Change directory on invocation of zsh

Change directory on invocation of zsh

[Michael Prokop]

Hello,

I'm using the latest zsh version of debian unstable (4.2.1).
I'm using rungetty on one of my systems.
My /etc/inittab looks like this:


1:12345:respawn:/bin/zsh --login -c "/usr/bin/grml-start ; /usr/bin/grml-screen" >/dev/tty1 2>&1 </dev/tty1
[...]
5:2345:respawn:/sbin/rungetty tty5 -u grml -g grml --autologin grml /bin/zsh


So I'm able to use autologin without doing login stuff.

My problem: when starting zsh my working directory is '/'.
Not just as user root but also as user 'grml'.

AFAIK the pam_env module is responsible for doing some basic
enviroment handling.  Because I don't use the PAM system I've a
little wrapper in my zsh config:

  ,---- [ /etc/zsh/zshrc ]
  | if [[ -z "$HOME" || "$HOME" == "/" ]] ; then
  |   if [[ `id -un` == "root" ]] ; then
  |      export HOME=/root
  |   else
  |      export HOME=/home/`id -un`
  |   fi
  | fi
  `----

Of course running 'cd' or 'cd $HOME' or 'cd ~' changes into my
homedirectory. But I'd like to change path already on login.
Doing something like '[ $SECONDS == "0" ] && cd $HOME' is a
workaround but changes the working directory to $HOME any time I'm
starting a new zsh. Am I on the wrong way?
Any ideas or any hints? Thanks!

thx && regards,
(-: Michael

Re: Change directory on invocation of zsh

[Bart Schaefer]

On Sat, 16 Oct 2004, Michael Prokop wrote:

> little wrapper in my zsh config:
> 
>   ,---- [ /etc/zsh/zshrc ]

Why zshrc rather than zshenv?  The wrong ~/.zshenv will be loaded if $HOME 
is not set correctly before the end of the global zshenv.

>   | if [[ -z "$HOME" || "$HOME" == "/" ]] ; then
>   |   if [[ `id -un` == "root" ]] ; then
>   |      export HOME=/root
>   |   else
>   |      export HOME=/home/`id -un`
>   |   fi
>   | fi
>   `----

Using `id -un` there, particularly twice, should not be necessary.  E.g.,

  if (( EUID == 0 )); then
     export HOME=/root
  else
     export HOME=/home/$LOGNAME
  fi

> Of course running 'cd' or 'cd $HOME' or 'cd ~' changes into my
> homedirectory. But I'd like to change path already on login.

So whether HOME is set correctly (before executing the above snippet) has 
nothing to do with whether the current directory is "/" ?  I would expect 
the two conditions to be related, e.g.,

  if [[ -z "$HOME" || "$HOME" == "/" ]] ; then
     # ... export $HOME correctly, then ...
     cd
  fi

Or is there some reason you don't want to have the "cd" in the global 
config?

> Doing something like '[ $SECONDS == "0" ] && cd $HOME' is a
> workaround but changes the working directory to $HOME any time I'm
> starting a new zsh. Am I on the wrong way?

How about something like

   if [[ -z "$ALREADY_DID_CD_HOME" ]]; then
      export ALREADY_DID_CD_HOME=$HOME
      cd
   fi

Re: Change directory on invocation of zsh

[Michael Prokop]

Bart, thanks a lot for your fast reply!

* Bart Schaefer <schaefer@brasslantern.com> [20041017 10:13]:
> On Sat, 16 Oct 2004, Michael Prokop wrote:

> > little wrapper in my zsh config:

> >   ,---- [ /etc/zsh/zshrc ]

> Why zshrc rather than zshenv?  The wrong ~/.zshenv will be loaded if $HOME 
> is not set correctly before the end of the global zshenv.

Upps. Corrected, thanks.

> >   | if [[ -z "$HOME" || "$HOME" == "/" ]] ; then
> >   |   if [[ `id -un` == "root" ]] ; then
> >   |      export HOME=/root
> >   |   else
> >   |      export HOME=/home/`id -un`
> >   |   fi
> >   | fi
> >   `----

> Using `id -un` there, particularly twice, should not be necessary.  E.g.,

>   if (( EUID == 0 )); then
>      export HOME=/root
>   else
>      export HOME=/home/$LOGNAME
>   fi

Thanks.

It seems to work on the "last tty", but on the other ones I'm getting:

/etc/zsh/zshrc:cd:22: no such file or directory: /home/LOGIN
$ echo $LOGNAME
LOGIN
$ whoami
grml
$ id -un
grml

I can't find the reason for this behaviour (inittab entries are the
same and behaviour seems to change when booting system serveral
times), but using `id -un` instead of $LOGNAME seems to fix it.

> > Of course running 'cd' or 'cd $HOME' or 'cd ~' changes into my
> > homedirectory. But I'd like to change path already on login.

