How to Fetch Java Version Using Single Line Command in Linux

How to fetch Java version using single line command in Linux

1. Redirect stderr to stdout.
2. Get first line

3. Filter the version number.

   java -version 2>&1 | head -n 1 | awk -F '"' '{print $2}'
   

Correct way to check Java version from BASH script

Perhaps something like:

if type -p java; then
    echo found java executable in PATH
    _java=java
elif [[ -n "$JAVA_HOME" ]] && [[ -x "$JAVA_HOME/bin/java" ]];  then
    echo found java executable in JAVA_HOME     
    _java="$JAVA_HOME/bin/java"
else
    echo "no java"
fi

if [[ "$_java" ]]; then
    version=$("$_java" -version 2>&1 | awk -F '"' '/version/ {print $2}')
    echo version "$version"
    if [[ "$version" > "1.5" ]]; then
        echo version is more than 1.5
    else         
        echo version is less than 1.5
    fi
fi

Running a Specific Version of Java on the Linux Command Line

Given this is not caused by a permissions issue, it could be the result of a missing 32 bit runtime which is detailed here

How to run an application on a specific Java version?

You can run java with the absolute path to the installation

This would be your default /usr/bin/java installation

java -version

To change it, use the absolute path

/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java -version

If you're not running the java command directly, try setting the JAVA_HOME variable:

JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/jre/" pdfsam

How to check java version at linux (RedHat6)

To answer your question directly, you can use

rpm -qi java

OR

yum info "java"

For future Referenecs . You can try any of these commands.

rpm -qi "package_name_without_quotes"

It gives information of installed package. To display information about one or more packages (glob expressions are valid here as well), use the following command :

yum info "package_name_without quotes"

OR

yum list "package_name_without_quotes"

OR

yum --showduplicates list "package_name_without_quotes"

The yum info package_name command is similar to the rpm -q --info package_name command, but provides as additional information the ID of the Yum repository the RPM package is found in.

You can also query the Yum database for alternative and useful information about a package by using the following command :

yumdb info "package_name_without_quotes"

This command provides additional information about a package, including the check sum of the package (and algorithm used to produce it, such as SHA-256), the command given on the command line that was invoked to install the package (if any), and the reason that the package is installed on the system.

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