I want to fetch the Java version in Linux in a single command.
I am new to awk so I am trying something like
java -version|awk '{print$3}'
But that does not return the version. How would I fetch the 1.6.0_21 from the below Java version output?
java version "1.6.0_21"
Java(TM) SE Runtime Environment (build 1.6.0_21-b06)
Java HotSpot(TM) 64-Bit Server VM (build 17.0-b16, mixed mode)
Filter the version number.
java -version 2>&1 | head -n 1 | awk -F '"' '{print $2}'
AIX machine saying awk: can't open {print$2}. What could be the problem?
java -version 2>&1 | head -n 1 | awk -F '"' '{print $2}' | awk -F '.' '{print $2}' if you just want the major version number.
JAVA_TOOL_OPTIONS in in the environment, the version will not be on the first line, breaking this command.This is a slight variation, but PJW's solution didn't quite work for me:
java -version 2>&1 | head -n 1 | cut -d'"' -f2
just cut the string on the delimiter " (double quotes) and get the second field.
I'd suggest using grep -i version to make sure you get the right line containing the version string. If you have the environment variable JAVA_OPTIONS set, openjdk will print the java options before printing the version information. This version returns 1.6, 1.7 etc.
java -version 2>&1 | grep -i version | cut -d'"' -f2 | cut -d'.' -f1-2
Since (at least on my linux system) the version string looks like "1.8.0_45":
#!/bin/bash
function checkJavaVers {
for token in $(java -version 2>&1)
do
if [[ $token =~ \"([[:digit:]])\.([[:digit:]])\.(.*)\" ]]
then
export JAVA_MAJOR=${BASH_REMATCH[1]}
export JAVA_MINOR=${BASH_REMATCH[2]}
export JAVA_BUILD=${BASH_REMATCH[3]}
return 0
fi
done
return 1
}
#test
checkJavaVers || { echo "check failed" ; exit; }
echo "$JAVA_MAJOR $JAVA_MINOR $JAVA_BUILD"
~
if [[ $token =~ "\"([[:digit:]])\.([[:digit:]])\.(.*)\"" ]]
You can use --version and in that case it's not required to redirect to stdout
java --version | head -1 | cut -f2 -d' '
From java help
-version print product version to the error stream and exit
--version print product version to the output stream and exit
Here's my variation (with thanks/acknowledgements to many answers prior to this). My goal is to produce a "Major Version" in line with JEP 223. Assumption are made; I don't know if it works across the board for all released (or to be released) versions of java.
java -version 2>&1 | fgrep -i version | cut -d'"' -f2 | sed -e 's/^1\./1\%/' -e 's/\..*//' -e 's/%/./'
| Version | Results |
|---|---|
| 1.6.0_65 | 1.6 |
| 1.8.0_282 | 1.8 |
| 11.0.10 | 11 |
| 15.0.2 | 15 |
This way works for me.
# java -version 2>&1|awk '/version/ {gsub("\"","") ; print $NF}'
1.8.0_171
java -version 2>&1 | head -1 | awk -F '_|"' '{print $2}'
Output
1.8.0
Or
java -version 2>&1 | head -1 | awk -F '_|"' '{print $2}' | cut -c 1-3
Output
1.8
Getting only the "major" build #:
java -version 2>&1 | head -n 1 | awk -F'["_.]' '{print $3}'
