system wide locations

[ishan3243]

what are system wide locations in linux?
is there only one such location? can it be changed?

[Irithori]

Hi and welcome

there are multiple type of file.
Binaries, configfiles, logfiles, etc
Each do have well defined system wide locations, and some additionally do have user local ones.

You didnt specify, which type you need. So for a comprehensive overview, look here:
Filesystem Hierarchy Standard

[ishan3243]

actually i was trying to install java on ubuntu 12.10 from this link
java.com/en/download/help/linux_x64_install.xml

there is a note about root access on the page.....can you explain me what its saying?

[Irithori]

root is a privileged user.
This account has control over all the aspects of a system, not just file access.

As you are using ubuntu, this guide is more appropiate
https://help.ubuntu.com/community/Java

[ishan3243]

so where should i install java so that "java -version" will work?

[Irithori]

Just follow the documentation I linked.

[ishan3243]

sudo update-alternatives --config java
this gives no alternatives.

[Rubberman]

Depending upon the variety of java you are installing, it can be installed into /etc/alternatives (openjdk) or /usr/java (sun/oracle java). If you installed sun/oracle java, then the last version you installed will have a link as /usr/java/latest, and /usr/bin/java will have been configured to point to the bin/java executable under that. You can have multiple versions of java installed, but only one will be the default. Personally, I very much dislike the alternatives way of doing things, but have to deal with it given we do a LOT of java programming where I work. Thankfully, most of my work is in C++...