> So whether HOME is set correctly (before executing the above snippet) has 
> nothing to do with whether the current directory is "/" ?  I would expect 
> the two conditions to be related, e.g.,

>   if [[ -z "$HOME" || "$HOME" == "/" ]] ; then
>      # ... export $HOME correctly, then ...
>      cd
>   fi

> Or is there some reason you don't want to have the "cd" in the global 
> config?

Ah, ok - I see what you mean. Yes, seems to be related.

> > Doing something like '[ $SECONDS == "0" ] && cd $HOME' is a
> > workaround but changes the working directory to $HOME any time I'm
> > starting a new zsh. Am I on the wrong way?

> How about something like

>    if [[ -z "$ALREADY_DID_CD_HOME" ]]; then
>       export ALREADY_DID_CD_HOME=$HOME
>       cd
>    fi

Oh, my thinking was too complicated. :)
Thanks Bart, works like a charme!

thx && regards,
(-: Michael

Re: Change directory on invocation of zsh

[Bart Schaefer]

On Sun, 17 Oct 2004, Michael Prokop wrote:

> * Bart Schaefer <schaefer@brasslantern.com> [20041017 10:13]:
> >   if (( EUID == 0 )); then
> >      export HOME=/root
> >   else
> >      export HOME=/home/$LOGNAME
> >   fi
> 
> /etc/zsh/zshrc:cd:22: no such file or directory: /home/LOGIN
> $ echo $LOGNAME
> LOGIN

Hm.  This means that one of the following occurred:

- getlogin() returned "LOGIN"

- getlogin() returned empty or null, and getpwuid() returned an entry for
  the user named "LOGIN"

I'd have to guess this is a side-effect of autologin?  Does it run as the
user "LOGIN"?

> I can't find the reason for this behaviour (inittab entries are the
> same and behaviour seems to change when booting system serveral
> times), but using `id -un` instead of $LOGNAME seems to fix it.

If you can't figure out how to get it to be consistent, I'd suggest adding
to /etc/zsh/zshenv this snippet:

  [[ $LOGNAME == LOGIN ]] && LOGNAME=$(id -un)

Do that before the EUID/HOME snippet.  Other things may be depending on 
LOGNAME being set correctly, too.

Re: Change directory on invocation of zsh

[Michael Prokop]

* Bart Schaefer <schaefer@brasslantern.com> [20041017 18:28]:
> On Sun, 17 Oct 2004, Michael Prokop wrote:
> > * Bart Schaefer <schaefer@brasslantern.com> [20041017 10:13]:

> > >   if (( EUID == 0 )); then
> > >      export HOME=/root
> > >   else
> > >      export HOME=/home/$LOGNAME
> > >   fi

> > /etc/zsh/zshrc:cd:22: no such file or directory: /home/LOGIN
> > $ echo $LOGNAME
> > LOGIN

> Hm.  This means that one of the following occurred:

> - getlogin() returned "LOGIN"

> - getlogin() returned empty or null, and getpwuid() returned an entry for
>   the user named "LOGIN"

[.../rungetty-1.2]$ grep LOGIN rungetty.c
#ifndef _PATH_LOGIN
#define _PATH_LOGIN "/bin/login"
#define LOGIN " login: "        /* login prompt */
  strncpy (ut.ut_user, "LOGIN", sizeof (ut.ut_user));
  ut.ut_type = LOGIN_PROCESS;
  write (1, LOGIN, sizeof (LOGIN) - 1);
      execl (_PATH_LOGIN, _PATH_LOGIN, "-f", autologin_name, NULL);
      execl (_PATH_LOGIN, _PATH_LOGIN, "--", logname, NULL);
  error ("%s: can't exec " _PATH_LOGIN ": %s", tty, sys_errlist[errno]);
[.../rungetty-1.2]$

> I'd have to guess this is a side-effect of autologin?  Does it run as the
> user "LOGIN"?

This seems to be a side-effect of rungetty's autologin, yes.
rungetty should run as user root or as the user specified in
/etc/inittab, in my case this is user 'grml':

4:2345:respawn:/sbin/rungetty tty4 -u grml -g grml --autologin grml /bin/zsh

I'm in contact with the debian maintainer of the rungetty-package.

> > I can't find the reason for this behaviour (inittab entries are the
> > same and behaviour seems to change when booting system serveral
> > times), but using `id -un` instead of $LOGNAME seems to fix it.

> If you can't figure out how to get it to be consistent, I'd suggest adding
> to /etc/zsh/zshenv this snippet:

>   [[ $LOGNAME == LOGIN ]] && LOGNAME=$(id -un)

> Do that before the EUID/HOME snippet.  Other things may be depending on 
> LOGNAME being set correctly, too.

Thanks, works like a charme!

regards,
(-: Michael