4.7 Selecting a default user

The user part of a TRAMP file name can be omitted. Usually, it is replaced by the user name you are logged in. Often, this is not what you want. A typical use of TRAMP might be to edit some files with root permissions on the local host. This case, you should set the variable tramp-default-user to reflect that choice. For example:

(setq tramp-default-user "root")

tramp-default-user is regarded as obsolete, and will be removed soon.

You can also specify different users for certain method/host combinations, via the variable tramp-default-user-alist. For example, if you always have to use the user ‘john’ in the domain ‘somewhere.else’, you can specify the following:

(add-to-list 'tramp-default-user-alist
             '("ssh" ".*\\.somewhere\\.else\\'" "john"))

See the documentation for the variable tramp-default-user-alist for more details.

One trap to fall in must be known. If TRAMP finds a default user, this user will be passed always to the connection command as parameter (for example ssh here.somewhere.else -l john. If you have specified another user for your command in its configuration files, TRAMP cannot know it, and the remote access will fail. If you have specified in the given example in ~/.ssh/config the lines

Host here.somewhere.else
     User lily

than you must discard selecting a default user by TRAMP. This will be done by setting it to nil (or ‘lily’, likewise):

(add-to-list 'tramp-default-user-alist
             '("ssh" "\\`here\\.somewhere\\.else\\'" nil))

The last entry in tramp-default-user-alist could be your default user you’ll apply predominantly. You shall append it to that list at the end:

(add-to-list 'tramp-default-user-alist '(nil nil "jonas") t)