Z-Shell (zsh) FAQ changes this month

[Peter Stephenson <pws@xxxxxxxxxxxxxxxxx>]

This file contains general information on how to find out about zsh,
(the first part of the FAQ up to item 1.1), then any other items which
have changed since last month's posting, then the differences in the
text version of the FAQ.  If you would like a complete individual
copy, email me and I will add you to the list.


Changes since issue posted March 1999:

1.5  Mention 3.0.6 should appear soon
5.1  Update on history-search-backward saga

This document contains a list of frequently-asked (or otherwise
significant) questions concerning the Z-shell, a command interpreter
for many UNIX systems which is freely available to anyone with FTP
access.  Zsh is among the most powerful freely available Bourne-like
shell for interactive use.

If you have never heard of `sh', `csh' or `ksh', then you are
probably better off to start by reading a general introduction to UNIX
rather than this document.

If you just want to know how to get your hands on the latest version,
skip to question 1.6; if you want to know what to do with
insoluble problems, go to 5.2.

Notation: Quotes `like this' are ordinary textual quotation
marks.  Other uses of quotation marks are input to the shell.

Contents:
Chapter 1:  Introducing zsh and how to install it
1.1. Sources of information
1.2. What is it?
1.3. What is it good at?
1.4. On what machines will it run?  (Plus important compilation notes)
1.5. What's the latest version?
1.6. Where do I get it?
1.7. I don't have root access: how do I make zsh my login shell?

Chapter 2:  How does zsh differ from...?
2.1. sh and ksh?
2.2. csh?
2.3. Why do my csh aliases not work?  (Plus other alias pitfalls.)
2.4. tcsh?
2.5. bash?
2.6. Shouldn't zsh be more/less like ksh/(t)csh?

Chapter 3:  How to get various things to work
3.1. Why does `$var' where `var="foo bar"' not do what I expect?
3.2. In which startup file do I put...?
3.3. What is the difference between `export' and the ALL_EXPORT option?
3.4. How do I turn off spelling correction/globbing for a single command?
3.5. How do I get the meta key to work on my xterm?
3.6. How do I automatically display the directory in my xterm title bar?
3.7. How do I make the completion list use eight bit characters?
3.8. Why do the cursor (arrow) keys not work?
3.9. Why does my terminal act funny in some way?
3.10. Why does zsh not work in an Emacs shell mode any more?
3.11. Why do my autoloaded functions not autoload [the first time]?
3.12. How does base arithmetic work?
3.13. How do I get a newline in my prompt?
3.14. Why does `bindkey ^a command-name' or 'stty intr ^-' do something funny?
3.15. Why can't I bind \C-s and \C-q any more?
3.16. How do I execute command `foo' within function `foo'?
3.17. Why do history substitutions with single bangs do something funny?
3.18. Why does zsh kill off all my background jobs when I logout?
3.19. How do I list all my history entries?
3.20. How does the alternative loop syntax, e.g. `while {...} {...}' work?
3.21. Why is my history not being saved?
3.22. How do I get a variable's value to be evaluated as another variable?

Chapter 4:  The mysteries of completion
4.1. What is completion?
4.2. What sorts of things can be completed?
4.3. How does zsh deal with ambiguous completions?
4.4. How do I complete in the middle of words / just what's before the cursor?
4.5. How do I get started with programmable completion?
4.6. And if programmable completion isn't good enough?

Chapter 5:  The future of zsh
5.1. What bugs are currently known and unfixed? (Plus recent important changes)
5.2. Where do I report bugs, get more info / who's working on zsh?
5.3. What's on the wish-list?
5.4. Will zsh have problems in the year 2000?

