Run an Emacs command for another project (
Commands that operate on project files (see Project Commands That Operate on Files) will conveniently prompt you for a project directory when
no project is current. When you are inside some project, but you want
to operate on a different project, use the C-x p p command
project-switch-project). This command prompts you to choose a
directory among known project roots, and then displays the menu of
available commands to operate on the project you choose. The variable
project-switch-commands controls which commands are available
in the menu, and which key invokes each command.
project-list-file names the file in which Emacs
records the list of known projects. It defaults to the file
user-emacs-directory (see How Emacs Finds Your Init File).