How can I keep dired in sync with a shell buffer?

Question

I have some work that requires I move around between various sub-directories. Thus, the easiest way I have found to do that is to use dired. I also have to view some files (plain text or code), so another benefit is I can just hit RET on the filename to do that. However, I sometimes need to run shell commands on these files. Before I used Emacs, I would just use Bash (navigating with pushd and popd, which is less convenient than dired), so this allowed me to run the commands I needed.

How can I easily combine the best of both methods? I see a couple options:

1. Somehow keep a shell buffer in sync with the dired buffer. (Maybe somehow trigger pushd/popd/cd?)
2. Set up some keyboard shortcuts for the shell buffer, to simulate movement and file viewing (the latter especially seems more difficult).
3. Something else?

Note that I would prefer not to call shell-command (M-!) every time, because it is harder to execute multiple commands in quick succession, and interact with the command output, in addition to having a less-than-convenient default keybinding.

Answer 1

You can modify dired-after-readin-hook to send an appropriate command to your shell buffer. The following code creates a shell called dired-synced-shell if one doesn't already exist, and every time you change a directory in dired, runs a cd on the shell running in buffer dired-synced-shell.

(add-hook 'dired-after-readin-hook (lambda()
                     (unless (get-buffer "dired-synced-shell") (shell "dired-synced-shell"))
                     (process-send-string (get-buffer "dired-synced-shell") (format "cd %s\n" default-directory))
                     (message "Switched to new directory")))

OP Edit: Here are two issues I found, with workarounds:

1. This doesn't work for switching to a dired buffer that already exists. Workaround: press g to refresh the buffer.

2. This causes my shell prompt to get smashed together with the previous, as it might if the output of the previous command didn't contain a newline. (E.g. if my shell prompt is [scott@local]$, then on switching to a new dired buffer, I would see [scott@local]$ [scott@local]$. Workaround: add a newline to the beginning of my shell prompt.