Acknowledgments

Copyright
--- End of Contents ---

Chapter 1: Introducing zsh and how to install it

1.1: Sources of information

  Information on zsh is available via the World Wide Web.  The URL
  is http://sunsite.auc.dk/zsh/ (note the change of address from the
  end of April 1998).  The server provides this FAQ and much else and is
  now maintained by Karsten Thygesen and others (mail zsh@xxxxxxxxxxxxxx
  with any related messages).  The FAQ is at http://sunsite.auc.dk/zsh/FAQ/ .
  The site also contains some contributed zsh scripts and functions;
  we are delighted to add more, or simply links to your own collection.

  This document was originally written in YODL, allowing it to be converted
  easily into various other formats.  The master source file lives at
  http://sunsite.auc.dk/zsh/FAQ/zshfaq.yo and the plain text version
  can be found at http://sunsite.auc.dk/zsh/FAQ/zshfaq.txt .

  Another useful source of information is the collection of FAQ articles
  posted frequently to the Usenet news groups comp.unix.questions,
  comp.unix.shells and comp.answers with answers to general questions
  about UNIX.  The fifth of the seven articles deals with shells,
  including zsh, with a brief description of differences.  There is
  also a separate FAQ on shell differences and how to change your
  shell.  Usenet FAQs are available via FTP from rtfm.mit.edu and
  mirrors and also on the World Wide Web; see

    USA         http://www.cis.ohio-state.edu/hypertext/faq/usenet/top.html
    UK          http://www.lib.ox.ac.uk/internet/news/faq/comp.unix.shell.html
    Netherlands http://www.cs.uu.nl/wais/html/na-dir/unix-faq/shell/.html

  You can also get it via email by emailing mail-server@xxxxxxxxxxxx
  with, in the body of the message, `send faqs/unix-faq/shell/zsh'.

  The latest version of this FAQ is also available directly from any
  of the zsh archive sites listed in question 1.6.

  There is now a preliminary version of a reference card for
  zsh 3.0, which you can find (while it's being developed) at
    http://www.ifh.de/~pws/computing/refcard.ps
  This is optimised for A4 paper. The LaTeX source is in the
  same place with the extension .tex.  It is not a good place
  from which to learn zsh for the first time.

  (As a method of reading the following in Emacs, you can type \M-2
  \C-x $ to make all the indented text vanish, then \M-0 \C-x $
  when you are on the title you want.)

  For any more eclectic information, you should contact the mailing
  list:  see question 5.2.

--- End of general information, changed items follow in full ---

1.5: What's the latest version?

  Zsh 3.0.5 is the latest production version, however a test version of
  3.0.6 is doing the rounds and should be released soon. The new major
  number 3.0 largely reflects the considerable internal changes in zsh to
  make it more reliable, consistent and (where possible) compatible.  Those
  planning on upgrading their zsh installation should take a look at the
  list of incompatibilities at the end of 5.1.  This is longer
  than usual due to enhanced sh, ksh and POSIX compatibility.

  The beta version 3.1.5 is also available.  Development of zsh is
  usually patch by patch, with each intermediate version publicly
  available.  Note that this `open' development system does mean bugs
  are sometimes introduced into the most recent archived version.
  These are usually fixed quickly.

  Note also that as the shell changes, it may become incompatible with
  older versions; see the end of question 5.1 for a partial list.
  Changes of this kind are almost always forced by an awkward or
  unnecessary feature in the original design (as perceived by current
  users), or to enhance compatibility with other Bourne shell
  derivatives, or (most recently) to provide POSIX compliancy.

