Execute Command on Remote Server via Ssh

Using ssh to login to linux terminal from windows and run command in a logged in shell

Try this :

start cmd /k ssh user@host "/full/path/to/roslaunch launchFile.launch; exec /bin/bash"

How to execute a remote command over ssh with arguments?

Do it this way instead:

function mycommand {
    ssh user@123.456.789.0 "cd testdir;./test.sh \"$1\""
}

You still have to pass the whole command as a single string, yet in that single string you need to have $1 expanded before it is sent to ssh so you need to use "" for it.

Update

Another proper way to do this actually is to use printf %q to properly quote the argument. This would make the argument safe to parse even if it has spaces, single quotes, double quotes, or any other character that may have a special meaning to the shell:

function mycommand {
    printf -v __ %q "$1"
    ssh user@123.456.789.0 "cd testdir;./test.sh $__"
}

When declaring a function with function, () is not necessary.
Don't comment back about it just because you're a POSIXist.

Starting Bash version 4.4, it can also be simplified to this:

function mycommand {
    ssh user@123.456.789.0 "cd testdir;./test.sh ${1@Q}"
}

See ${parameter@operator} section in Shell Parameter Expansion.

SSH remote machine and execute command

Let's use set -x to debug what we actually run:

$ set -x
$ ssh localhost echo $PATH
+ ssh localhost echo /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games

The line with the + tells us that the command we actually run is:

ssh localhost echo /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games

Unsurprisingly, this is also the value we get back, regardless of what the remote PATH is.

We can single quote the command to ensure that we send echo $PATH instead of echo /usr/local/bin:... to the server:

$ ssh localhost 'echo $PATH'
+ ssh localhost 'echo $PATH'

Now set -x shows that ssh is being run with the unexpanded command instead of the expanded command, and we get the remote PATH in return.