How do I find the exit status of a remote command executed via ssh?

After writing about "Execute Commands on Multiple Linux or UNIX Servers", I received couple of emails asking about "how to find out the exit status of a remote command executed via ssh command." Well I never ever used exit status of a remote command executed via ssh. However, here is simple way to find out exit status:

$ ssh user@ras.nixcraft.in date;echo $?

Sun Feb  5 19:01:01 IST 2006
0

First line is nothing but output of date command, zero (0) is exit status of date command. Try another command

$ ssh user@ras.nixcraft.in today;echo $?

bash: today: command not found
127

Please note that ssh exits with the exit status of the remote command or with 255 if an error occurred. For example:

$ ssh user@ras.nixcraft.in today
$ echo $?

bash: today: command not found
127

Since today is not a valid command bash exited with 127 exit code. However, you cannot use conditional control operator:

• && : Execute command only if command returns an exit status of zero
• || : Execute command only if command returns an exit status of non zero

So following command will never display Command failed message:

$ ssh root@192.168.1.16 today;echo $? || echo "Command failed"

What you can do is create a shell script wrapper that will execute a remote command and returns the status locally. So if you are using scripts then last line will be always using to determine the exit status of a remote command executed via ssh.