory with a long list of files

Sometimes when attempting to grep through the files in a directory, there are so many files in the directory that grep returns an error indicating the argument list is too long.  Fix this by using xargs.

find ./ -print | xargs grep -l <your_string>

Count number of files in a unix directory

ls -1 | wc -l

Add/view/delete an entry to iptables to enable Apache/VNCServer/FTP, etc.

The default CentOS 5.6 firewall configuration does not allow Apache httpd traffic on port 80.  In order to open the port for utilization, a change must be made to the firewall configuration.

iptables -I INPUT -p tcp -m tcp ––dport 80 -j ACCEPT

To open a hole for VNCServer (running on display 20):

iptables -I INPUT -p tcp -m tcp ––dport 5920 -j ACCEPT

To open a hole for VNCServer (running on display 20) web base interface:

iptables -I INPUT -p tcp -m tcp ––dport 5820 -j ACCEPT

To display the openings you’ve created in your firewall:

iptables -L INPUT -n ––line-numbers

To remove a line entry from your iptables file (for example, entry #3):

iptables -D INPUT 3

Notes:

There are two dashes in front of parameters such as “––line-numbers” and “––dport.”

The iptables service must be saved, and restarted before changes take effect.

service iptables save

service iptables restart

manually add new user to Red Hat/Fedora/CentOS

To manually add a new user to a  Red Hat/Fedora/CentOS intall which is utilizing shadow passwords:

As root

• cp /etc/passwd /etc/passwd.bak (make a back-up copy of your password file)
• cp /etc/shadow /etc/shadow.bak (make a back-up copy of your shadow password file)
• cp /etc/group /etc/group.bak (make a back-up copy of your group file)
• vipw  (to open passwd file in vi)
• <shift> g  (to get to end of file)
• a (append at end of cursor)
• user01:x:501:501:User 01:/home/user01:/bin/bash  (add the new user)
• :wq  (write file and quit vi)
• A prompt will indicate that you are using shadow passwords, and do you want to edit the /etc/shadow now.  Answer: n
• vi /etc/group  (to open group file in vi)
• <shift> g  (to get to end of file)
• a (append at end of cursor)
• user01:x:501:user01 <enter>
• admins:x:502:user01 (create a new group called admins and put user01 into it)
• :wq  (write file and quit vi)
• pwconv  (add the new entry from your passwd file into shadow password file)
• passwd user01  (set the new user password)
• (prompted twice for new user password)
• mkdir /home/user01
• cp /etc/skel/.* /home/user01 (copy all files from skel to new user home directory)
• cp -r /etc/skel/.kde /home/user01
• cp -r /etc/skel/.mozilla /home/user01
• chown -R user01:user01 /home/user01  (Change the owner of user01 home directory to user01)
• visudo -f /etc/sudoers
• After root   ALL=(ALL)    ALL add new line and:  %admins   ALL=(ALL)    NOPASSWD: ALL  (this allows members of admins group to sudo as root, without a password.)

Edit sudoers file in Redhat/Fedora/CentOS

To allow certain users to act as root (su -, or sudo), you must add them to the sudoers file (/etc/sudoers).

The sudoers file must be edited using the visudo command.  See the sudo webpage.

As root:

visudo -f /etc/sudoers

Edit the file to add the correct permissions.  In this case, give members of the group “adm” permission to do just about everything.

%adm     ALL=(ALL)     NOPASSWD: ALL

Save the changes using “:wq”

 

 

Default WebLogic KeyStore Password/PassPhrase

WebLogic comes with default keystores for client and server security enabled.  However, I have found it problematic to find and remember the passwords/passphrases for the default keystores.

Property	Value
Trust store location	%ORACLE_HOME%/weblogic/wlserver_10.3/ server/lib/DemoTrust.jks
Trust store password	DemoTrustKeyStorePassPhrase
Key store location	%ORACLE_HOME%/weblogic/wlserver_10.3/ server/lib/DemoIdentity.jks
Key store password	DemoIdentityKeyStorePassPhrase
Private key password	DemoIdentityPassPhrase

Property	Value
Trust store location	%ORACLE_HOME%/weblogic/wlserver_10.3/ server/lib/DemoTrust.jks
Trust store password	DemoTrustKeyStorePassPhrase
Key store location	%ORACLE_HOME%/weblogic/wlserver_10.3/ server/lib/DemoIdentity.jks
Key store password	DemoIdentityKeyStorePassPhrase
Private key password	DemoIdentityPassPhrase

Keytool commands

Useful keytool commands for checking a certificate from sslshopper.com.

Java Keytool Commands for Checking

If you need to check the information within a certificate, or Java keystore, use these commands.

• Check a stand-alone certificatekeytool -printcert -v -file mydomain.crt
• Check which certificates are in a Java keystorekeytool -list -v -keystore keystore.jks
• Check a particular keystore entry using an aliaskeytool -list -v -keystore keystore.jks -alias mydomain