Re: Command != command ???

[Philippe Troin <phil@xxxxxxxx>]

Meino Christian Cramer <Meino.Cramer@xxxxxx> writes:

> I am a little confused here -- seems that what I believed to know
> previously is wrong...
> 
> ...I am booting my linux box directly into an X-Server with a kdm
> login...The shell I start then is...interactively, right? .zshrc
> setopts my extendedglob...then I start a script from there...which
> again is not interactively...and will "loose" some features I set in
> my .zshrc...
> 
> Is this correct?

No, when you start a zsh script (A) from a zsh "interactive session"
shell (B), A starts completely anew.  The only thing inherited from B
by A are the environment variables and some other irrelevant state
(opened file descriptors, limits, etc).  All the rest (options, etc)
is lost.

> Is there a list where I can identify those features, which are not
> valid for scripts, if set in .zshrc? Or do I have to read through the
> whole zshall manpage?

In a nutshell:

  zshenv is always read in all non-pathological cases

  zprofile is read if your shell is a login shell

  zshrc is read if your shell is interactive

  zlogin is read if your shell is a login shell

So zprofile and zlogin are equivalent except for the sourcing order
(if one is read, the other is read too).

We have four combinations:

  login and interactive: this is the case when logging in through
  telnet, ssh, and sometimes for shells started by X terminal
  emulators (depending on your settings);

  login and non-interactive: I've only seen it used by some display
  managers when you login (most recent gdm/kdm versions do that, as
  well as CDE);

  non-login interactive: eg. a sub-shell, opened by zsh itself or from
  vi, screen, etc;

  non-login and non-interactive: scripts.

I myself use .zshenv, .zprofile and .zshrc this way:

  In .zshenv, I put: 

      environment variables definitions: bracketed by an if statement,
      and only executed if SOME_VARIABLE is unset.  SOME_VARIABLE is
      set at the end of zshenv);

      some kind of aliases or autoloads: For example ll='ls -l',
      because I want to use ll like this some times: 'ssh machine ll
      /some/dir';

      all the options that are not relevant to interactive use but
      which I may use via 'ssh machine command' (eg. rc_quotes,
      magicequalsubst, etc).

  In .zprofile, I do once-a-time initialization (eg. run under
  ssh-agent if not already), terminal initialization, limits settings,
  everything that's inherited from process to sub-process.

  Finally .zshrc takes care of: completions, zle and keyboard
  settings, prompts, and interactive setopts and autoloads.

Phil.