Re: Avoid sourcing bashrc when connected to sockets

[Greg Wooledge]

On Mon, Feb 21, 2022 at 11:15:43AM -0800, Andrew Gregory wrote:
> Hmmm, that appears to be a different check, specific to ssh.  That shouldn't 
> be
> what we're hitting.  I believe we're hitting the isnetconn check below it,
> which doesn't appear to be behind a configure option that I can see.  From
> shell.c:
> 
>   /* get the rshd/sshd case out of the way first. */
>   if (interactive_shell == 0 && no_rc == 0 && login_shell == 0 &&
>       act_like_sh == 0 && command_execution_string)
>     {
> #ifdef SSH_SOURCE_BASHRC
>       run_by_ssh = (find_variable ("SSH_CLIENT") != (SHELL_VAR *)0) ||
>                  (find_variable ("SSH2_CLIENT") != (SHELL_VAR *)0);
> #else
>       run_by_ssh = 0;
> #endif
> 
>       /* If we were run by sshd or we think we were run by rshd, execute
>        ~/.bashrc if we are a top-level shell. */
>       if ((run_by_ssh || isnetconn (fileno (stdin))) && shell_level < 2)
>       {
> 

Oh, that's interesting.  Very... historical.  And not configurable at all,
which is what really surprises me.  I wonder why the check for ssh is
configurable (and off by default) but the check for rsh is hard-wired on.
There's a bit of inconsistency here.

Based on that code, I don't think there's any better answer than overriding
the SHLVL variable, as you have already discovered.