Bug 2860

Summary:	"-lc" should be used for non-interactive session
Product:	Portable OpenSSH	Reporter:	Tom Yan <tom.ty89>
Component:	ssh	Assignee:	Assigned to nobody <unassigned-bugs>
Status:	CLOSED WONTFIX
Severity:	normal	CC:	djm
Priority:	P5
Version:	7.7p1
Hardware:	Other
OS:	Linux

Description Tom Yan 2018-04-20 18:47:08 AEST

https://github.com/openssh/openssh-portable/blob/V_7_7/session.c#L1668

In interactive sessions, the shell would be started as "login shell", /etc/profile (or zprofile in the case of zsh) would be sourced.

However, when user instructs ssh to execute a command with a non-interactive session, because the shell is started without -l / -- login, the profile files would not be sourced, which leads to inconsistency among the two types of sessions (typically missing expected environment variables in the non-interactive session).

Is there any reason that the shell in a non-interactive session should not be started as "login shell"?

Comment 1 Damien Miller 2018-05-02 01:26:54 AEST

That inconsistency is intentional. Command execution sessions are assumed to be non-interactive and are essential to ssh's use as a transport for other protocols (e.g. rsync or git).

Shell profile scripts are allows to contain actions that write to stdout and these would interfere with ssh being used as a transport if sourced.

Comment 2 Tom Yan 2018-05-03 15:57:10 AEST

> Command execution sessions are assumed to be non-interactive

Of course, but login shell is not equivalent to interactive shell


> Shell profile scripts are allows to contain actions that write to stdout and these would interfere with ssh being used as a transport if sourced

It is the responsibility of the script writer that he/she should make sure such actions are only performed in interactive shell (e.g. by checking whether "$-" has i, or by putting them in the "rc" file instead).

It does not really make sense to break the non-interactive command execution environment just for that, because ssh is logging in either way.

Comment 3 Damien Miller 2018-05-04 02:43:25 AEST

We don't intend to change this for the reasons that I've already described.

Comment 4 Damien Miller 2018-10-19 17:17:23 AEDT

Close RESOLVED bugs with the release of openssh-8.0