Creating a variable to a directory that persists until deletion

Question

I'm currently using bash on Ubuntu, and I work a lot with a directory saved at /home/me/path/to/project_dir. It is a nuisance to change to the directory every time I open bash. So I'd like to save the path to a variable, say projdir, so that I can just do cd projdir. If my working directory changes, I should be able to change the path by overwriting the variable. I want to be able to update the variable easily, preferably with one command, without messing with .bashrc.

One important thing is that this variable should persist even if I restart bash. How do I do this? I'd still like to see my home directory when I start up bash, so changing the default starting directory to project_dir is not an option.

Answer 1

Have a look at CDPATH in man bash maybe that is already enough.

Otherwise define some alias in .bashrc. I would suggest:

alias setp='pwd >~/.projectdir'
alias gop='cd $(cat ~/.projectdir)'

Answer 2

echo 'PROJDIR="/home/me/path/to/project_dir"' > ~/.projdir
# put the next in e.g. .bashrc
projdir () {
  . ~/.projdir
  cd "$PROJDIR"
}
# change into directory simply by
projdir
# if dir changes just repeat
echo 'PROJDIR="/home/me/path/to/other_project_dir"' > ~/.projdir
# and instantly this works from all shells / consoles:
projdir

Answer 3

Make a symbolic link in your home directory.

ln -s path/to/project_dir ~/p

Run cd p to switch to that project directory.

That's a bit of a cumbersome approach though. You could run one shell and switch to the desired directories, then start other shells from it, by running xterm & disown (replace xterm by whatever terminal emulator you prefer).