changing an environment variable like PATH forever [duplicate]

Question

Possible Duplicate:
How do I set a user environment variable? (permanently, not session)

to change the amount of PATH variable , I use : export PATH=...
but when I close the terminal, the amount of PATH becomes what it was at the first.

I want to save the changes , so that the amount will be what I want after closing the terminal or logging out.

how can I do this work?
I use Fedora 17, kernel : 3.4.3
(sorry for my weak english)

Answer 1

make the setting persistent:

add this line: export PATH=/path/to/dir in your ~/.bashrc if using bash, or ~/.zshrc for zsh:

$ vim ~/.bashrc

export PATH=$PATH:/path/to/dir

:wq

or:

$ echo "export PATH=$PATH:/path/to/dir" >> ~/.bashrc

LATER EDIT!

Answer 2

Each time you execute a bash (non-login) shell instance, it reads and executes the .bashrc file in your home directory. Login shells, on the other hand, do that for .profile file, located in your home directory. You can find the difference between login and non-login shells by reading the bash manual.

In your case, open your ~/.bashrc and set there the variable that you want. For example:

PATH="/some/new/path:$PATH"

Save it, and reload it:

$ source ~/.bashrc