How Do You Create an Option to Logout for a PHP Web Page to Destroy the Session?

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Problem scenario
You have a LAMP (or LAPP) web page application.  The PHP code uses the session() functionality.  Once a user logs in successfully, he/she can browse to successive web pages.  You want to at least allow the user the opportunity to destroy the session (and terminate the authentication session).  How do you do this?

Solution
#1  Modify the .php file that you want to have the logout feature. 

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How Do You Troubleshoot the Scala Error “No such file or class on class path”?

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Problem scenario
You know Scala is installed because you use “man scala” and see the correct man page.  But when you try to find the version, you get an error.  Specifically you run this command:  scala version

You see this: “No such file or class on classpath: version.”  How do you find out what version of Scala you have installed?

Solution
Reboot the server.

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How Do You Install Scala on an Ubuntu Instance of AWS?

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Problem scenario
You want to install Scala to an Ubuntu instance of AWS.  How do you do this?

Solution

Prerequisite
Verify you have 1 GB of RAM.  Run this command:  sudo dmidecode -t 17 | grep Size

If you see 512 MB in the output, then you will not be able to get Scala installed.  You will need an AWS instance with a flavor that has 1 GB of RAM or more. 

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How Do You Log into a Linux Server in Google Cloud Platform?

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Problem scenario
You created a Linux VM in GCP.  How do you get credentials to connect to it?  What do you have to do to log in with PuTTY?

Solution
1.  Make sure the firewalls allow for the connection.  See this posting if you need to change that.
2.  In the GCP console, go to Computer Engine -VM Instances.  
3.  Go to the VM you want to connect to. 

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How Do You Install R on a RHEL Instance of AWS?

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Problem scenario
You have a RedHat Enterprise version of Linux.  You want to install the R programming language.  What do you do?

Solution
1.  Run these six commands:

sudo yum -y install wget
cd /tmp
wget ftp://rpmfind.net/linux/epel/7/x86_64/e/epel-release-7-10.noarch.rpm
sudo rpm -ivh epel-release-7-10.noarch.rpm
sudo yum-config-manager –enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional
sudo yum -y install R

2.  This is an optional step to complete these instructions. 

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How Do You Install Scala on a RHEL Instance of AWS?

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Problem scenario
You want to install Scala to a Red Hat Enterprise Linux instance of AWS.  How do you do this?

Solution
1.  Install Java:  sudo yum -y install java-1.8*

2.  Log off and log back on.

3.  Run these three commands:
curl https://bintray.com/sbt/rpm/rpm | sudo tee /etc/yum.repos.d/bintray-sbt-rpm.repo
sudo yum -y install sbt
sbt new scala/hello-world.g8

4. 

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How Do You Troubleshoot the Java Error “java.lang.Error: Properties init: Could not determine current working directory”?

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Problem scenario
You run this command:
javac -version

But you receive this error:  “Error occurred during initialization of VM java.lang.Error: Properties init: Could not determine current working directory.”

How do you solve this problem?

Solution
Log out of Linux and log back in.

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How Do You Automate a Sequence of GUI Operations to Use Sikulix as a Proof-of-Concept?

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Problem scenario
You want to try Sikulix to test it.  What do you do to implement a prototype of GUI automation of a basic procedure?

Solution
Prerequisite #1
This assumes that Sikulix has been installed.  If you do not know how, see this posting.

Prerequisite #2 (specific to this example only)
For this example we will set up an automation to open a web browser,

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