detecting when I'm logged in remotely?

[Tub]

Hi,

I like to have a prompt that'll highlight anything I should be aware of. Let's say I'm sitting at computer 'local' and there's a server 'server' I can ssh to. I managed to set up my bashrcs to do the following:

tub@local: (everything's fine, no colors)
root@local: (root! be careful)
tub@server: (careful, this is not the machine I'm sitting at!)
root@server: this is wrong. the hostname should be red.

I'm currently checking for the presence of environment variables ($SSH_CLIENT / $SSH_CONNECTION) to determine if this is a local login. But when I su - on the remote host, the environment variables are removed, and my prompt doesn't warn me any more.

Of course I could use su instead of su - (or su -p or whatever), but that's not a good idea.


Another way to check remote logins would be to check if one of the parent processes of the shell is called 'sshd'. I can get that information from pstree -h, but that's not good for automatic parsing at all. Neither 'man ps' nor browsing /proc brought me closer to a solution.


Anyone with a better idea?
_________________
m00

[javeree_work]

Just from memory:

I believe the command 'tty' returns /dev/ttyx if you are working locally and dev/ptyx (or some other acronym meaning 'pseudoterminal') if you are working remote.

Also check the command 'fgconsole'

[Tub]

thank you.

Unfortunately xterm/aterm/konsole (and probably every other x11-terminal) use virtual ttys even when working locally. /dev/tty/x is only used on the framebuffer-consoles (Strg-Alt-F1 to F6). Since I'm mostly using aterm, sometimes putty and very rarely a framebuffer console, that check won't help.
_________________
m00

[Tub]

browsing the pstree source code revealed that the PID of the parent process is available via /proc/$PID/stats .. so I can do a simple recursive lookup.