If no value is set then an empty line will be displayed instead. echo $JAVA_HOMEĪnd so long as the variable has a value it will be echoed out. To output the value of the environment variable from the shell, we use the echo command and prepend the variable’s name with a dollar ($) sign. export NAME=VALUEįor example, to set the environment variable for the home directory of a manual OpenJDK 11 installation, we would use something similar to the following. We give the variable a name, which is what is used to access it in shell scripts and configurations and then a value to hold whatever data is needed in the variable. To set an environment variable the export command is used. They are also used to set the important directory locations for many popular packages, such as JAVA_HOME for Java. It is not uncommon for environment specific information, such as endpoints and passwords, for example, to be stored as environment variables on a server. ![]() It is also a common means of configuring services and handling web application secrets. You will also learn how to list all environment variables and how to unset (clear) existing environment variables.Įnvironment variables are commonly used within the Bash shell. Java HotSpot(TM) 64-Bit Server VM (build 25.In this tutorial, you will learn how to set environment variables in Ubuntu, CentOS, Red Hat, basically any Linux distribution for a single user and globally for all users. Java(TM) SE Runtime Environment (build 1.8.0_291-b10) It should output the following: java version "1.8.0_291" Let the system know where JRE is installed: sudo update-alternatives -install "/usr/bin/java" "java" "/usr/local/java/jre1.8.0_291/bin/java" 1Īfter that’s done, check the installation by running: java -version To save space, delete the tarball by running: sudo rm jre-8u291-linux-圆4.tar.gz Unpack the tarball: sudo tar zxvf jre-8u291-linux-圆4.tar.gz Go into the install directory: cd /usr/local/java Move the JRE binaries into the directory: sudo mv jre-8u291-linux-圆4.tar.gz /usr/local/java InstallingĬreate a directory to install JRE in with: sudo mkdir /usr/local/java ![]() Oracle does not currently offer JRE packages for Java 11 or above from their website so, for this tutorial, we will use the Oracle HotSpot JRE version to be 8u291 (Java 8, update 291). An Oracle account is needed to download the Oracle HotSpot JRE. tar.gz (tarball) by heading over to their website. Installing Oracle HotSpot JRE Downloading the Oracle HotSpot JRE binariesĭownload JRE binaries in. In the next step we’ll install Oracle HotSpot JRE. (Although the output may change in the future as new Java versions are promoted to LTS status, or the current LTS version receives updates.) ![]() OpenJDK 64-Bit Server VM (build 11.0.11+9-Ubuntu-0ubuntu2, mixed mode) OpenJDK Runtime Environment (build 11.0.11+9-Ubuntu-0ubuntu2) It should output the following: openjdk version "11.0.11" We can check if OpenJDK JRE was properly installed by running: java -version To install the OpenJDK JRE, we run: sudo apt install default-jre (Alternatively, you may opt to use a specific Java version, using for example the openjdk-11-jre package as updates are released for that version of the Java Virtual Machine, that packages will be updated, allowing you to stick to the latest and greatest update of one specific version of the Java language.) The default-jre is an excellent choice for most situations, thanks to the outstanding track of backwards compatibility of the Java Virtual Machine. Ubuntu offers the default-jre package, which is regularly updated to ship the latest version of the current OpenJDK JRE in Long Term Support (LTS). Moreover, the non LTS versions of Java are bringing a steady stream of innovation into the language, and also see some adoption. ![]() Nowadays, Java 11 is the current Long Term Support (LTS) version, but Java 8 is still widely used. With new versions of Java released every 6 months, there are multiple versions available for use.
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