Correct way to check Javac version in BASH script

Question

I am trying to get the javac version in a bash script (intended for apks manipulation and builds).

I found a way to get the java version which may be similar but not the same (it does not work for javac).

P.S.: Currently working on OS X but should also work on Linux.

EDIT: PS: Some environments may not have javac in the PATH

Thanks!

`javac -version` seems to work just fine when `javac` is in the `PATH`. What is your specific problem? — Aaron, Jun 28 '16 at 14:02
we can't help you fix your code if you don't include it in your Q. Good luck. — shellter, Jun 28 '16 at 14:38

score 2 · Accepted Answer · answered Jun 29 '16 at 14:28

Try this function that supports both cases, when javac is or is not in PATH variable

showJavacVersion() 
{
    x="h"
    {
        x=$(type -p javac)
    } >&-
    if [ -n "$x" ]; then
        _javac=javac
    elif [[ -n "$JAVA_HOME" ]] && [[ -x "$JAVA_HOME/bin/javac" ]];  then
        _javac="$JAVA_HOME/bin/javac"
    fi
    if [[ "$_javac" ]]; then
        version=$("$_javac" -version 2>&1 | awk -F ' ' '/javac/ {print $2}')
        echo $version
    else
        echo javac not found
    fi
}

Simply call it this way

showJavacVersion

Hope it helps!

The JAVA_HOME thing did the trick. It happened because I needed to run this in environments with no "install" but copied SDKs. — DNax, Jun 29 '16 at 14:46

score 0 · Answer 2 · answered Jun 28 '16 at 14:24

0

If javac in the PATH:

jc_ver="$(javac -version 2>&1| grep -o '[0-9_.]*$')"
echo "$jc_ver"

Or using cut:

jc_ver="$(javac -version 2>&1| cut -d ' ' -f2)"

answered Jun 28 '16 at 14:24

Jahid

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Also using awk jc_ver=$(javac -version 2>&1 | awk -F ' ' '/javac/ {print $2}') – gabocalero Jun 29 '16 at 14:43

Correct way to check Javac version in BASH script

2 Answers2