5.1: What bugs are currently known and unfixed? (Plus recent important changes)

  Here are some of the more well-known ones, very roughly in
  decreasing order of significance.  Many of these can also be counted
  against differences from ksh in question 2.1; note that this applies
  to the latest beta version and that simple bugs are often fixed
  quite quickly.  There is a file Etc/BUGS in the source distribution
  with more detail.

  o  `time' is ignored with builtins and can't be used with `{...}'.
  o  `set -x' (`setopt xtrace') still has a few glitches.
  o  Zsh's notion of the current line number (via $LINENO) is
     sometimes not well handled, particularly when using functions and traps.
  o  In vi mode, `u' can go past the original modification point.
  o  The singlelinezle option has problems with prompts containing escapes.
  o  The `r' command does not work inside `$(...)' or ``...`'
     expansions.   (This is fixed in 3.1.)
  o  `typeset' handling is non-optimal, particularly with regard to
     flags, and is ksh-incompatible in unpredictable ways. 
  o  Nested closures in extended globbing and pattern matching, such as

      [[ fofo = (fo#)# ]]

     were not correctly handled, and there were problems with
     complicated exclusions using `^' or `~'.  (These
     are fixed in version 3.1.3.)

  Note that a few recent changes introduce incompatibilities (these
  are not bugs):

  Changes after zsh 3.0 (3.1.x is still currently in beta):

  o  The options ALWAYS_LAST_PROMPT (return to the line you were
     editing after displaying completion lists) and LIST_AMBIGUOUS
     (show matching files when there are several) are now set by
     default.  This is in response to complaints that too many zsh
     features are never noticed by many users.  To turn them off,
     just put `unsetopt alwayslastprompt listambiguous' in your
     .zshrc file.
  o  history-search-{forward,backward} now only find previous
     lines where the first word is the same as the current one.  For
     example, 

      comp<ESC>p

     will find lines in the history like `comp -edit emacs', but not
     `compress file' any more.  For this reason, `\M-n' and
     `\M-p' use history-beginning-search-{forward,backward} which
     search for a line with the same prefix up to the cursor position.
     From 3.1.6, there is likely to be a different implementation which
     makes this closer (though not identical) to the old behaviour.
     The story for the {up,down}-line-or-search commands is similar.
  o  In vi insert mode, the cursor keys no longer work.  The following
     will bind them:

       bindkey -M viins '^[[D' vi-backward-char '^[[C' vi-forward-char \ 
                      '^[[A' up-line-or-history '^[[B' down-line-or-history

     (unless your terminal requires `^[O' instead of `^[[').  The
     rationale is that the insert mode and command mode keymaps for
     keys with prefixes are now separate.

  Changes since zsh 2.5:

  o  The left hand of an assignment is no longer substituted.  Thus,
     `$1=$2' will not work.  You can use something like `eval
     "$1=\$2"', which should have the identical effect.
  o  Signal traps established with the `trap' builtin are now called with
     the environment of the caller, as in ksh, instead of as a new
     function level.  Traps established as functions (e.g. `TRAPINT()
     {...}') work as before.
  o  The NO_CLOBBER option is now -C and PRINT_EXIT_VALUE -1; they used
     to be the other way around.  (Use of names rather than letters is
     generally recommended.)
  o  `[[' is a reserved word, hence must be separated from
     other characters by whitespace; `{' and `}' are also reserved
     words if the IGNORE_BRACES option is set.
  o  The option CSH_JUNKIE_PAREN has been removed:  csh-like code now
     always does what it looks like it does, so `if ( ... ) ...'
     executes the code in parentheses in a subshell.  To make this
     useful, the syntax expected after an `if', etc., is less strict
     than in other shells.
  o  `foo=*' does not perform globbing immediately on the right
     hand side of the assignment; the old behaviour now requires the
     option GLOB_ASSIGN.  (`foo=(*)' is and has always been the
     consistent way of doing this.)
  o  <> performs redirection of input and output to the specified file.
     For numeric globs, you now need <->.
  o  The command line qualifiers exec, noglob, command, - are now
     treated more like builtin commands:  previously they were
     syntactically special.  This should make it easier to perform
     tricks with them (disabling, hiding in parameters, etc.).
  o  The pushd builtin has been rewritten for compatibility with other
     shells.  The old behavour can be achieved with a shell function.
  o  The current version now uses ~'s for directory stack substitution
     instead of ='s.  This is for consistency:  all other directory
     substitution (~user, ~name, ~+, ...) used a tilde, while
     =<number> caused problems with =program substitution.
  o  The `HISTLIT' option was broken in various ways and has been removed:
     the rewritten history mechanism doesn't alter history lines, making
     the option unnecessary.
  o  History expansion is disabled in single-quoted strings, like other
     forms of expansion -- hence exclamation marks there should not be
     backslashed.
  o  The `$HISTCHARS' variable is now `$histchars'.  Currently both
     are tied together for compatibility.
  o  The PROMPT_SUBST option now performs backquote expansion -- hence
     you should quote these in prompts.  (SPROMPT has changed as a result.)
  o  Quoting in prompts has changed: close parentheses inside ternary
     expressions should be quoted with a %; history is now %!, not
     !.  Backslashes are no longer special.

