Bash aliases not working over ssh

Question

My Bash aliases are not working over ssh, for example:

$ ssh remote_name ll dir_name
bash: ll: command not found

The Bash man page says:

Aliases are not expanded when the shell is not interactive,
unless the expand_aliases shell option is set using shopt...

So I added shopt -s expand_aliases at the top of my ~/.bashrc file in both the local and remote .bashrc files (since I wasn't sure which was needed - remote right??).

I restarted the local Bash and tried ssh remote_name ll dir_name again, unfortunately I still got the same error bash: ll: command not found.

Can anyone explain what I should do to get this working please?

Just in case my Bash versions are:

Local Bash:
$ bash --version 
GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)

Remote Bash:
$ bash --version 
GNU bash, version 4.3.30(1)-release (x86_64-pc-linux-gnu)

Answer 1

~/.bashrc is read by an non-login, interactive session of bash, not by non-interactive sessions.

ssh remote some_command is running some_command in an non-interactive session of bash, hence the remote ~/.bashrc is not being read (and of course reading the local one is out of question).

Precisely, non-interactive session of bash can read the file defined by the environment variable BASH_ENV or ENV (if set).

If you want to stick with the aliases, open the shell in interactive mode too:

ssh remote bash -ic 'll'

---

Also note that, aliases are standalone, they don't take any argument like you are providing a directory name. You need to use functions to have arguments as inputs. A similar function definition would be:

ll_f () { ls -al --color=auto "$@" ;}

Now you can do:

ll_f /dir_name

Answer 2

My favorite way (in ~/.bashrc):

function bassh() {
    local host=${1:?'arg #1 missing: remote host'}
    shift
    local command="$@"
    local usage="bassh REMOTE_HOST COMMAND"

    [ "$command" ] || {
        echo -e >&2 "[error] no command provided\nUsage: ${usage}"
        return 1
    }

    ssh ${host} -t bash -ic "'${command}'"
}

Note the -t option to ssh which forces pseudo-terminal allocation, thus avoiding related warnings.

Then you call it simply:

$ bassh REMOTE_HOST ll

Answer 3

use

 #!/bin/bash -l

it resolved the issue