Emacs + tramp + plink - emacs

I'm trying to get emacs tramp running under Windows XP to work over putty plink on an Amazon EC2 instance. The documentation for doing this is sparse. I can find partial documentation, but none that addresses all the steps required to get this working.
Can anyone provide a walk through, or a pointer to a walk through?

(add-to-list 'load-path
(expand-file-name "C:/tools/emacsw32/emacs/lisp/tramp/lisp"))
(require 'tramp)
;(setq tramp-chunksize "500")
(setq tramp-default-method "plink")
from my dot-emacs file. If I find more notes, I shall add them here.

I'll assume you have a GNU/Linux server you want to access, a username and a .ppk file. Also, Emacs 24.4+.
First set up server in PuTTY Configuration
In section Session, specify Host Name, for example username#server.
Go to section Connection > SSH > Auth and Browse for your "Private key file for authentication".
Back to section Session, name your Saved Sessions, for example putty-test, and click Save button.
Check your connection by clicking the Open button. If it works, you can close these now.
Next, head to your Emacs.
Make sure Emacs knows where your plink.exe is. One way is to just inform Emacs directly in your .emacs, for instance I have at the moment,
(setenv "PATH" (concat "c:/Users/Brady/Documents/putty/;" (getenv "PATH")))
Simply type C-x C-f //plink:putty-test:/ RET. Wait a moment while it connects, and window will open to dired buffer on the remote ~/ directory.

This worked for me on :
Windows 10
Emacs found at https://sourceforge.net/projects/emacsbinw64/files/release/.
cygwin64
Putty.
https://github.com/d5884/fakecygpty
The changes from the original tramp-sh.el is
for cygwin, use fakecygpty with ssh and change the prompt to ##
for plink, remove -ssh option
I have also renamed these method with w to differentiate it.
(when (string-equal system-type "windows-nt")
(add-to-list 'tramp-methods
`("sshw"
(tramp-login-program "fakecygpty ssh")
;; ("%h") must be a single element, see `tramp-compute-multi-hops'.
(tramp-login-args (("-l" "%u" "-o \"StrictHostKeyChecking=no\"") ("-P" "%p") ("-t")
("%h") ("\"")
(,(format
"env 'TERM=%s' 'PROMPT_COMMAND=' 'PS1=%s'"
tramp-terminal-type
"##"))
("/bin/sh") ("\"")))
(tramp-remote-shell "/bin/sh")
(tramp-remote-shell-login ("-l"))
(tramp-remote-shell-args ("-c"))
(tramp-default-port 22))
)
(add-to-list 'tramp-methods
`("plinkw"
(tramp-login-program "plink")
;; ("%h") must be a single element, see `tramp-compute-multi-hops'.
(tramp-login-args (("-l" "%u") ("-P" "%p") ("-t")
("%h") ("\"")
(,(format
"env 'TERM=%s' 'PROMPT_COMMAND=' 'PS1=%s'"
tramp-terminal-type
"$"))
("/bin/sh") ("\"")))
(tramp-remote-shell "/bin/sh")
(tramp-remote-shell-login ("-l"))
(tramp-remote-shell-args ("-c"))
(tramp-default-port 22))
)
)

Related

Locate and open remote files

In emacs, the locate command provides a way to run unix's locate and open files on the local filesystem.
I'm using TRAMP to access remote files - is it possible to use emacs' locate to find and open remote files?
Likely, it is not possible. locate uses call-process, which does not run remote processes.
I don't know if you can use Emacs's locate function with TRAMP per se, but you could connect to a host remotely and run locate on that system via M-x shell or M-x eshell. I have some wrapper functions which make this task easier (although I mostly got them from elsewhere):
(defun remote-eshell (host)
(interactive "sHost: ")
(let ((default-directory (concat "/ssh:" (format "%s:" host))))
(eshell host)))
(defun remote-shell (host)
(interactive "sHost: ")
(let ((default-directory (concat "/ssh:" (format "%s:" host))))
(shell)))
After locating the desired files on the remote host, you can then open them via TRAMP using C-x C-f /ssh:remotehost
Also, if you're connecting via TRAMP to a remote host, you should make sure that said host is not sending any weird prompts since TRAMP doesn't handle those well. See more about that here.

eshell TRAMP find remote file with relative path (or at least less than the full Tramp path)?