--- End of changed items, diff from previous version follows ---
Index: zshfaq.txt
===================================================================
RCS file: /pack/anoncvs/zsh/www/FAQ/zshfaq.txt,v
retrieving revision 1.12
retrieving revision 1.13
diff -u -r1.12 -r1.13
--- zshfaq.txt	1999/03/24 10:58:44	1.12
+++ zshfaq.txt	1999/04/23 12:00:30	1.13
@@ -1,16 +1,15 @@
 
 Archive-Name: unix-faq/shell/zsh
-Last-Modified: 1999/03/24
+Last-Modified: 1999/04/23
 Submitted-By: pws@xxxxxxxxxxxxxxxxx (Peter Stephenson)
-Version: $Id: zshfaq.txt,v 1.12 1999/03/24 10:58:44 pws Exp $
+Version: $Id: zshfaq.txt,v 1.13 1999/04/23 12:00:30 pws Exp $
 Posting-Frequency: Monthly
 Copyright: (C) P.W. Stephenson, 1995--1999 (see end of document)
 
-Changes since issue posted January 1999:
+Changes since issue posted March 1999:
 
-1.1  Mention plain text FAQ location.
-5.3  Added list of goodies which will appear in version 3.1.6,
-     separate from much-truncated wish-list.
+1.5  Mention 3.0.6 should appear soon
+5.1  Update on history-search-backward saga
 
 This document contains a list of frequently-asked (or otherwise
 significant) questions concerning the Z-shell, a command interpreter
@@ -227,12 +226,13 @@
 
 1.5: What's the latest version?
 
-  Zsh 3.0.5 is the latest production version. The new major number 3.0
-  largely reflects the considerable internal changes in zsh to make it
-  more reliable, consistent and (where possible) compatible.  Those
-  planning on upgrading their zsh installation should take a look at
-  the list of incompatibilities at the end of 5.1.  This is
-  longer than usual due to enhanced sh, ksh and POSIX compatibility.
+  Zsh 3.0.5 is the latest production version, however a test version of
+  3.0.6 is doing the rounds and should be released soon. The new major
+  number 3.0 largely reflects the considerable internal changes in zsh to
+  make it more reliable, consistent and (where possible) compatible.  Those
+  planning on upgrading their zsh installation should take a look at the
+  list of incompatibilities at the end of 5.1.  This is longer
+  than usual due to enhanced sh, ksh and POSIX compatibility.
 
   The beta version 3.1.5 is also available.  Development of zsh is
   usually patch by patch, with each intermediate version publicly
@@ -1695,8 +1695,9 @@
      `compress file' any more.  For this reason, `\M-n' and
      `\M-p' use history-beginning-search-{forward,backward} which
      search for a line with the same prefix up to the cursor position.
-     It is possible to write functions which go a little closer to the
-     original behaviour; further changes are still possible.
+     From 3.1.6, there is likely to be a different implementation which
+     makes this closer (though not identical) to the old behaviour.
+     The story for the {up,down}-line-or-search commands is similar.
   o  In vi insert mode, the cursor keys no longer work.  The following
      will bind them: