current directory

[help-gnu-emacs]

This is about unix-like environment.

Say I start emacs with a file in a certain directory, say /a/b/c:

cd ~
emacs /a/b/c/file

then, while in emacs, I open another file, say /g/d/f/file1.

It looks like after this emacs moves its "current directory" to /g/d/f. Now, if 
I start a shell script through call-process, the shell script's current 
directory is also /g/d/f, but it depends on being run somewhere in /a/b/c tree.
In fact, it looks like emacs changes its internal 'current directory' each time 
I switch to a file in a different directory, even a previously opened file.

Is there a way to prevent emacs from changing its current directory when 
opening a new file or changing between files being visited?

TIA,
/vb