4.17 Android shell setup hints

Android devices use a restricted shell. They can be accessed via the adb method. However, this restricts the access to a USB connection, and it requires the installation of the Android SDK on the local host.

When an sshd process runs on the Android device, like provided by the SSHDroid app, any ssh-based method can be used. This requires some special settings.

The default shell /bin/sh does not exist. Instead, you shall use just sh, which invokes the shell installed on the device. You can instruct TRAMP by this form:

(add-to-list 'tramp-connection-properties
	     (list (regexp-quote "192.168.0.26") "remote-shell" "sh"))

with ‘192.168.0.26’ being the IP address of your Android device (see Predefined connection information).

The user settings for the PATH environment variable must be preserved. It has also been reported, that the commands in /system/xbin are better suited than the ones in /system/bin. Add these setting:

(add-to-list 'tramp-remote-path 'tramp-own-remote-path)
(add-to-list 'tramp-remote-path "/system/xbin")

If the Android device is not ‘rooted’, you must give the shell a writable directory for temporary files:

(add-to-list 'tramp-remote-process-environment "TMPDIR=$HOME")

Now you shall be able to open a remote connection with C-x C-f /ssh:192.168.0.26#2222:, given that sshd listens on port ‘2222’.

It is also recommended to add a corresponding entry to your ~/.ssh/config for that connection, like

Host android
     HostName 192.168.0.26
     User root
     Port 2222

In this case, you must change the setting for the remote shell to

(add-to-list 'tramp-connection-properties
	     (list (regexp-quote "android") "remote-shell" "sh"))

You would open the connection with C-x C-f /ssh:android: then.