tramp-methods

tramp-methods is a variable defined in `tramp.el'.
Its value is shown below.

Documentation:
Alist of methods for remote files.
This is a list of entries of the form (NAME PARAM1 PARAM2 ...).
Each NAME stands for a remote access method. Each PARAM is a
pair of the form (KEY VALUE). The following KEYs are defined:
* `tramp-remote-shell'
This specifies the shell to use on the remote host. This
MUST be a Bourne-like shell. It is normally not necessary to
set this to any value other than "/bin/sh": Tramp wants to
use a shell which groks tilde expansion, but it can search
for it. Also note that "/bin/sh" exists on all Unixen,
this might not be true for the value that you decide to use.
You Have Been Warned.
* `tramp-remote-shell-args'
For implementation of `shell-command', this specifies the
arguments to let `tramp-remote-shell' run a single command.
* `tramp-login-program'
This specifies the name of the program to use for logging in to the
remote host. This may be the name of rsh or a workalike program,
or the name of telnet or a workalike, or the name of su or a workalike.
* `tramp-login-args'
This specifies the list of arguments to pass to the above
mentioned program. Please note that this is a list of list of arguments,
that is, normally you don't want to put "-a -b" or "-f foo"
here. Instead, you want a list ("-a" "-b"), or ("-f" "foo").
There are some patterns: "%h" in this list is replaced by the host
name, "%u" is replaced by the user name, "%p" is replaced by the
port number, and "%%" can be used to obtain a literal percent character.
If a list containing "%h", "%u" or "%p" is unchanged during
expansion (i.e. no host or no user specified), this list is not used as
argument. By this, arguments like ("-l" "%u") are optional.
"%t" is replaced by the temporary file name produced with
`tramp-make-tramp-temp-file'. "%k" indicates the keep-date
parameter of a program, if exists. "%c" adds additional
`tramp-ssh-controlmaster-options' options for the first hop.
* `tramp-login-env'
A list of environment variables and their values, which will
be set when calling `tramp-login-program'.
* `tramp-async-args'
When an asynchronous process is started, we know already that
the connection works. Therefore, we can pass additional
parameters to suppress diagnostic messages, in order not to
tamper the process output.
* `tramp-copy-program'
This specifies the name of the program to use for remotely copying
the file; this might be the absolute filename of scp or the name of
a workalike program. It is always applied on the local host.
* `tramp-copy-args'
This specifies the list of parameters to pass to the above mentioned
program, the hints for `tramp-login-args' also apply here.
* `tramp-copy-env'
A list of environment variables and their values, which will
be set when calling `tramp-copy-program'.
* `tramp-remote-copy-program'
The listener program to be applied on remote side, if needed.
* `tramp-remote-copy-args'
The list of parameters to pass to the listener program, the hints
for `tramp-login-args' also apply here. Additionally, "%r" could
be used here and in `tramp-copy-args'. It denotes a randomly
chosen port for the remote listener.
* `tramp-copy-keep-date'
This specifies whether the copying program when the preserves the
timestamp of the original file.
* `tramp-copy-keep-tmpfile'
This specifies whether a temporary local file shall be kept
for optimization reasons (useful for "rsync" methods).
* `tramp-copy-recursive'
Whether the operation copies directories recursively.
* `tramp-default-port'
The default port of a method is needed in case of gateway connections.
Additionally, it is used as indication which method is prepared for
passing gateways.
* `tramp-gw-args'
As the attribute name says, additional arguments are specified here
when a method is applied via a gateway.
* `tramp-tmpdir'
A directory on the remote host for temporary files. If not
specified, "/tmp" is taken as default.
* `tramp-connection-timeout'
This is the maximum time to be spent for establishing a connection.
In general, the global default value shall be used, but for
some methods, like "su" or "sudo", a shorter timeout
might be desirable.

What does all this mean? Well, you should specify `tramp-login-program'
for all methods; this program is used to log in to the remote site. Then,
there are two ways to actually transfer the files between the local and the
remote side. One way is using an additional scp-like program. If you want
to do this, set `tramp-copy-program' in the method.

Another possibility for file transfer is inline transfer, i.e. the
file is passed through the same buffer used by `tramp-login-program'. In
this case, the file contents need to be protected since the
`tramp-login-program' might use escape codes or the connection might not
be eight-bit clean. Therefore, file contents are encoded for transit.
See the variables `tramp-local-coding-commands' and
`tramp-remote-coding-commands' for details.