I love eshell's TRAMP integration. With it I can do cd /ssh:foo:/etc to
ssh into a remote machine and visit its /etc/ directory. I can also do
find-file motd to open this file in my local emacs. However, what if I need to use sudo to change the file? I know I can give the
full path, like so:
find-file /sudo:foo:/etc/motd
but is there a way to open the file via TRAMPs sudo support, without having to type the full path?
I managed to came up with the following eshell alias that works for me:
alias sff 'find-file "${pwd}/$1"(:s/ssh/sudo/)'
It should be fairly obvious what it does. It prepends the working directory
path, but with the string ssh replaced by sudo. Thus it only works for
remote files accessed over ssh. I rarely edit files using sudo locally, so
that's not a problem for me. However, we can make it work for local files too, at the cost of complexity:
alias sff 'find-file "${pwd}/$1"(:s,^,/sudo::,:s,::/ssh:,:,)'
That is, prepend /sudo:: (which is how to sudo for local files) and
subsequently replace any ocurrence of ::/ssh: with :. (I would have just removed :/ssh:, but eshell's :s/// construct didn't accept an empty
replacement.)
I found an alternative answer that works very well over at EmacsWiki.
Using that you'd still open the file with find-file as usual, but then
invoke M-x sudo-edit-current-file (shown below) to re-open the file as root
using Tramp. I think this is a very elegant solution, because often I
initially just want to look at a file, then later find that I need to edit it.
Here's the function, in case it disappears from the page above:
(set-default 'tramp-default-proxies-alist (quote ((".*" "\\`root\\'" "/ssh:%h:"))))
(require 'tramp)
(defun sudo-edit-current-file ()
(interactive)
(let ((position (point)))
(find-alternate-file
(if (file-remote-p (buffer-file-name))
(let ((vec (tramp-dissect-file-name (buffer-file-name))))
(tramp-make-tramp-file-name
"sudo"
(tramp-file-name-user vec)
(tramp-file-name-host vec)
(tramp-file-name-localname vec)))
(concat "/sudo:root#localhost:" (buffer-file-name))))
(goto-char position)))

Emacs: disable Ido completion in Tramp mode

I often use ido for auto-completion and tramp to access remote server via ssh. My .emacs includes the following lines:
(require 'tramp)
(setq tramp-default-method "ssh")
(ido-mode 1)
(setq ido-enable-flex-matching t)
(setq ido-everywhere t)
I want to disable Ido completion, when i'm browsing contents of remote server. Note that variable ido-enable-tramp-completion has nothing to do with my problem. Consider line /root#site.com#1234:/var/www/file.txt. I need Ido not to deduct the part after the colon (remote file path), i don't care about the part before the colon. I use ssh, and Ido makes Emacs lag for a few seconds every time i run ido-find-file, and when ssh timeout is over, Tramp tries to reconnect, asks me for a password and so on. This behavior is undesirable.
Emacs version - 24.0.94.1
Edit (20.03.12): After contact with Ido author I tried to change the ido-file-name-all-completions-1 to the following:
(defun ido-file-name-all-completions-1 (dir)
(cond
((ido-nonreadable-directory-p dir) '())
;; do not check (ido-directory-too-big-p dir) here.
;; Caller must have done that if necessary.
((and ido-enable-tramp-completion
(or (fboundp 'tramp-completion-mode-p)
(require 'tramp nil t))
(string-match "\\`/[^/]+[:#]\\'" dir))
;; TRAMP RELATED CODE DELETED
nil)
(t
(file-name-all-completions "" dir))))
No success. I then changed regex to
"\\`/[^/]+[:#]"
and it worked - Ido was disabled, when minibuffer contained that match. However as Ido couldn't see files on a remote server, it started calling ido-make-merged-file-list to search for files in other directories every time i enter something. This made working with Ido on remote servers even more pain.
I also tried setting up variables ido-slow-ftp-hosts and ido-slow-ftp-host-regexps to /root#site.com#1234, didn't help.
If you enter C-x C-f again you temporally disable ido-find and fall back to the default find-file.
For more information C-h f ido-find-file RET
To do this every time ido found a colon, I guess you have to write your own function for that.

