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

Posted on in Categories News last updated February 5, 2006

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 [email protected] 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 [email protected] 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 [email protected] 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 [email protected] 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.

11 comment

  1. Suppose I put a job to run on remote server (in the background and logged. How can I check later whether the job is done or not.
    Suppose if i know the Job ID ??

  2. I am using remsh to execute remote command.
    How to obtain exit status of remotely executed command .In remote program i am using exit(number) to differinciate b/w exit status.But all time i get exit status as 0.
    Even if i use abort() the exit status is 0.
    SOme one help???????????/

  3. Additional note:
    After trying this one. i found out that if ssh cannot resolve the host, the exit status is 255.

  4. Um, I think the reason that

    ssh [email protected] today;echo $? || echo "Command failed"

    doesn’t work is because the echo $? changes the exit status, not because of weirdness with SSH.

  5. Just do
    (ssh [email protected] “command_does_not_exists” >/dev/null 2>&1) || echo “Command doesn’t exists! HOSTNAME: $(hostname)”

    you can pass -i /path/to/private-key to authenticate to the remote machine using an ssh key if you don’t want to use ssh-agent or other stuff like that (useful when doing remote automations, you can use in rsync too with -e or in git using a simple wrapper)

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