So, to summarize: if the method is an out-of-band method, then you
must specify `tramp-copy-program' and `tramp-copy-args'. If it is an
inline method, then these two parameters should be nil. Methods which
are fit for gateways must have `tramp-default-port' at least.

Notes:

When using `su' or `sudo' the phrase `open connection to a remote
host' sounds strange, but it is used nevertheless, for consistency.
No connection is opened to a remote host, but `su' or `sudo' is
started on the local host. You should specify a remote host
`localhost' or the name of the local host. Another host name is
useful only in combination with `tramp-default-proxies-alist'.

Value:

(("smb"
  (tramp-remote-shell "")
  (tramp-tmpdir "/C$/Temp"))
 ("fcp"
  (tramp-login-program "fsh")
  (tramp-login-args
   (("%h")
    ("-l" "%u")
    ("sh" "-i")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-i")
   ("-c"))
  (tramp-copy-program "fcp")
  (tramp-copy-args
   (("-p" "%k")))
  (tramp-copy-keep-date t))
 ("psftp"
  (tramp-login-program "plink")
  (tramp-login-args
   (("-l" "%u")
    ("-P" "%p")
    ("-ssh")
    ("-t")
    ("%h")
    ("\"")
    ("env 'TERM=dumb' 'PROMPT_COMMAND=' 'PS1=#$ '")
    ("/bin/sh")
    ("\"")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "pscp")
  (tramp-copy-args
   (("-l" "%u")
    ("-P" "%p")
    ("-sftp")
    ("-p" "%k")
    ("-q")
    ("-r")))
  (tramp-copy-keep-date t)
  (tramp-copy-recursive t))
 ("pscp"
  (tramp-login-program "plink")
  (tramp-login-args
   (("-l" "%u")
    ("-P" "%p")
    ("-ssh")
    ("-t")
    ("%h")
    ("\"")
    ("env 'TERM=dumb' 'PROMPT_COMMAND=' 'PS1=#$ '")
    ("/bin/sh")
    ("\"")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "pscp")
  (tramp-copy-args
   (("-l" "%u")
    ("-P" "%p")
    ("-scp")
    ("-p" "%k")
    ("-q")
    ("-r")))
  (tramp-copy-keep-date t)
  (tramp-copy-recursive t)
  (tramp-default-port 22))
 ("plinkx"
  (tramp-login-program "plink")
  (tramp-login-args
   (("-load")
    ("%h")
    ("-t")
    ("\"")
    ("env 'TERM=dumb' 'PROMPT_COMMAND=' 'PS1=#$ '")
    ("/bin/sh")
    ("\"")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c")))
 ("plink"
  (tramp-login-program "plink")
  (tramp-login-args
   (("-l" "%u")
    ("-P" "%p")
    ("-ssh")
    ("-t")
    ("%h")
    ("\"")
    ("env 'TERM=dumb' 'PROMPT_COMMAND=' 'PS1=#$ '")
    ("/bin/sh")
    ("\"")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-default-port 22))
 ("krlogin"
  (tramp-login-program "krlogin")
  (tramp-login-args
   (("%h")
    ("-l" "%u")
    ("-x")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c")))
 ("ksu"
  (tramp-login-program "ksu")
  (tramp-login-args
   (("%u")
    ("-q")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-connection-timeout 10))
 ("sudo"
  (tramp-login-program "sudo")
  (tramp-login-args
   (("-u" "%u")
    ("-s")
    ("-H")
    ("-p" "Password:")))
  (tramp-login-env
   (("SHELL")
    ("/bin/sh")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-connection-timeout 10))
 ("su"
  (tramp-login-program "su")
  (tramp-login-args
   (("-")
    ("%u")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-connection-timeout 10))
 ("nc"
  (tramp-login-program "telnet")
  (tramp-login-args
   (("%h")
    ("%p")
    ("2>/dev/null")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "nc")
  (tramp-copy-args
   (("-w" "1")
    ("-v")
    ("%h")
    ("%r")))
  (tramp-remote-copy-program "nc")
  (tramp-remote-copy-args