Dired copy asynchronously

Is there a way to modify/tell dired to copy files asynchronously? If you mark multiple files in dired and then use 'C' to copy them, emacs locks up until every file is copied. I instead want this copy to be started, and for me to continue editing as it goes on in the background. Is there a way to get this behaviour?
EDIT: Actually, C calls 'dired-do-copy' in dired-aux, not in dired itself. Sorry for any confusion.
I think emacs is mostly limited to a single thread - so this may not be directly possible through standard dired commands such as 'C' copy.
However, there is a dired command "dired-do-shell-command" which calls out to a shell to do the work in the background. If you select the files you want to copy and then use key '!' (this runs dired-do-shell-command) then type 'cp ? [destination]' (possibly can use 'copy' if you are on windows). I haven't tested this - so see help on "dired-do-shell-command" for full details.
See also the Emacs function dired-do-async-shell-command.
For an even more generic solution see https://github.com/jwiegley/emacs-async with which you also can evaluate arbitrary Emacs Lisp code through call to a separate Emacs process (which of course incurs a bit of extra latency). More specifically regard file operations see the file dired-async.el in this repo.
Also note that there is work on threading in Emacs under the working name Concurrent Emacs but it's not there yet. See http://www.emacswiki.org/emacs/ConcurrentEmacs for details.
I found this answer quite helpful: https://emacs.stackexchange.com/a/13802/10761. Reading that answer shows that you can make it so that dired will copy with the scp method instead of the ssh method (the latter initially encodes the file with gzip and that can be quite slow). The scp method will only copy with the scp program when the file is larger than tramp-copy-size-limit (which is 10240 by default). Using this scp method in conjunction with dired-async-mode is very nice, as it will not only copy quickly with scp, but it will also do it asynchronously and out of your way.
Also, I think this is useful: https://oremacs.com/2016/02/24/dired-rsync/. It provides this snippet of code to use rsync to copy files in dired:
;;;###autoload
(defun ora-dired-rsync (dest)
(interactive
(list
(expand-file-name
(read-file-name
"Rsync to:"
(dired-dwim-target-directory)))))
;; store all selected files into "files" list
(let ((files (dired-get-marked-files
nil current-prefix-arg))
;; the rsync command
(tmtxt/rsync-command
"rsync -arvz --progress "))
;; add all selected file names as arguments
;; to the rsync command
(dolist (file files)
(setq tmtxt/rsync-command
(concat tmtxt/rsync-command
(shell-quote-argument file)
" ")))
;; append the destination
(setq tmtxt/rsync-command
(concat tmtxt/rsync-command
(shell-quote-argument dest)))
;; run the async shell command
(async-shell-command tmtxt/rsync-command "*rsync*")
;; finally, switch to that window
(other-window 1)))
(define-key dired-mode-map "Y" 'ora-dired-rsync)

Open a file with su/sudo inside Emacs

Suppose I want to open a file in an existing Emacs session using su or sudo, without dropping down to a shell and doing sudoedit or sudo emacs. One way to do this is
C-x C-f /sudo::/path/to/file
but this requires an expensive round-trip through SSH. Is there a more direct way?
[EDIT] #JBB is right. I want to be able to invoke su/sudo to save as well as open. It would be OK (but not ideal) to re-authorize when saving. What I'm looking for is variations of find-file and save-buffer that can be "piped" through su/sudo.
The nice thing about Tramp is that you only pay for that round-trip to SSH when you open the first file. Sudo then caches your credentials, and Emacs saves a handle, so that subsequent sudo-opened files take much less time.
I haven't found the extra time it takes to save burdening, either. It's fast enough, IMO.
Tramp does not round-trip sudo via SSH, it uses a subshell. See the manual: https://www.gnu.org/software/tramp/#Inline-methods
Therefore, I recommend that you stick with TRAMP.
If you use helm, helm-find-files supports opening a file as root with C-c r.
Not really an answer to the original question, but here's a helper function to make doing the tramp/sudo route a bit easier:
(defun sudo-find-file (file-name)
"Like find file, but opens the file as root."
(interactive "FSudo Find File: ")
(let ((tramp-file-name (concat "/sudo::" (expand-file-name file-name))))
(find-file tramp-file-name)))
Your example doesn't start ssh at all, at least not with my version of TRAMP ("2.1.13-pre"). Both find-file and save-buffer work great.
At least for saving, a sudo-save package was written exactly for that kind of problem.
I recommend you to use advising commands. Put this function in your ~/.emacs
(defadvice ido-find-file (after find-file-sudo activate)
"Find file as root if necessary."
(unless (and buffer-file-name
(file-writable-p buffer-file-name))
(find-alternate-file (concat "/sudo:root#localhost:" buffer-file-name))))
(works only locally. Need to be updated to work correctly via tramp)
A little bit extended Burton's answer:
(defun sudo-find-file (file-name)
"Like find file, but opens the file as root."
(interactive "FSudo Find File: ")
(let ((tramp-file-name (concat "/sudo::" (expand-file-name file-name))))
(find-file tramp-file-name)))
(add-hook 'dired-mode-hook
(lambda ()
;; open current file as sudo
(local-set-key (kbd "C-x <M-S-return>") (lambda()
(interactive)
(message "!!! SUDO opening %s" (dired-file-name-at-point))
(sudo-find-file (dired-file-name-at-point))
))
)
)
Ugh. Perhaps you could open a shell in Emacs and exec sudo emacs.
The problem is that you presumably don't just want to open the file. You want to be able to save it later. Thus you need your root privs to persist, not just exist for opening the file.
Sounds like you want Emacs to become your window manager. It's bloated enough without that. :)
I find sudo edit function very useful for that. After opening a file, press s-e to have sudo access to edit/save the file.