Hello guys,
I have a system where Java 1.5.x has already been installed and Tomcat 5 has already been configured. Now I want to install another application that asks for JAVA_HOME variable. When I try to echo $JAVA_HOME, it prints blank. That means JAVA_HOME is not set. But I think Java path is set in PATH environment variable since I can invoke Java compiler from root. But I want exact Java Installation Path so that I can set JAVA_HOME.
So, how can I make a search for a Java Installation Directory? For you people reference, my PATH variable gives me:

/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin

I will be thankful to you if you could help me sort out this problem.

Thanks in advance.

did you try 'which java' and/or 'whereis java'?

locate java | grep SunJava2-1.5
may find the base directory where java installed if u have findutils installed

try this:
find / -name "*java*"

That should find all your java files and folders,
remove the wildcards if you need the java binary.

Thanks guys, it worked! Actually I am new to linux so don't know these basic commands. People say that linux is great but a bit difficult for being so much Command oriented, unlike Windows which is more user friendly I STILL THINK. But learning it now.

Anyways!!! I have got some confusion, rather I want some explanation. j-ray, can u explain this command in more detail to me?

locate java | grep SunJava2-1.5


I got an error when I run this command....

Could not open database /var/lib/slocate/slocate.db

How should i tackle with this error?

Thanks again to all of you for your help.

That just means that the database listing of your files is outdated. Run "sudo updatedb" and that should be fixed. Anyways, the command "locate" looks for any instance of the search phrase (in this case: java) and prints it out. By using the pipe ("|"), you're passing what's printed out to the next command ("grep SunJava2-1.5"). grep is used to limit the output to whatever you specify (in this case: anything that has SunJava2-1.5 in the filename. Hope that helps.

Hi nilecirb,
Thanks.... for explaining in detail ;-)