Homepage: https://www.gnu.org/software/emacs
Author: Peter Breton
Directory Tracking by watching the prompt
Shell directory tracking by watching the prompt.
This is yet another attempt at a directory-tracking package for
Emacs shell-mode. However, this package makes one strong assumption:
that you can customize your shell's prompt to contain the
current working directory. Most shells do support this, including
almost every type of Bourne and C shell on Unix, the native shells on
Windows95 (COMMAND.COM) and Windows NT (CMD.EXE), and most 3rd party
Windows shells. If you cannot do this, or do not wish to, this package
will be useless to you.
Installation:
1) Set your shell's prompt to contain the current working directory.
You may need to consult your shell's documentation to find out how to
do this.
Note that directory tracking is done by matching regular expressions,
therefore it is *VERY IMPORTANT* for your prompt to be easily
distinguishable from other output. If your prompt regexp is too general,
you will see error messages from the dirtrack filter as it attempts to cd
to non-existent directories.
2) Set the variable `dirtrack-list' to an appropriate value. This
should be a list of two elements: the first is a regular expression
which matches your prompt up to and including the pathname part.
The second is a number which tells which regular expression group to
match to extract only the pathname. If you use a multi-line prompt,
add t as a third element. Note that some of the functions in
'comint.el' assume a single-line prompt (eg, comint-bol).
Determining this information may take some experimentation. Using
`dirtrack-debug-mode' may help; it causes the directory-tracking
filter to log messages to the buffer `dirtrack-debug-buffer'.
3) Activate `dirtrack-mode'. You may wish to turn ordinary shell
tracking off by calling `shell-dirtrack-mode'.
Examples:
1) On Windows NT, my prompt is set to emacs$S$P$G.
'dirtrack-list' is set to (list "^emacs \\([a-zA-Z]:.*\\)>" 1)
2) On Solaris running bash, my prompt is set like this:
PS1="\w\012emacs@\h(\!) [\t]% "
'dirtrack-list' is set to (list "^\\([/~].*\\)\nemacs@[^%]+% *" 1 t)
I'd appreciate other examples from people who use this package.
Here's one from Stephen Eglen:
Running under tcsh:
(setq-default dirtrack-list '("^%E \\([^ ]+\\)" 1))
It might be worth mentioning in your file that Emacs sources start up
files of the form: ~/.emacs_ where is the name of the
shell. So for example, I have the following in ~/.emacs_tcsh:
set prompt = "%%E %~ %h% "
This produces a prompt of the form:
%E /var/spool 10%
This saves me from having to use the %E prefix in other non-emacs
shells.
A final note:
I run LOTS of shell buffers through Emacs, sometimes as different users
(eg, when logged in as myself, I'll run a root shell in the same Emacs).
If you do this, and the shell prompt contains a ~, Emacs will interpret
this relative to the user which owns the Emacs process, not the user
who owns the shell buffer. This may cause dirtrack to behave strangely
(typically it reports that it is unable to cd to a directory
with a ~ in it).
The same behavior can occur if you use dirtrack with remote filesystems
(using telnet, rlogin, etc) as Emacs will be checking the local
filesystem, not the remote one. This problem is not specific to dirtrack,
but also affects file completion, etc.