   (("-l")
    ("-p" "%r")))
  (tramp-default-port 23))
 ("telnet"
  (tramp-login-program "telnet")
  (tramp-login-args
   (("%h")
    ("%p")
    ("2>/dev/null")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-default-port 23))
 ("sshx"
  (tramp-login-program "ssh")
  (tramp-login-args
   (("-l" "%u")
    ("-p" "%p")
    ("%c")
    ("-e" "none")
    ("-t" "-t")
    ("%h")
    ("/bin/sh")))
  (tramp-async-args
   (("-q")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-gw-args
   (("-o" "GlobalKnownHostsFile=/dev/null")
    ("-o" "UserKnownHostsFile=/dev/null")
    ("-o" "StrictHostKeyChecking=no")))
  (tramp-default-port 22))
 ("ssh"
  (tramp-login-program "ssh")
  (tramp-login-args
   (("-l" "%u")
    ("-p" "%p")
    ("%c")
    ("-e" "none")
    ("%h")))
  (tramp-async-args
   (("-q")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-gw-args
   (("-o" "GlobalKnownHostsFile=/dev/null")
    ("-o" "UserKnownHostsFile=/dev/null")
    ("-o" "StrictHostKeyChecking=no")))
  (tramp-default-port 22))
 ("remsh"
  (tramp-login-program "remsh")
  (tramp-login-args
   (("%h")
    ("-l" "%u")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c")))
 ("rsh"
  (tramp-login-program "rsh")
  (tramp-login-args
   (("%h")
    ("-l" "%u")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c")))
 ("rsync"
  (tramp-login-program "ssh")
  (tramp-login-args
   (("-l" "%u")
    ("-p" "%p")
    ("%c")
    ("-e" "none")
    ("%h")))
  (tramp-async-args
   (("-q")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "rsync")
  (tramp-copy-args
   (("-t" "%k")
    ("-r")))
  (tramp-copy-env
   (("RSYNC_RSH")
    ("ssh" "%c")))
  (tramp-copy-keep-date t)
  (tramp-copy-keep-tmpfile t)
  (tramp-copy-recursive t))
 ("scpx"
  (tramp-login-program "ssh")
  (tramp-login-args
   (("-l" "%u")
    ("-p" "%p")
    ("%c")
    ("-e" "none")
    ("-t" "-t")
    ("%h")
    ("/bin/sh")))
  (tramp-async-args
   (("-q")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "scp")
  (tramp-copy-args
   (("-P" "%p")
    ("-p" "%k")
    ("-q")
    ("-r")
    ("%c")))
  (tramp-copy-keep-date t)
  (tramp-copy-recursive t)
  (tramp-gw-args
   (("-o" "GlobalKnownHostsFile=/dev/null")
    ("-o" "UserKnownHostsFile=/dev/null")
    ("-o" "StrictHostKeyChecking=no")))
  (tramp-default-port 22))
 ("scp"
  (tramp-login-program "ssh")
  (tramp-login-args
   (("-l" "%u")
    ("-p" "%p")
    ("%c")
    ("-e" "none")
    ("%h")))
  (tramp-async-args
   (("-q")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "scp")
  (tramp-copy-args
   (("-P" "%p")
    ("-p" "%k")
    ("-q")
    ("-r")
    ("%c")))
  (tramp-copy-keep-date t)
  (tramp-copy-recursive t)
  (tramp-gw-args
   (("-o" "GlobalKnownHostsFile=/dev/null")
    ("-o" "UserKnownHostsFile=/dev/null")
    ("-o" "StrictHostKeyChecking=no")))
  (tramp-default-port 22))
 ("remcp"
  (tramp-login-program "remsh")
  (tramp-login-args
   (("%h")
    ("-l" "%u")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "rcp")
  (tramp-copy-args
   (("-p" "%k")))
  (tramp-copy-keep-date t))
 ("rcp"
  (tramp-login-program "rsh")
  (tramp-login-args
   (("%h")
    ("-l" "%u")))
  (tramp-remote-shell "/bin/sh")
  (tramp-remote-shell-args
   ("-c"))
  (tramp-copy-program "rcp")
  (tramp-copy-args
   (("-p" "%k")
    ("-r")))
  (tramp-copy-keep-date t)
  (tramp-copy-recursive t))
 ("synce")
 ("sftp")
 ("obex")
 ("davs")
 ("dav")
 ("ftp")
 ("adb"
  (tramp-tmpdir "/data/local/tmp")))