What is the benefit, other than the formal differences, of using a login
shell vs. not using it? - Mac OS X has two consoles, "Terminal" creating a
login shell and 'xterm' not creating it (in 'bash'), both typically opened
after the GUI login, and it is easy to change it.

Hans Aberg

In article <haberg-1905071829240001@c83-250-192-69.bredband.comhem.se>,
haberg@math.su.se (Hans Aberg) wrote:

> What is the benefit, other than the formal differences, of using a login
> shell vs. not using it? - Mac OS X has two consoles, "Terminal" creating a
> login shell and 'xterm' not creating it (in 'bash'), both typically opened

xterm will create a login shell if you give it the -ls option.

> after the GUI login, and it is easy to change it.

A login shell will run the .profile startup script to initialize
environment variables for the login session.

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

In article <barmar-EE5BDC.22234519052007@comcast.dca.giganews.com>, Barry
Margolin <barmar@alum.mit.edu> wrote:

> > What is the benefit, other than the formal differences, of using a login
> > shell vs. not using it? - Mac OS X has two consoles, "Terminal" creating a
> > login shell and 'xterm' not creating it (in 'bash'), both typically opened
>
> xterm will create a login shell if you give it the -ls option.
>
> > after the GUI login, and it is easy to change it.
>
> A login shell will run the .profile startup script to initialize
> environment variables for the login session.

Thank you, Barry, but those are the formal differences. If I turn off the
login shell, but otherwise use the same startup (but from a different
file), will I loose anything?

[In order to get the Unicode locale working in Terminal, I have in
Preferences -> Execute this command put
/usr/bin/env LC_CTYPE=UTF-8 /bin/bash -l
If I do not want the login shell, I just take away the -l. (In latest
xterm, it suffices to just put 'export LC_CTYPE=UTF-8' somewhere in the
startup.)]

Hans Aberg

In article <haberg-2005071049170001@c83-250-192-69.bredband.comhem.se>,
haberg@math.su.se (Hans Aberg) wrote:

> In article <barmar-EE5BDC.22234519052007@comcast.dca.giganews.com>, Barry
> Margolin <barmar@alum.mit.edu> wrote:
>
> > > What is the benefit, other than the formal differences, of using a login
> > > shell vs. not using it? - Mac OS X has two consoles, "Terminal" creating a
> > > login shell and 'xterm' not creating it (in 'bash'), both typically opened
> >
> > xterm will create a login shell if you give it the -ls option.
> >
> > > after the GUI login, and it is easy to change it.
> >
> > A login shell will run the .profile startup script to initialize
> > environment variables for the login session.
>
> Thank you, Barry, but those are the formal differences. If I turn off the
> login shell, but otherwise use the same startup (but from a different
> file), will I loose anything?

The point is that some shells don't run ANY startup script automatically
if they're not a login shell. Bash runs the script named in $ENV, but
you usually need to set that variable in another startup script -- it
will then be used by descendant shells.

> [In order to get the Unicode locale working in Terminal, I have in
> Preferences -> Execute this command put
> /usr/bin/env LC_CTYPE=UTF-8 /bin/bash -l
> If I do not want the login shell, I just take away the -l. (In latest
> xterm, it suffices to just put 'export LC_CTYPE=UTF-8' somewhere in the
> startup.)]

If you have an alternate, system-specific way to initialize variables
then you don't need to worry about the login shell distinction. It's
mainly a remnant from the days of ASCII terminals with a single login
session. It's harder to fit into the multi-window modern environment,
where shell windows are not typically descendants of an initial shell
(they usually descend from the window manager).

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

In article <barmar-2C673F.10513120052007@comcast.dca.giganews.com>, Barry
Margolin <barmar@alum.mit.edu> wrote:

> > Thank you, Barry, but those are the formal differences. If I turn off the
> > login shell, but otherwise use the same startup (but from a different
> > file), will I loose anything?
>
> The point is that some shells don't run ANY startup script automatically
> if they're not a login shell. Bash runs the script named in $ENV, but
> you usually need to set that variable in another startup script -- it
> will then be used by descendant shells.

OK. Fine.

> If you have an alternate, system-specific way to initialize variables
> then you don't need to worry about the login shell distinction. It's
> mainly a remnant from the days of ASCII terminals with a single login
> session. It's harder to fit into the multi-window modern environment,
> where shell windows are not typically descendants of an initial shell
> (they usually descend from the window manager).

There is such a method on Mac OS X: one can use a file
~/.MacOSX/environment.plist.

I just compiled that latest C-version of Modules <comp.sys.mac.system>
under Mac OS 10.4.9 (latest). All I had to do is to add an option '-lX11'
to the last gcc linking command, which otherwise fails. I haven't checked
if it works, though.

Hans Aberg

In article <barmar-EE5BDC.22234519052007@comcast.dca.giganews.com>, Barry
Margolin <barmar@alum.mit.edu> wrote:

> > What is the benefit, other than the formal differences, of using a login
> > shell vs. not using it? - Mac OS X has two consoles, "Terminal" creating a
> > login shell and 'xterm' not creating it (in 'bash'), both typically opened
>
> xterm will create a login shell if you give it the -ls option.

Detail: One can start X Window programs without a console, for example
from the X11 "File" menu, in which case .bashrc will be executed, not
..profile. So this lessens the point of making xterm a login shell.

Hans Aberg