Question

I have the following command to check if remote client permits to log in with ssh without pass

 ssh -o PasswordAuthentication=no \
     $REMOTE_HOST_USER@$REMOTE_HOST_IP 1>/dev/null 2>/dev/null

Command is executed and if permission=no I am setting permissions at the rest of code. By the way “permissin denied message is sent to /dev/null”. But when the second time I execute my command, this time permission=yes and I must be log in to machine but it hangs of because I think there is no error or output. Cause I tried it like when I got the permission in code;

ssh -o PasswordAuthentication=no $REMOTE_HOST_USER@$REMOTE_HOST_IP

this time works.

So how can i arrange it to send error message for the first time and not to sent at rest

EDIT: As I can explain simple, my questin is that, say i have a command in my script that is possible to give error first time I run my script so i dont want to see erorrs and output and I run it as

command 1>/dev/null 2>/dev/null(it is in my script)

when i run script second time, the command will not give errors and output becaue i made some operations so it does no error.but when it is run second time it hangs becaue of /dev/null(i think so). because when it runs without /dev/null it works fine

Answer 1

Add a command to be executed on the other side.

I typically use : or echo ok. The first one should not produce any output, and I like error messages.

remote_account=$REMOTE_HOST_USER@$REMOTE_HOST_IP 

ssh -o PasswordAuthentication=no $remote_account : 2> /dev/null

or

ssh -o PasswordAuthentication=no $remote_account echo ok | grep ok

The rest of your question is not very clear.