Change Emacs home directory for all purposes

Question

I have my config files in ~/config/emacs which ~/.emacs is symlinked to.

I'm trying to figure out how to make the default "emacs root directory" $HOME in all contexts (unless overridden by a buffer-local variable), whether launching an ansi terminal, launching dired, or anything like that.

$ ls -al .emacs.d | perl -pe 's/^.*([.]emacs[.]d)/$1/'
.emacs.d -> ./config/emacs

My .emacs.d/init.el file contains the following snippet in an attempt to force emacs open stuff like dired and ansi-term in my home directory.

(cd (getenv "HOME"))

How do I change the effective root directory for ansi-term and everything else?

Here's a complete example that should reproduce the surprising behavior I'm talking about on OS X and Linux.

I have a directory ~/tmp/emacs

$ echo '(cd (getenv "HOME"))' > ~/tmp/emacs/cd.el
$ cd /tmp
$ emacs -q -l ~/tmp/emacs/cd.el

And then from inside emacs,

Launch the ansi terminal and accept the default shell

M-x ansi-term C-m C-m

print the current working directory from inside the terminal

$ pwd
/tmp

I expected working directory to be $HOME.

Answer 1

The answer is easy if you consider that default-directory (the variable returned by pwd) is always buffer local and returns the default directory of the current buffer.

With the following addition, you can watch, what's going on:

(cd (getenv "HOME"))
(message "Current dir: %s" (pwd))
(message "Current buffer: %s" (buffer-name))

Without any file loaded, the file will be executed in the context of the first buffer created and that's *scratch*. After the initialization (and the file loaded with -l belongs to this phase) a new buffer with the start message is created and this one doesn't get the default-directory from the *scratch* buffer.

tl;dr default-directory is per file and changes, when you call ansi-term (or pwd) with another buffer open. cd only changes the default-directory of the current buffer.