How to set `JAVA_HOME` and where is whereis on Solaris?

To set the JAVA_HOME environment variable you first need to find where your Java installation is located and then set it somehow.

How to find it

$ whereis java /usr/bin/java $ ls -l /usr/bin/java lrwxrwxrwx ...
/usr/bin/java -> ../java/bin/java

First command figures out where the java command is located. We then use ls -l and finds that /usr/bin/java actually points to ../java/bin/java. As an absolute path, that would be /usr/java/bin/java. This means our JAVA_HOME should be set to /usr/java.

(I have assumed that Java actually is installed. If it isn't, you need to do that first)

But where is whereis?

The above example is how it normally goes for me on for example Ubuntu (although the directory you get might be different). However, this is what happened when I did it on a machine running SunOS 5.10:

$ whereis java -bash: whereis: command not found

Turns out that command doesn't exist on Solaris. Luckily we can use a command called which instead, which gives you the same result.

$ which java /usr/bin/java

But I want to use whereis!

Well, turns out you can! Apparently the command actually does exist. It's just not in your path by default. This command (and some others) can be found in /usr/ucb, so we just need to add that to our PATH and we can use it like normal.

How to set it

There are various ways of doing this, and in my case the simplest way was to add the lines below to a file called ~/.profile.

JAVA_HOME=/usr/java
export JAVA_HOME

PATH=$PATH:/usr/ucb
export PATH

The last two lines shows how to add /usr/ucb to your path, which you can skip if you don't feel a great need to use whereis later.